SQL Databases
Tables, rows, columns, foreign keys, joins, ACID guarantees. The dominant default in 2026 — and almost always the right starting choice.
NoSQL & Specialized
Document, key-value, search, and vector databases. When and why to reach beyond Postgres.
Choosing a DB
A pragmatic 2026 decision tree for picking your data stores. Spoiler — Postgres almost every time, with Redis added soon after.
Search
How search actually works under the hood — inverted indexes, BM25, tokenization, vector embeddings, ANN, and the 2026 default of hybrid search (BM25 + vector reranking).
Files & media
How to handle file uploads (small + large + resumable), where files actually live (S3, R2, etc.), image processing pipelines, video transcoding + HLS, and the security pitfalls that turn a file feature into a vulnerability.