messages listlengths 2 2 | metadata unknown |
|---|---|
[
{
"role": "user",
"content": "Tune Kafka consumer lag in order pipeline during peak traffic. Give tuning guide."
},
{
"role": "assistant",
"content": "Measure lag per partition, processing time, fetch rate, GC pauses. Scale partitions and consumer instances matching key ordering constraints. Inc... | {
"domain": "backend",
"task_type": "optimization",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Pagination offset limit skips duplicates new rows inserted concurrently missing items. How to fix stable cursor pagination"
},
{
"role": "assistant",
"content": "Offset shifts when inserts occur before current page causing skipped or duplicated items and poor user e... | {
"domain": "backend",
"task_type": "api_debugging",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Design globally distributed backend with CRDTs, conflict resolution, and causal consistency."
},
{
"role": "assistant",
"content": "Model shared state as operation based CRDTs like OR-Set and LWW registers with hybrid logical clocks for causality. Replicate via Kafk... | {
"domain": "backend",
"task_type": "architecture",
"difficulty": "expert"
} |
[
{
"role": "user",
"content": "My FastAPI app crashes with AttributeError: 'NoneType' object has no attribute 'id' when accessing current_user.id. Traceback points to endpoint after Depends(get_current_user). The dependency returns None on missing token instead of raising. How to fix?"
},
{
"role": "... | {
"domain": "backend",
"task_type": "traceback",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Optimize JSON serialization in hot API using orjson and response model exclusion."
},
{
"role": "assistant",
"content": "Standard json plus full ORM dump wastes CPU and bandwidth on unused fields. Switch to orjson for 2x faster dumps and use response_model with excl... | {
"domain": "backend",
"task_type": "optimization",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Android SharedPreferences OAuth cleartext backup rooted reads token theft. Secure storage with Keystore and backup rules"
},
{
"role": "assistant",
"content": "Cleartext preferences with backup enabled exposes tokens to backup extraction or root theft leading to acc... | {
"domain": "backend",
"task_type": "security",
"difficulty": "expert"
} |
[
{
"role": "user",
"content": "Terraform wants recreate RDS engine 14.6 to 14.7 storage drift. How to avoid downtime and data loss during upgrade"
},
{
"role": "assistant",
"content": "Recreation likely from immutable argument change, provider default diff, or parameter group replacement risking ... | {
"domain": "backend",
"task_type": "debugging",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Write backend health check test asserting database connectivity and 200 response."
},
{
"role": "assistant",
"content": "Expose GET /healthz performing SELECT 1 on primary and checking Redis PING, returning {status:'ok', checks:{db:'up', redis:'up'}} with 200 or 503... | {
"domain": "backend",
"task_type": "testing",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Threat model OAuth2 login flow for backend with PKCE. List mitigations."
},
{
"role": "assistant",
"content": "Map assets tokens, user data, trust boundaries browser, backend, IdP. Threats: code interception, CSRF, open redirect, token leakage via logs. Mitigations:... | {
"domain": "backend",
"task_type": "security",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Implement Postgres partitioning by month for 500M row events table with retention."
},
{
"role": "assistant",
"content": "Create range partition by created_at monthly, template with indexes on tenant and id. Automate pg_partman creation 3 months ahead. Detach and dr... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Add unit tests for password hashing utility using bcrypt."
},
{
"role": "assistant",
"content": "Test hash_password returns different salts for same input, verify_password succeeds for correct and fails for wrong, and handles unicode. Mock bcrypt cost low for speed ... | {
"domain": "backend",
"task_type": "testing",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Implement idempotent webhook receiver for payment provider with signature verification."
},
{
"role": "assistant",
"content": "Expose POST endpoint verifying HMAC signature with timing-safe compare and timestamp tolerance to prevent replay. Store event id unique con... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Explain REST pagination, filtering, and sorting conventions for a model registry API."
},
{
"role": "assistant",
"content": "Use cursor based pagination with opaque next_token for stable results under inserts, falling back to page number only for small static lists.... | {
"domain": "backend",
"task_type": "instruction",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Review this FastAPI pagination: @app.get('/x') def x(page: int = 1): return items[(page-1)*10:page*10]. No validation, no total, magic numbers. Provide reviewed version with Query validation and envelope."
},
{
"role": "assistant",
"content": "Missing validation all... | {
"domain": "backend",
"task_type": "code_review",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Review REST pagination returning all rows no limits verbose errors. Production fix?"
