Engineering essays.
Deep-dives on AI code review, multi-agent architecture, and the craft of shipping reliable software at speed.
August 18, 2026Technical Deep DiveREST Pagination That Returns Inconsistent Page Sizes
Real PR catch: Prisma cursor pagination without `skip: 1` — cursor row duplicates. Skip + take-plus-one fix.
8 min read· Mesrai Team
August 17, 2026Technical Deep DiveGraphQL N+1 Inside a Resolver: How Mesrai Spots DataLoader Gaps
Real PR catch: GraphQL field resolver doing DB lookup per parent — N+1. DataLoader fix.
8 min read· Mesrai Team
August 17, 2026Technical Deep DiveMissing Idempotency-Key on POST: The Stripe-Inspired Catch
Real PR catch: orders-create POST with no idempotency key — retries create duplicates. Header-required + upsert fix.
8 min read· Mesrai Team
August 16, 2026Technical Deep DiveWrong HTTP Status Code on Validation Failure (200 Instead of 400)
Real PR catch: handler returning 200 with `ok: false` on validation error — clients + monitoring see success. 400 fix.
8 min read· Mesrai Team
August 16, 2026Technical Deep DiveOpenAPI Drift: When DTOs Lie About Their Shape
Real PR catch: handler return diverges from OpenAPI spec — client codegen breaks silently. Spec-update + contract-test fix.
8 min read· Mesrai Team
August 15, 2026Technical Deep DiveThe Breaking API Change Mesrai Caught Pre-Merge
Real PR catch: endpoint rename with live mobile callers on old path. Transitional alias + Deprecation header fix.
8 min read· Mesrai Team
August 15, 2026Technical Deep DiveexactOptionalPropertyTypes Bugs Mesrai Catches Across Boundaries
Real PR catch: patch builder mixing `{ name: undefined }` and `{}` semantics — exactOptionalPropertyTypes draws them apart. Build-by-keys fix.
8 min read· Mesrai Team
August 14, 2026Technical Deep DiveObject.keys Type Widening: Mesrai's as const Suggestion
Real PR catch: Object.keys then index access — implicit any error. Object.entries + typed-helper fixes.
8 min read· Mesrai Team
August 14, 2026Technical Deep DiveArray.prototype.includes vs .indexOf on Mixed Types
Real PR catch: number array, string argument — includes always false. Coerce-at-boundary fix.
8 min read· Mesrai Team
August 13, 2026Technical Deep DiveObject Spread Replacing Required Fields: The Type-Holes Mesrai Closes
Real PR catch: spread merge where Partial<T> override has `undefined` — required field becomes undefined. Filter fix.
8 min read· Mesrai Team
August 13, 2026Technical Deep DiveMistyped Generic Constraint: How Mesrai Reads the Inference Path
Real PR catch: pluck with widened input — constraint degrades to any. Parse-at-boundary fix.
8 min read· Mesrai Team
August 12, 2026Technical Deep DiveNon-Null Assertion on Auth Context: The Race-To-Mount Bug
Real PR catch: `user!.name` on async-loaded state — null on first render, runtime TypeError. Skeleton guard fix.
8 min read· Mesrai Team