Ship the Code, Not the Change
Deploying code and turning on new behavior are two separate decisions that most teams make simultaneously by default. Separating them is what turns an irreversible deploy into a reversible one.
Blog
A Retry Is a Second Request
Retrying a failed operation feels like giving it another chance to succeed. What it actually does is ask a question nobody thought to answer: what happens if the first attempt worked and the failure was just in hearing about it?
Design the Retry, Not Just the Request
Most operations get designed once, for the happy path, and retries get bolted on after as an afterthought. Treating the retry as part of the operation's design from the start closes most of the gaps this thread has described.
Your Retries Are Someone Else's Load
A retry looks like local resilience — my request failed, I'll try again. At scale it's a decision about how much extra load to send a system that may already be struggling, made by every caller independently and at once.
A Cache Is a Promise You Might Break
Every cache makes an implicit promise: this value is still true. The performance win is real, but so is the risk you're quietly signing up for every time you decide not to check.
Cache the Boring Way First
Clever caching strategies solve problems most systems don't have yet, and create ones most systems can't afford. The boring cache — short TTL, simple key, easy to reason about — is usually the right amount of cleverness.
The Cache Key Is the Spec
A cache key is a claim about what makes two requests the same. Get that claim slightly wrong and the cache doesn't fail loudly — it just quietly serves the wrong answer to someone.
Build for Now, Instrument for Later
You can't design for a scale you don't have yet without paying for flexibility you may never use. What you can do is build honestly for today and leave yourself a way to notice the exact moment today stops being enough.
The Assumption That Worked at Ten
Every system is built on assumptions that were true at the scale it was built for. Growth doesn't announce which ones stopped holding — it just quietly waits for you to find out the expensive way.
The Shape Hiding in the Loop
Code that looks like it does one pass over the data can secretly do one pass per item — a hidden multiplication that's invisible at small size and unmissable once the input grows.