Title: TAROT: Test-Driven and Capability-Adaptive Curriculum Reinforcement Fine-Tuning for Code Generation
Primary area: foundation or frontier models, including LLMs
Keywords: Large Language Model, Code Generation, Curriculum Learning, Reinforcement Learning

Abstract: Large Language Models (LLMs) are fundamentally changing the coding paradigm, known as vibe coding, yet synthesizing algorithmically sophisticated and robust code still remains a critical challenge. Incentivizing the deep reasoning capabilities of LLMs is essential to overcome this hurdle. Reinforcement Fine-Tuning (RFT) has emerged as a promising strategy to address this need. However, most existing approaches overlook the heterogeneous difficulty and granularity inherent in test cases, leading to an imbalanced distribution of reward signals and consequently biased gradient updates during training. To address this, we propose TAROT, Test-driven and cApability-adaptive cuRriculum reinfOrcement fine-Tuning. TAROT systematically constructs, for each problem, a four-tier test suite (basic, intermediate, complex, edge), providing a controlled difficulty landscape for curriculum design and evaluation. Crucially, TAROT decouples curriculum progression from raw reward scores, enabling capability-conditioned evaluation and principled selection from a portfolio of curriculum policies rather than incidental test-case difficulty composition. This design fosters stable optimization and more efficient competency acquisition. Extensive experimental results reveal that the optimal curriculum for reinforcement fine-tuning in code generation is closely tied to a model’s inherent capability, with less capable models achieving greater gains with an easy-to-hard progression, whereas more competent models excel under a hard-first curriculum. TAROT provides a reproducible method that adaptively tailors curriculum design to a model's capability, thereby consistently improving the functional correctness and robustness of the generated code. All code and data are released to foster reproducibility and advance community research at https://anonymous.4open.science/r/TAROT-B675.