Graph queries for a social feed
Why a graph database was the only sane choice for a social feed where the interesting question isn't what your friends posted, but what your friends' friends are doing this Saturday.
Node
2015
2014
The middleware chain
Two people, one Express app, and eight middleware functions between the request and the response.
Node.js on a Raspberry Pi
Running a custom Node.js blog engine on a Raspberry Pi at home -- from a 45-day wait and a dead board to DuckDNS, ISP port blocking, and the first external request.
2013
Express middleware chains
Route handlers don't need to be nested callbacks -- Express middleware chains turn them into a flat, readable sequence.
Sorting by multiple fields
A composable predicate function for sorting arrays of objects by multiple fields -- with reverse, primers, and short-circuit evaluation.
2012
A fifty-line rate limiter
In-memory rate limiting as Express middleware. No Redis, no external service. Fifty lines, one file.
Connection pooling
The Node.js MySQL driver doesn't pool connections. Under load, you run out. Fifty lines with generic-pool fixes it.
URL mapping in Redis
Loading every product, category, and brand URL into a Redis hash at startup, and a middleware that rewrites requests before Express sees them.