},
{
"role": "assistant",
"content": "Issues are unbounded result causing OOM, DoS, and stack leakage aiding attackers. Implement keyset pagination limit 50 max 100 with total count... | {
"domain": "backend",
"task_type": "code_review",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Write Express.js GET endpoint returning user list with basic error handling."
},
{
"role": "assistant",
"content": "Implement app.get('/users', async (req,res,next)=>{ try { const users = await db.select(); res.json(users); } catch(err){ next(err);} }); Add centrali... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Implement Redis distributed lock for inventory decrement preventing oversell."
},
{
"role": "assistant",
"content": "Acquire lock with SET key uuid NX PX 5000 ensuring only holder with token can release via Lua script comparing value before DEL to avoid deleting oth... | {
"domain": "backend",
"task_type": "optimization",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Implement consistent hashing for sharding embedding cache."
},
{
"role": "assistant",
"content": "Build hash ring with virtual nodes to distribute keys evenly and minimize remapping on scaling. Use murmur or sha256 for uniform distribution. Assign each cache node mu... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Implement cursor pagination for REST API with stable ordering and total count optimization."
},
{
"role": "assistant",
"content": "Use opaque cursor encoding last seen sort key like created_at plus id to avoid offset drift when rows insert concurrently. Enforce dete... | {
"domain": "backend",
"task_type": "architecture",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Review iOS networking http staging disables ATS ignores SSL delegate true. What change before release for transport security"
},
{
"role": "assistant",
"content": "HTTP plus disabled App Transport Security and blind trust of invalid certificates enables man in middl... | {
"domain": "backend",
"task_type": "code_review",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "My FastAPI GET with list query param fails: /items?tags=a,b expects List[str] but gets single string. How to correctly pass arrays and validate in FastAPI?"
},
{
"role": "assistant",
"content": "FastAPI expects repeated params for List, not comma string, unless cust... | {
"domain": "backend",
"task_type": "api_debugging",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Design CDC pipeline from Postgres WAL to Elasticsearch for search indexing."
},
{
"role": "assistant",
"content": "Deploy Debezium connector reading WAL logical replication slot, publishing row changes to Kafka topics dbserver.schema.table. Consume with sink transfo... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Document backend background job system with retries and DLQ. Include runbook."
},
{
"role": "assistant",
"content": "Describe queue topology, job types, priorities, concurrency. Explain enqueue API with idempotency keys, payload schema, visibility timeout. Detail re... | {
"domain": "backend",
"task_type": "instruction",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Stripe retry same request no key duplicate charges. How to implement idempotency correctly across services and queues"
},
{
"role": "assistant",
"content": "Without Idempotency Key Stripe treats network retries as new charges creating duplicates, disputes, and suppo... | {
"domain": "backend",
"task_type": "api_debugging",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Implement JWT auth with rotating refresh tokens, reuse detection, HttpOnly cookies."
},
{
"role": "assistant",
"content": "Issue short access 15min and refresh 30d JWTs with jti. Store refresh hash in Postgres with revoked flag and parent jti chain. Rotate on each u... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Explain how to structure a FastAPI backend for serving an ML model with validation, logging, and health checks."
},
{
"role": "assistant",
"content": "Create a modular FastAPI app with routers, services, and schemas. Define Pydantic models for request validation inc... | {
"domain": "backend",
"task_type": "instruction",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Describe Dockerizing a backend service with multi-stage builds, healthchecks, and minimal images."
},
{
"role": "assistant",
"content": "Dockerize backends with multi stage builds separating compile and runtime for small secure images. Start from slim official base,... | {
"domain": "backend",
"task_type": "instruction",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Block CSV formula injection in pandas export downloaded by finance users in Excel."
},
{
"role": "assistant",
"content": "Cells starting with equals, plus, or at execute as formulas in Excel enabling exfiltration. Pandas export writes raw strings without sanitizatio... | {
"domain": "backend",
"task_type": "security",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "How do I create a simple POST endpoint in FastAPI that validates input with Pydantic? I need an endpoint to create a user with name and email, returning the created user with an id. Show the full minimal code."
},
{
"role": "assistant",
"content": "Define a Pydantic... | {
"domain": "backend",
"task_type": "instruction",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Explain event driven vs request response for AI agent tool orchestration."
