diagnose

Hard-to-reproduce bugs and unexplained slowdowns can waste hours on fixes that miss the cause. Get an evidence-based diagnosis, with a tested fix when access permits or a clear verification plan when it does not.

What it does

• Investigates failures: Examines available code, logs, traces, tests, and change history.
• Separates facts from guesses: Reports likely causes with confidence levels and supporting evidence.
• Checks performance regressions: Uses measurements and comparisons to narrow down what became slower.
• Fixes and validates: When authorized, tests changes against the reported failure and adds regression coverage where practical.
• Supports read-only reviews: Delivers findings and verification steps without changing the repository or running system.

How it works

1. Describe the failure, expected behavior, and recent changes.
2. Share relevant code or evidence and specify whether changes are allowed.
3. Receive an investigation based on the available access and evidence.
4. Get either a validated fix or a diagnosis report explaining what still needs checking.

Works with

Code repositories, application logs, HTTP services, browser captures, databases, and test tools such as Playwright or Puppeteer, depending on available access.

Why use this skill

It helps avoid speculative patches by checking explanations against observable behavior. Validation covers the original failure, not just an isolated test that happens to pass.

Use cases

• Investigate intermittent checkout errors.
• Trace an API slowdown after deployment.
• Assess a production incident without making changes.

Known limitations

Verified fixes need a safe way to reproduce the failure and permission to make changes. Limited evidence may leave causes unconfirmed.