Migration

2 articles

Web Engineering • Aug 16, 2026

Zero downtime database migration: 5 flags and a 17x P90 gap

A zero downtime database migration is five feature-flagged phases, not a cutover. P95 said 4x slower, P90 said 17x, and the comparison code took a region down.

12 min read

Web Engineering • May 20, 2025

TailwindCSS v4 Migration Guide: Breaking Changes & the @theme Config

TailwindCSS v4 migration, done right: every breaking change, the new CSS-first @theme config that replaces tailwind.config.js, and a step-by-step upgrade path.

3 min read