},
{
"role": "assistant",
"content": "Request response suits synchronous tool calls with immediate results and simple error handling. Event driven via queues enables long running agents, retr... | {
"domain": "backend",
"task_type": "instruction",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Debug backend distributed trace gaps from missing context propagation across threads and queues."
},
{
"role": "assistant",
"content": "Gaps stem from contextvars not crossing threads or task queue serialization losing traceparent. Fix by injecting W3C traceparent i... | {
"domain": "backend",
"task_type": "debugging",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Implement Postgres advisory locks for distributed cron deduplication across 5 replicas."
},
{
"role": "assistant",
"content": "Use pg_try_advisory_lock bigint key per job to elect single runner among replicas. Acquire at start, release on completion with timeout 10m... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "FastAPI endpoint returns 422 when posting JSON with datetime field. Debug Pydantic validation mismatch."
},
{
"role": "assistant",
"content": "Pydantic version two strictly validates datetime strings requiring timezone awareness if field is configured as aware. Fail... | {
"domain": "backend",
"task_type": "debugging",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Document backend webhook authentication and retry policy for partner integrators."
},
{
"role": "assistant",
"content": "Explain HMAC SHA256 signature header, timestamp tolerance five minutes, IP allowlist, and TLS requirements. Provide verification code samples in ... | {
"domain": "backend",
"task_type": "instruction",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Design an idempotent payment webhook handler with signature verification and exactly-once processing."
},
{
"role": "assistant",
"content": "Payment webhooks must tolerate retries without double charging. Verify HMAC signatures using raw body and timestamp tolerance... | {
"domain": "backend",
"task_type": "instruction",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Implement JWT authentication in backend with refresh rotation, revocation, and secure cookies."
},
{
"role": "assistant",
"content": "Issue short lived access JWT 15m and rotating refresh 30d stored hashed in DB with reuse detection. Sign with RS256, validate iss au... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Harden file upload API against malware, size abuse, and SSRF."
},
{
"role": "assistant",
"content": "Validate content type by magic bytes not just extension, rejecting mismatched executables masquerading as images. Enforce size limits at reverse proxy and applicatio... | {
"domain": "backend",
"task_type": "security",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "React Native bridge slow 5MB JSON frame drops list scroll. How to optimize transfer virtualization and native filtering"
},
{
"role": "assistant",
"content": "Serializing five megabytes over bridge blocks JavaScript thread causing dropped frames, jank, and high memo... | {
"domain": "backend",
"task_type": "api_debugging",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Handle downstream timeout cascade in order service with deadlines, retries, and fallback cache."
},
{
"role": "assistant",
"content": "Propagate global deadline via context with 2s budget across order and inventory and payment calls to bound tail latency. Set per ho... | {
"domain": "backend",
"task_type": "debugging",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "API shows 401 on preflight OPTIONS due to auth middleware rejecting it. Debug and fix CORS plus auth order."
},
{
"role": "assistant",
"content": "Auth middleware runs before CORS handling and rejects OPTIONS without token, so browser never sees ACAO headers and blo... | {
"domain": "backend",
"task_type": "api_debugging",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Stored XSS markdown renderer script onload comments CSP missing HttpOnly false. How to sanitize harden output and cookies"
},
{
"role": "assistant",
"content": "Renderer outputs raw HTML enabling script execution stealing sessions via stolen cookies and keylogging. ... | {
"domain": "backend",
"task_type": "security",
"difficulty": "expert"
} |
[
{
"role": "user",
"content": "Review Postgres migration ADD COLUMN email TEXT NOT NULL no default 10M rows no concurrent index. Operational risk zero downtime strategy"
},
{
"role": "assistant",
"content": "Adding NOT NULL without default rewrites table and scans ten million rows holding AccessE... | {
"domain": "backend",
"task_type": "code_review",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Debug race condition where two concurrent orders decrement inventory below zero. Propose safe fix."
},
{
"role": "assistant",
"content": "Race occurs from read then write without lock so both threads see stock 1 and both succeed causing oversell. Confirm with concur... | {
"domain": "backend",
"task_type": "debugging",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Implement idempotent POST endpoints in backend using keys, deduplication store, and response replay."
},
{
"role": "assistant",
"content": "Require Idempotency-Key header, store hashed key plus request fingerprint and response for 24h in DB or Redis with unique cons... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Show how to structure a FastAPI service with routers, dependencies, validation, and error handling."
