Meet an unfamiliar repository
Trace the behavior. Ask precise questions. Form a hypothesis before reaching for a fix.
The repository is your interview
Beyond the
right answer.
Practice the work behind great engineering.
Read real code. Explain
your thinking.
Make a change you can prove.
Real repositoriesEvidence-backed feedbackYour AI. Your judgment.
REPOROUND / WORKBENCHProduct preview
Webhook retry incident02 / DIAGNOSE
EXPLORER
⌄ src
delivery.py M
⌄ tests
test_delivery.py
THE BRIEF
A temporary sender failure suppresses the next delivery attempt.
PythonState machines● delivery.py ×
12 def process_job(job, sender): 13 if job.delivered: 14 return 15 16 # When is an attempt complete? 17 sender.send(job.payload) 18 job.delivered = True 19 20 # Every state transition needs evidence.
↳Context pin · delivery.py:17
REASONING LEDGEREvidence connects the dots
HypothesisThe attempt is marked complete before delivery succeeds.↗ code pin
VerifyFail once. Retry. Assert exactly one successful delivery.↗ test plan
⌘ Code◎ Reasoning✓ VerificationIllustrative content
BUILT FOR THE WAY ENGINEERS ACTUALLY WORK
DebuggingCode comprehensionAI patch reviewRegression testing
A better practice loop
The answer is only
part of the story.
Interviews test more than syntax. Practice navigating ambiguity, making tradeoffs, and connecting a claim to something you actually verified.
Make your reasoning visible
Pin an observation to code, weigh an AI proposal, and build a test that could prove you wrong.
Leave with evidence, not a vibe
See what your code verified, where your reasoning held up, and what to practice next.
Signal Replay
Retrace the work.
Find your next move.
A report should help you get better. Follow a finding back to the exact code snapshot, test result, or reasoning checkpoint that supports it.
Inside the methodology01 / CODEThe changeImmutable snapshots
02 / REASONINGThe judgmentCorrectable checkpoints
03 / VERIFICATIONThe evidenceReal execution results
+
YOUR REPORTFacts. Interpretation. Confidence.Unresolved evidence stays unresolved.Bring your curiosity.
Leave with a direction.
Find your next round No trick questions. No typing-speed score.