Tianyang Liu

Crowdsourced evaluation platforms such as Chatbot Arena enable real-time human assessment of model responses, but evaluating LLM-generated code remains challenging due to long outputs and the need to reason about execution behavior. We introduce BigCodeArena, an open human evaluation platform for code generation with an on-the-fly execution backend. BigCodeArena executes LLM-generated code and allows humans to interact directly with execution processes and outcomes. We collect over 14K code-centric conversations across 10 widely used LLMs, spanning 10 programming languages and 8 execution environments, including more than 4.7K multi-turn samples with pairwise human preferences. Our analysis reveals fine-grained preferences across tasks, languages, and frameworks. With the collected data, we construct two benchmarks: BigCodeReward, which measures alignment between reward models and human preferences, and AutoCodeArena, an automated Elo-style benchmark for code generation. Results show that execution feedback improves preference modeling, and that proprietary models such as GPT-5 and Claude-4 variants remain strong performers.

LLM agents now perform strongly in software engineering, deep research, GUI automation, and various other applications, while recent agent scaffolds and models are increasingly integrating these capabilities into unified systems. Yet, most evaluations still test these capabilities in isolation, which leaves a gap for more diverse use cases that require agents to combine different capabilities. We introduce CocoaBench, a benchmark for unified digital agents built from human designed, long horizon tasks that require flexible composition of vision, search, and coding. Tasks are specified only by an instruction and an automatic evaluation function over the final output, enabling reliable and scalable evaluation across diverse agent infrastructures. We also present CocoaAgent, a lightweight shared scaffold for controlled comparison across model backbones. Experiments show that current agents remain far from reliable on CocoaBench, with the best evaluated system achieving only 45.1% success rate. Our analysis further points to substantial room for improvement in reasoning and planning, tool use and execution, and visual grounding.