},
{
"role": "assistant",
"content": "Structure FastAPI by routers per domain, dependencies for auth and resources, and pydantic schemas for validation. Organize app... | {
"domain": "backend",
"task_type": "instruction",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Flask traceback NoneType has no attribute split parsing Authorization header on unauthenticated requests. Best fix returning proper 401 JSON"
},
{
"role": "assistant",
"content": "Code assumes Authorization header present and calls get split without None check, cras... | {
"domain": "backend",
"task_type": "traceback",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "My FastAPI app returns 500 CORS errors in browser but curl works. I added CORSMiddleware but frontend at http://localhost:3000 still blocked. My code uses allow_origins=['*'] with allow_credentials=True. What is wrong and how to fix?"
},
{
"role": "assistant",
"cont... | {
"domain": "backend",
"task_type": "debugging",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Create simple Flask hello world route and explain request handling for beginners."
},
{
"role": "assistant",
"content": "Define minimal app with from flask import Flask; app = Flask(__name__); @app.route('/hello') def hello(): return {'message':'hello'}. Run via fla... | {
"domain": "backend",
"task_type": "optimization",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Debug FastAPI 422 validation errors caused by mismatched datetime formats from frontend."
},
{
"role": "assistant",
"content": "Inspect 422 response detail showing loc, msg, and input to pinpoint field. Frontend sends DD-MM-YYYY while Pydantic expects ISO8601. Fix b... | {
"domain": "backend",
"task_type": "debugging",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "How do I handle pagination and filtering in a FastAPI REST list endpoint? I need query params for page, size, and optional search with validation and sane defaults. Show the implementation."
},
{
"role": "assistant",
"content": "Use Query for validated query params ... | {
"domain": "backend",
"task_type": "instruction",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Review Docker Compose setup for security, resource limits, and startup ordering."
},
{
"role": "assistant",
"content": "Check images pinned by digest not latest tag to ensure reproducible secure builds. Verify no privileged mode and read only root filesystem where p... | {
"domain": "backend",
"task_type": "code_review",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Review Kubernetes deployment PR lacking probes, limits, and graceful shutdown."
},
{
"role": "assistant",
"content": "Require liveness /livez and readiness /readyz probes with initialDelay 10s period 10s to prevent premature traffic and restart hangs. Demand resourc... | {
"domain": "backend",
"task_type": "code_review",
"difficulty": "expert"
} |
[
{
"role": "user",
"content": "Compare dense versus hybrid retrieval on our e-commerce catalog with sparse product codes and descriptions."
},
{
"role": "assistant",
"content": "Slice eval by query type: SKU exact, attribute filter, and natural language need. Dense excels on paraphrases but fails... | {
"domain": "backend",
"task_type": "retrieval_analysis",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Design cursor pagination for large activity feed API."
},
{
"role": "assistant",
"content": "Use opaque cursor encoding timestamp plus ID, e.g., base64 of created_at and id. Query where created_at less than cursor ordered desc limit plus one to detect next page. Avo... | {
"domain": "backend",
"task_type": "architecture",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Optimize slow product listing query with N+1 selects and missing indexes."
},
{
"role": "assistant",
"content": "Detect N plus one via query counter showing one query per product for category and images. Fix with eager loading using selectinload for collections to f... | {
"domain": "backend",
"task_type": "optimization",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "My Flask route returns 500 with TypeError: Object of type datetime is not JSON serializable. Traceback in jsonify. Quick fix?"
},
{
"role": "assistant",
"content": "Convert datetime to ISO format before jsonify using isoformat. Set custom JSON provider with Default ... | {
"domain": "backend",
"task_type": "traceback",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Handle backend API errors consistently with RFC7807 problem details and mapped domain errors."
},
{
"role": "assistant",
"content": "Return application problem json with type title status detail instance and extension code. Map ValidationError to 400, AuthError 401 ... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Implement full-text search with Postgres tsvector, ranking, highlight, and pagination."
},
{
"role": "assistant",
"content": "Create GIN index on to_tsvector('english', title||' '||body). Query with plainto_tsquery and ts_rank_cd for ranking. Use ts_headline for hig... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Intermittent 502 from Nginx to upstream inference service. How to triage?"
},
{
"role": "assistant",
"content": "Check upstream timeouts, keepalive mismatches, and worker crashes causing closed connections. Review Nginx error log for upstream prematurely closed and ... | {
"domain": "backend",
"task_type": "traceback",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Build CDC pipeline from Postgres to warehouse with Debezium, schema evolution, and backfill."
