Quality regression: trial-and-error debugging instead of root-cause diagnosis

Summary

Long-time daily user reporting a noticeable quality drop over the past month. Tasks that used to be handled sharply in one pass now take 3-4 attempts with circular fixes.

Specific patterns observed

1. Trial-and-error instead of diagnosis — When debugging a backend issue, Claude made 3 sequential code changes (each breaking something new) instead of reading the error logs first. The logs clearly showed the root cause (a 400 error with a specific message), but Claude guessed at solutions instead of reading them.

1. Over-engineering simple fixes — A simple API endpoint 404 fix (wrong URL path) got correct, but subsequent issues got layers of abstraction added (sanitization layers, detection systems, state machines) when the root cause was a single config value.

1. Not learning within a session — After fix A broke thing B, and fix B broke thing C, Claude didn't step back to re-evaluate the approach. It kept patching forward instead of understanding the system holistically.

1. Circular fixes — Changed a routing config to use Provider A (fast but limited), then reverted to Provider B (powerful but slow), then tried to tune Provider B's timeouts — when the real issue was Provider B returning errors due to corrupted input data.

What "good" looked like (a month ago)

• Read the error/logs FIRST, identify root cause, make ONE targeted fix
• Understand the system before changing it
• Simple problems got simple solutions, not frameworks

Environment

• Claude Code CLI (Opus model)
• Complex full-stack project (FastAPI + Next.js)
• Daily professional use for ~2 months

Impact

This user is actively evaluating competitor tools because of the regression. The quality drop is costing real productivity — tasks that should take 10 minutes are taking hours.

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Filed on behalf of a user via Claude Code's conversation. No project-specific code, credentials, or business information is included.