Software Engineer, Queryable Debugging

About the role

Inquest replaces log-based debugging of agent runs with questions answered from a recording: what was this value, who last wrote it, what was called, how did it change. You will build the query language and the partial-replay engine that answers each query by re-executing only the window it needs, with multithreading support.

What you will do

• Design the query model: State_at, Last_write, Call_history, Value_history, Join
• Build partial replay that re-executes the minimum window to answer a query
• Support multithreaded and multi-process recordings
• Ship CLI and JSON interfaces, then an interactive timeline view
• Measure and publish wall-clock and rerun savings against log-based debugging

What we are looking for

• Experience building developer tools: debuggers, tracers, profilers, or query engines
• Strong systems programming in C++ or Rust, and comfort in Python
• Understanding of record-and-replay or time-travel debugging approaches

Nice to have

• Experience with LLM agent frameworks and how they fail in practice
• Prior work on query languages or execution engines