I Built a Crew of AI Agents That Review Code Like a Real Team — Then Watched Them Argue With SigNoz

I Built a Crew of AI Agents That Review Code Like a Real Team — Then Watched Them Argue With SigNoz My submission for the Agents of SigNoz Hackathon (Track: AI & Agent Observability) The idea Most "AI code review" demos are one LLM call with a clever prompt. That's fine, but it doesn't reflect how review actually works on a real team — different people care about different things. Someone obsesses over edge cases. Someone else nitpicks naming. Someone else only cares if it's going to be slow in production. And then someone has to actually make the call on whether the PR merges. So I built that as a crew: a Logic Reviewer , a Style Reviewer , and a Performance Reviewer — three independent agents, each with a narrow system prompt that tells them to only look at their lane — followed by a Moderator agent that reads all three opinions and produces one final verdict, calling out disagreement when it happens. The interesting engineering problem wasn't the prompting. It was: once you have four chained LLM calls, how do you actually know what's happening inside your own system? Why observability, not just another agent demo Once I had the crew working, I had zero visibility into it. Four sequential API calls, each with its own latency and token cost, and all I had was print() statements. If the moderator gave a weird verdict, I had no fast way to tell whether the logic reviewer hallucinated an issue, or the moderator just summarized badly. If a run felt slow, I couldn't tell which of the four agents was the bottleneck. This is exactly the gap SigNoz is built for, so I instrumented every agent call with OpenTelemetry: Each specialist agent and the moderator run inside their own span ( agent.logic_reviewer , agent.style_reviewer , agent.performance_reviewer , agent.moderator ) All four are nested under one parent span, code_review_session , so a single review run shows up as one trace with four child spans Every span carries the attributes that actually matter for debugging a