Case Study: CSV Parser Failure on Malformed Quotes
A parser reliability incident that exposed brittle assumptions in CSV ingestion and schema validation.
document
code
performance
Signal
Ingestion workers crashed intermittently on user-provided CSV batches while standard fixtures passed.
Root Cause
Parser configuration assumed strict quoting compliance and lacked a bounded recovery path for malformed rows.
Fix
- Enable tolerant parsing mode with explicit malformed-row handling.
- Capture row-level parse diagnostics for operations review.
- Apply schema validation after safe tokenization, not before.
Regression Guard
Built malformed CSV fixture packs with expected parser outcomes and added crash-resilience assertions to ingestion tests.