Position: Senior Backend Engineer (Blockchain)
Company: VP Team
Experience required: 3y
Category: .NET
English level: upper
Published: 2022-09-01T00:00:00+03:00

**What are we doing?**

Linen Wallet is a wallet and login to access Web3 and securely store crypto assets with multiple signatures (security keys). Web3 is the Internet’s next evolution with built-in native assets: gaming, financial, collectible, etc. Web3 is based on blockchain technologies.

Most of our early users are investors in our company. We have attracted more than $6 million of investments from leading industrial venture investors (Coinbase Ventures, Polychain Capital, HashKey) to make it convenient and safe for users to interact with Web3, including decentralized finance, games, ownable media (NFT), and so on.

**Why are we doing this?**

Assets (game artifacts, loyalty points, financial) issued on blockchains will be an integral part of most apps we use today. There are technical features of storing such assets, mainly related to the secure storage of access keys to accounts in blockchains. It is very important to us that Web3 users around the world are able to not compromise between security and ease of use of the wallet.

**How are we doing?**

Unlike regular wallets, which use seed phrases to backup and restore access to the wallet, we use smart contracts to store crypto assets and multi-signature technology to exclude a single point of failure. The multi-signature design also makes Linen Wallet more user-friendly and lowers the barriers to entry into Web3.

**How old is the project? What stage is it at?**

The project is at the stage of active development, over a year on the market.

**What to do in a project?**

Build reliable and secure server applications;
Take responsibility for the full cycle of backend development and for the code base;
Collaborate with a cross-functional team of engineers, designers, and founders to build a highly reliable, fault-tolerant, and scalable API;
Develop and maintain automated tests and system monitoring that you send to our users and actively fix issues that may arise;
Investigate and fix non-trivial bugs and performance issues;

As an example, here are a couple of tasks on the backend that we dealt with:
Integration of new APIs and smart contracts: connection of a new DeFi protocol that generates interest on the user's deposit.
Collection and processing of data from smart contracts, for example, to analyze user portfolios.
User transaction processing: you can open Linen wallet and connect by QR code to any application that supports blockchain connection. After a transaction is made in a third-party application, our wallet transfers it to the backend, which processes it, forms a transaction, and sends it to the blockchain.

**Who are we looking for?**

We are looking for a skilled Senior Backend Engineer with experience building backend systems. You will be working on the Linen App, one of the first Web3 cryptocurrency wallets and logins that doesn't require you to write out a seed phrase.

This is a modern application based on public blockchains, not proprietary financial APIs.

**What professional skills are important to us?**

4+ years of experience in developing backend systems and working in a team environment.
Knowledge of 1+ programming languages ​​and frameworks for backend development, such as .net core, golang, python, etc.
Solid background in Computer Science.
Proven interest in blockchain technology, NFT, and/or decentralized finance (DeFi) (finished courses, webinars, participating in hackathons, etc.)
Expertise in creating, testing, releasing, and maintaining server applications.
Understanding how microservices are structured, SOA, API architecture principles, and cloud design patterns.
Experience managing and integrating with NoSQL and relational databases (eg MongoDB, PostgreSQL).
Ability to design architecture and build server applications from top to bottom.
Experience with basic setup and work with Docker, Kubernetes, CI / CD.
Knowledge and experience in building secure and resilient APIs.
At least basic knowledge of cryptography concepts and algorithms.
The desire to solve complex technical problems and do them effectively.
Developed communication skills and the ability to quickly absorb a large amount of new information.
Strategic thinking and the ability to approach the problem creatively with a strong analytical mind.
English – for reading documentation and communicating with team members.

**Nice to have:**

experience with .net core stack;
general understanding of blockchain technology’s principles;
experience with products users love, with a focus on finance, security, or UX;
experience in owning any crypto asset.


**Why was the position opened?**

Because of product development.

**Current team structure?**

2 iOS, 2 backend, 1 android, 1 designer, 1 product manager, 1 QA, 1 DevOps, 1 growth marketer, CTO, CEO.

**Where are the people who make technical decisions on the project located?**

CEO and Founder Vitaly Bahachuk is primarily responsible for business development and fundraising. He is a former Wall Street investment banker.
Founder/CTO  Alex Bazhanau is a distributed systems engineer with experience in blockchain.
Both are based in San Francisco.

**The conditions:**

Is there a trial period, and how long does it last? Yes, 3 months.
Overtime, how often, and what is the payment approach? Overtime doesn't happen often. Compensation: an extra day off.
What is the work schedule? Flexible.
Is it possible to work remotely? Position completely remote
A number of vacation days? Unlimited vacation.
Is relocation outside Ukraine possible, and how is the company ready to support it? We are ready to discuss it after 1-2 years of joint work. We can support you financially and legally (through partners). But on the condition that the person establishes oneself as a key member of the team during this time.
When, how, and in what currency is a salary paid? It is paid in dollars to a currency account. There is the possibility of paying with stablecoins.

**The process:**

Is there a test task? No.
Interview in English? No.
Who reviews the resume? CTO.
How many stages of the interview, with whom?
intro call with a recruiter (30 mins)
technical interview + coding task: 2 hours
call with CEO: 1 hour