},
{
"role": "assistant",
"content": "Deploy Debezium connector reading WAL with slot to capture inserts updates deletes without query polling. Publish to Kafka topics per ... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "My FastAPI file upload returns 400 with large files over 10MB. I use UploadFile but read entire file into memory. How to handle large uploads with streaming and limits?"
},
{
"role": "assistant",
"content": "Reading whole file exhausts memory and hits proxy limits. ... | {
"domain": "backend",
"task_type": "api_debugging",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Stripe traceback No such payment intent when confirming frontend backend test live keys mismatch. How to fix environment handling safely"
},
{
"role": "assistant",
"content": "Frontend using live publishable key while backend creates intent with test secret causes i... | {
"domain": "backend",
"task_type": "traceback",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Beginner question: backend A B test shows 55 vs 45 conversions out of 200 users. Is new version better?"
},
{
"role": "assistant",
"content": "With only 200 users 55 versus 45 conversions is not conclusive evidence. Compute rates 55 percent versus 45 percent and run... | {
"domain": "backend",
"task_type": "experiment_analysis",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Optimize GraphQL N+1 with DataLoader batching and field level caching."
},
{
"role": "assistant",
"content": "Identify N plus one via tracing showing per author query for each book in list resolver. Introduce DataLoader per request that batches author IDs into singl... | {
"domain": "backend",
"task_type": "optimization",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Fix FastAPI endpoint returning 500 due to detached SQLAlchemy session after request."
},
{
"role": "assistant",
"content": "The error occurs when lazy loading relationships after session close. Fix by eager loading with selectinload or joinedload in the query, or by... | {
"domain": "backend",
"task_type": "debugging",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "How do I structure simple CRUD with FastAPI and SQLAlchemy without N+1 and with validation? Need beginner guide."
},
{
"role": "assistant",
"content": "Define pydantic schemas for create and read separating input from output, SQLAlchemy models with relationships, an... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Implement request id propagation with structlog contextvars across FastAPI and Celery."
},
{
"role": "assistant",
"content": "Generate uuid request_id in middleware, bind via contextvars and structlog. Propagate to Celery via task headers and downstream HTTP X-Reque... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Harden multi tenant JWT validation against algorithm confusion attacks."
},
{
"role": "assistant",
"content": "Enforce explicit alg allowlist RS256 and reject none, never trust header alg. Fetch JWKS per issuer with strict iss and aud validation scoped by tenant. Ca... | {
"domain": "backend",
"task_type": "security",
"difficulty": "expert"
} |
[
{
"role": "user",
"content": "Design saga orchestration for distributed checkout across payments, inventory, shipping."
},
{
"role": "assistant",
"content": "Model checkout as saga orchestrator issuing commands reserve_inventory, charge_payment, schedule_shipping with compensations release_inven... | {
"domain": "backend",
"task_type": "architecture",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Design zero downtime migration for 500M row embeddings table."
},
{
"role": "assistant",
"content": "Create new table with desired schema and backfill in batches with checksums, tracking progress via watermark column. Use triggers or CDC to capture writes during bac... | {
"domain": "backend",
"task_type": "architecture",
"difficulty": "expert"
} |
[
{
"role": "user",
"content": "Implement Redis caching with TTL, cache aside, and stampede prevention for product API."
},
{
"role": "assistant",
"content": "Apply cache aside pattern where application checks Redis first then loads from Postgres on miss and populates cache with TTL like 300 secon... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Implement async worker pool for image thumbnailing with bounded concurrency and backpressure."
},
{
"role": "assistant",
"content": "Create asyncio Queue maxsize fifty holding image jobs to enforce backpressure on upload bursts. Spawn eight workers consuming with aw... | {
"domain": "backend",
"task_type": "optimization",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Optimize Redis session storage with TTL and serialization improvements."
},
{
"role": "assistant",
"content": "Store sessions as MessagePack instead of JSON to cut size 30 percent and CPU. Set TTL 30min with sliding refresh on activity. Use namespaced keys sess:{id}... | {
"domain": "backend",
"task_type": "optimization",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Python traceback TypeError unhashable list using list dict key caching API params. How to fix caching with hashable keys correctly"
},
{
"role": "assistant",
"content": "Lists are mutable and unhashable so cannot serve as dictionary keys, causing TypeError on cache ... | {
"domain": "backend",
"task_type": "traceback",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Optimize Postgres slow query on orders by date with EXPLAIN and index strategy."
