Lens — What Went Wrong
Something broke. Find the pattern.
Real-world failures organized by pattern, not by tool or timeline. Each incident is dissected: what was observed, what was misleading, what the root cause was, and what foundational force made it possible.
Silent Correctness Failures
Pipeline succeeded, data is wrong. Duplicates, silent type coercions, join fanouts, null drops — the bugs no alert catches.
Contract & Schema Violations
Schema drift, incompatible changes, partial migrations, and broken contracts between producers and consumers.
Performance Failures
Technically correct but unusably slow. Skew, poor execution plans, hidden bottlenecks, and the gap between 'ran' and 'ran well.'
Cost Overruns
Worked exactly as designed, generated an unsustainable bill. Full scans, unnecessary recomputation, invisible cost drivers.
Stateful Processing Failures
Stale checkpoints, double-counted aggregates, state corruption — the failures that only appear when distributed state meets time.
Reprocessing Failures
Running historical data through a live system. Duplicate writes, state conflicts, and the correctness assumptions that only break when you go back.