// notes on tech

Blog

REST versus WebSockets REST · ask each time Client Server ask, wait, ask again… WebSocket · always open Client Server one connection, both ways
Backend & Data

REST vs WebSockets: letters vs a phone call

Two ways for an app to talk to a server. One is like mailing letters; the other is like keeping a phone line open. Neither is better — they solve different problems.

2026-05-09 · 5 min read
Idempotency keys prevent double charges Client taps twice charge ₹50 · key abc retry · same key abc Server seen key abc? yes → skip the work ₹50 once
Backend & Data

Why clicking Pay twice shouldn't charge you twice

Your payment goes through, the network hiccups, the app retries — and you're charged twice. Idempotency is the idea that doing something twice has the same effect as doing it once.

2026-05-02 · 5 min read
From Dockerfile to running containers Dockerfile the recipe build Image the blueprint run Container Container Container
Infrastructure

Docker, explained without the fear

'It works on my machine' is a joke because it's true — and that's the problem. Docker's whole job is to make 'my machine' travel with the code.

2026-04-25 · 6 min read