},
{
"role": "assistant",
"content": "Run EXPLAIN ANALYZE showing Seq Scan on 5M rows filtering created_at range. Create B-tree index CREATE INDEX CONCURRENTLY idx_orders_created ON ord... | {
"domain": "backend",
"task_type": "optimization",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "npm traceback EINTEGRITY EAI AGAIN overlapping lock files install killed mid run. How to recover cleanly deterministic install"
},
{
"role": "assistant",
"content": "Killed install leaves partial node modules and corrupted cache with integrity mismatch plus DNS retr... | {
"domain": "backend",
"task_type": "traceback",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "SwiftUI list freezes loading high res network images memory spikes scrolling janky. How to fix image pipeline with downsampling and cache"
},
{
"role": "assistant",
"content": "Loading full resolution images on main thread without downsampling exhausts memory, block... | {
"domain": "backend",
"task_type": "debugging",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "How to prevent basic XSS and injection in FastAPI templates? I return f'<h1>{name}</h1>' directly from query param. Show safe version."
},
{
"role": "assistant",
"content": "Direct string interpolation renders attacker script. Use Jinja2 autoescape or HTML escape. E... | {
"domain": "backend",
"task_type": "security",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Review React useEffect fetching user mount no deps array setState after fetch no cleanup no error. What to change for correctness"
},
{
"role": "assistant",
"content": "Missing dependency array runs effect after every render causing infinite fetch loop; no cleanup s... | {
"domain": "backend",
"task_type": "code_review",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Review my JWT auth middleware that stores tokens in localStorage and skips verification on public paths via string contains. Issues?"
},
{
"role": "assistant",
"content": "Flag XSS theft via localStorage, use HttpOnly SameSite cookies instead. String contains for pu... | {
"domain": "backend",
"task_type": "code_review",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Design event driven order processing with Kafka outbox pattern for reliable delivery."
},
{
"role": "assistant",
"content": "Use outbox table in same Postgres transaction as order write to guarantee atomic publish intent, then relay worker polls and publishes to Kaf... | {
"domain": "backend",
"task_type": "architecture",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "SQLAlchemy OperationalError too many connections pytest xdist Pool 20 times 8 workers. How to fix test pooling and isolation"
},
{
"role": "assistant",
"content": "Parallel workers each open independent pools multiplying connections beyond Postgres max connections a... | {
"domain": "backend",
"task_type": "traceback",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Design pagination and filtering for a product catalog API with cursor stability."
},
{
"role": "assistant",
"content": "Use cursor pagination with opaque base64 cursor encoding sort key and id for stable results under writes. Support limit clamped to max 100, sort w... | {
"domain": "backend",
"task_type": "architecture",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "How to structure FastAPI routers for users and orders with versioning? Show APIRouter usage, prefix, tags, and main app inclusion for v1."
},
{
"role": "assistant",
"content": "Split by resource with APIRouter, version prefix at include time to allow v2 later. Examp... | {
"domain": "backend",
"task_type": "architecture",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "NextJS API CORS error frontend Vercel calls backend EC2 preflight OPTIONS 404. How to configure correctly with credentials and allowlist"
},
{
"role": "assistant",
"content": "Browser blocks cross origin without Access Control Allow Origin on actual and preflight re... | {
"domain": "backend",
"task_type": "debugging",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "How to test database transactions with rollback isolation in FastAPI and SQLAlchemy? I need each test to start clean without truncating tables. Show fixture with nested transaction."
},
{
"role": "assistant",
"content": "Use outer transaction with savepoint rollback... | {
"domain": "backend",
"task_type": "testing",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Review Postgres code string concat queries no transactions unclosed clients. Secure fix?"
},
{
"role": "assistant",
"content": "Issues are SQL injection, partial writes, and connection leaks. Replace concat with parameterized $1 placeholders via asyncpg or psycopg. ... | {
"domain": "backend",
"task_type": "code_review",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Secure backend against SQL injection, XSS, CSRF, SSRF with validation and allowlists."
},
{
"role": "assistant",
"content": "Prevent SQLi with parameterized ORM queries forbidding string interpolation, XSS with output encoding and CSP headers, CSRF with SameSite coo... | {
"domain": "backend",
"task_type": "security",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Postgres query with JOIN on 10M rows does seq scan 8s. EXPLAIN shows no index on foreign key. How to optimize?"
