#Backend Engineering

Migrating Production Auth Without Breaking the Product

A four-phase migration from local JWT to Supabase Auth with reversible migrations, additive verification, and 82 integration tests passing throughout.

September 9, 2026 5 min read

Making a Personal-Finance API Trustworthy: Tests, Isolation, and Balance Accounting

How to build an API that guarantees correct account balances, strict user isolation, and consistent analytics through isolated integration tests, immutable transaction rules, and cache invalidation.

September 8, 2026 5 min read