What I Learned About Caching the Hard Way

We measured first, and the bottleneck was not where anyone expected. The fastest query is the one you never send, but the second fastest has a good index. Logs answer questions you knew to ask; traces answer the ones you did not.

Going further

Caches are easy to add and surprisingly hard to remove. Tests are documentation that fails loudly when it goes stale. Logs answer questions you knew to ask; traces answer the ones you did not. The best architecture diagram is the one the new hire can redraw from memory.

A boring deploy pipeline is a feature, not a lack of ambition. Security is mostly about saying no to defaults that were convenient in 2010.

Details

Caches are easy to add and surprisingly hard to remove. Most production incidents start as a small assumption nobody wrote down. We measured first, and the bottleneck was not where anyone expected. Security is mostly about saying no to defaults that were convenient in 2010.

The rollback plan should exist before the rollout plan is approved. Small pull requests get real reviews, large ones get approvals.

Getting started

The best architecture diagram is the one the new hire can redraw from memory. Most production incidents start as a small assumption nobody wrote down. The fastest query is the one you never send, but the second fastest has a good index. Feature flags are debt with an expiration date you must actually enforce.

Logs answer questions you knew to ask; traces answer the ones you did not. The fastest query is the one you never send, but the second fastest has a good index.

We wrote the migration twice: once to learn, once to ship. Caches are easy to add and surprisingly hard to remove.