},
{
"role": "assistant",
"content": "Add B-tree index on foreign key and filter columns, then ANALYZE. Rewrite to select only needed columns, add composi... | {
"domain": "backend",
"task_type": "optimization",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "S3 presigned URL 403 SignatureDoesNotMatch content-type mismatch clock skew. Fix?"
},
{
"role": "assistant",
"content": "Root cause is client sending different Content-Type than signed plus clock drift over 15m invalidating signature. Sign exact headers including co... | {
"domain": "backend",
"task_type": "api_debugging",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Prevent SQL injection in raw psycopg2 queries with dynamic filters and sorting. Show safe pattern."
},
{
"role": "assistant",
"content": "Injection comes from f string interpolation of user input into SQL, allowing breakout via quotes or stacked queries. Always use ... | {
"domain": "backend",
"task_type": "security",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Create simple health check endpoint for backend service with DB and Redis checks."
},
{
"role": "assistant",
"content": "Implement GET /healthz returning 200 with status ok, version, uptime. Check DB with SELECT 1 and Redis PING with 500ms timeout, reporting depende... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "My Node app crashes reading map of undefined when API returns null for items. How to make rendering defensive and type safe"
},
{
"role": "assistant",
"content": "API contract allows null or missing items but code assumes array and calls items map directly throwing ... | {
"domain": "backend",
"task_type": "debugging",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Implement FastAPI pagination with limit offset for products endpoint handling 100k rows."
},
{
"role": "assistant",
"content": "Define query params limit: int = Query(20, ge=1, le=100) and offset: int = Query(0, ge=0). Query with SELECT ... LIMIT :limit OFFSET :offs... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "How to test FastAPI dependencies with overridden auth for different roles? I need admin and user tests without real JWT. Show dependency_overrides pattern with cleanup."
},
{
"role": "assistant",
"content": "Override auth dependency to return fake users per test, cl... | {
"domain": "backend",
"task_type": "testing",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "My Node backend returns 500 on POST due to unhandled promise rejection. How to debug?"
},
{
"role": "assistant",
"content": "Enable unhandledRejection logging and check stack for failing async handler missing try catch or error middleware. Reproduce with curl and mi... | {
"domain": "backend",
"task_type": "debugging",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Explain idempotency keys for POST payment endpoints and how to implement them safely."
},
{
"role": "assistant",
"content": "Idempotency keys let clients retry safely by keying request fingerprint to stored response, preventing double charges on timeouts. Require cl... | {
"domain": "backend",
"task_type": "instruction",
"difficulty": "intermediate"
} |
[
{
"role": "user",
"content": "Explain keyset pagination for a FastAPI Postgres orders API and why it beats offset for large tables."
},
{
"role": "assistant",
"content": "Use keyset pagination with created_at plus id as tiebreaker to avoid offset drift and keep queries indexed and stable under c... | {
"domain": "backend",
"task_type": "instruction",
"difficulty": "beginner"
} |
[
{
"role": "user",
"content": "Liveness kills slow Java 90s startup probe 10s restart loop. How to fix startup versus liveness versus readiness probes"
},
{
"role": "assistant",
"content": "Aggressive liveness during startup causes restart loop where app never becomes ready despite eventual succe... | {
"domain": "backend",
"task_type": "api_debugging",
"difficulty": "advanced"
} |
[
{
"role": "user",
"content": "Implement backend saga coordinator with state persistence, compensation, timeouts, and monitoring."
},
{
"role": "assistant",
"content": "Persist saga steps with states pending compensating done in DB, drive via state machine with idempotent handlers and heartbeat t... | {
"domain": "backend",
"task_type": "implementation",
"difficulty": "advanced"
} |
PRIME AI Engineering Dataset
A structured instruction dataset for training AI engineering assistants.
PRIME AI Engineering is designed to help language models develop practical capabilities across AI development, software engineering, and modern machine learning workflows. It combines diverse engineering tasks in a consistent conversational format suitable for supervised fine-tuning (SFT).
Overview
- 4,605 training examples
- 499 validation examples
- 499 test examples
- 5,603 examples across all splits
- Format: JSON Lines (
.jsonl) - Data structure: Conversational messages with structured metadata
- Primary use case: Instruction fine-tuning of AI engineering assistants
What Makes This Dataset Useful?
