engineering
Foreign keys get the attention but they are only one of several constraint types that databases enforce. CHECK constraints encode invariants directly into the schema. EXCLUDE constraints handle the cases where uniqueness is conditional or interval-based. Both are underused, and both repay
engineering
Every system that stores events accumulates them faster than the team expects. The retention question is not just how long to keep events but which events, what to keep about them, and how to age the storage so the recent events stay fast to query while the old events stay cheap to keep.
engineering
Foreign keys enforce referential integrity at the database layer, which means the rule holds regardless of which application writes to the table. The trade-offs come from the constraint check itself, the lock granularity it requires, and the cascade options that look helpful but often crea
engineering
Job queues with priorities sound straightforward. The naive implementation works fine until a flood of high-priority jobs causes low-priority jobs to wait indefinitely. The patterns that survive production traffic share a structural property: priority changes which queue runs next, not whi
engineering
PostgreSQL does not update rows in place. Every UPDATE writes a new row version and leaves the old one behind, and VACUUM is the background process that cleans up. Most teams discover this when autovacuum falls behind and the database starts getting slower without an obvious cause.
engineering
Every HTTP request that opens a new TCP connection pays for the three-way handshake plus the TLS handshake, which on a typical internet path is 100-200 milliseconds. Keep-alive amortizes that cost across many requests on the same connection, but only if every layer of your stack actually r
engineering
The choice of primary-key strategy is one of the earliest schema decisions and one of the hardest to reverse. Auto-increment integers, UUIDs, ULIDs, and Snowflake-style IDs each have specific structural costs and benefits that compound across the lifetime of the system.
engineering
Tests that hit real third-party APIs are flaky and slow. Tests that mock them by hand drift from reality and miss real bugs. The patterns that work in between are fixture-based recording, contract testing against the vendor's spec, and a small set of disciplines that keep the mocks honest.
engineering
Savepoints let you roll back part of a transaction without losing the work that came before. Most application code never uses them; the patterns where they earn their cost cover bulk operations, optimistic flows, and per-item retry within a larger unit of work.
engineering
Schema-first puts the OpenAPI document at the center and generates server stubs and client SDKs from it. Code-first writes the server in your favorite framework and generates the spec from annotations. The right answer depends on who reads the spec and how often it changes.
history
Before railways, before paved roads, the canal was the artery of the early industrial economy. The engineering required to move water uphill against gravity through systems of locks, aqueducts, and tunnels is among the most underappreciated achievements of the 18th and 19th centuries.
engineering
Most engineering teams build their transactional email pipeline once, send a few thousand messages, and assume the system works because no one is complaining. They learn the truth six months later, when a customer reports that they have not received any emails from the product in two weeks, or when