Broad AI Engineering Coverage
The dataset covers multiple interconnected areas of engineering:
- Python Development: Functions, algorithms, debugging, exceptions, and code quality.
- LLM Engineering: Language model workflows, inference, optimization, and integration.
- Retrieval-Augmented Generation: Retrieval pipelines, context handling, and retrieval analysis.
- Machine Learning: Classical ML concepts, model behavior, and experimentation.
- Deep Learning: PyTorch workflows and model implementation.
- Backend Engineering: APIs, application architecture, and system integration.
- Production AI: Testing, security, reliability, performance, and deployment-oriented problem solving.
- Software Quality: Code review, validation, edge cases, and maintainability.
Diverse Engineering Tasks
Examples are organized around practical task types, including:
- Implementation and code generation
- Debugging and traceback diagnosis
- Architecture and system design
- Code review and testing
- Performance optimization
- Security and defensive programming
- Experiment analysis
- Retrieval and API debugging
This diversity makes the dataset suitable for developing assistants that can do more than explain concepts: they can also reason through engineering problems and produce actionable technical responses.
Consistent Conversational Structure
Each example follows a predictable message structure, helping simplify dataset loading, preprocessing, and conversion to a model-specific chat template.
The structured format separates conversational content from metadata, making examples easier to inspect, filter, categorize, and extend.
Separate Training and Evaluation Splits
The dataset provides distinct training, validation, and test splits:
| Split | Examples | Purpose |
|---|---|---|
| Train | 4,605 | Model fine-tuning |
| Validation | 499 | Validation and model selection |
| Test | 499 | Final evaluation |
| Total | 5,603 |
Keeping evaluation splits separate supports more reliable measurement of model performance.
Dataset Format
The dataset uses JSON Lines (.jsonl), with one complete JSON object per line.
Each record contains two primary fields:
| Field | Type | Description |
|---|---|---|
messages |
Array | Ordered user and assistant messages |
metadata |
Object | Structured labels describing the example |
Example Record
{
"messages": [
{
"role": "user",
"content": "Explain why batching can improve inference throughput in a language model."
},
{
"role": "assistant",
"content": "Batching allows a model to process multiple input sequences in a shared forward pass, improving hardware utilization and throughput. The trade-off is that larger batches can increase memory consumption and waiting time."
}
],
"metadata": {
"domain": "LLM Engineering",
"task_type": "Instruction",
"difficulty": "Intermediate"
}
}
This is an illustrative example of the schema, not a claim that the exact record appears in the dataset.
Message Structure
Each example contains:
- A
usermessage describing a question, task, or engineering problem. - An
assistantmessage containing the corresponding response.
Messages are ordered explicitly by role, providing a straightforward representation for conversion into the chat template required by a target language model.
Metadata Structure
Metadata provides additional context for organizing and analyzing examples.
domain: The primary technical subject.task_type: The category of engineering task.difficulty: The assigned difficulty level.
These fields support filtering, category-level analysis, and targeted experimentation.
Recommended Use Cases
Supervised Fine-Tuning (SFT)
Use the training split to adapt a pretrained instruction-following model to AI engineering tasks.
AI Engineering Assistants
Develop assistants focused on programming, LLM applications, RAG systems, debugging, and engineering workflows.
Domain-Specific Model Adaptation
Experiment with LoRA or QLoRA to adapt models such as Qwen-family instruct models to this technical domain.
Evaluation and Experimentation
Use the validation split to compare training configurations and the test split for final evaluation on held-out examples.
Engineering Research
Study how dataset composition, task diversity, and fine-tuning strategies affect technical response quality.
Compatibility
The dataset's conversational representation is suitable for preprocessing into supervised fine-tuning formats used by modern chat models.
Before training, map the messages field to the target model's expected chat template and verify tokenizer compatibility. The JSONL representation itself does not guarantee direct compatibility with every training framework.
Important Note
The dataset is intended for experimentation and model adaptation. Its structural consistency does not guarantee that every technical answer or code example is correct. Evaluate fine-tuned models on independent tasks and relevant tests before using them in production.
Summary
PRIME AI Engineering provides a structured, multi-domain foundation for fine-tuning AI engineering assistants. Its combination of conversational examples, task-oriented diversity, metadata labels, and separate evaluation splits makes it suitable for controlled SFT experiments and further development of technical language models.
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