What is the most beautiful / highest quality code you've seen (or written)?

The best system I ever worked with looked incredibly simple. Small, clear functions. Lots of "set a few variables, run some if statements." Incredibly unassuming, humble code. But it handled 10s of millions of transactions per day elegantly and correctly. Every weird edge case or subtle concurrency bug or whatever else you could think of had been squeezed out of the system. Everything fit together like LEGO blocks, seamlessly coming together into a comprehensible, functional, performant system. I loved it. After years of accepting mediocre code as the cost of doing business, seeing this thing in a corporate environment inspired me to fall in love with software again and commit to always doing my best to write high quality code.

EDIT: I think what made that code so good is that there was absolutely nothing unnecessary in the whole system. Every variable, every function, every class was absolutely necessary to deliver the required functionality or to ensure some technical constraint was respected. Everything in that system belonged, and nothing didn't.

Deleted code. Removal of requirements. It's wonderful, letting it go.

It's subjective, but I love what some people come up with in the Code Golf Stackexchange (https://codegolf.stackexchange.com/).

Factor code can be extremely beautiful: y1 y2 [ - sq ] 2map sum n / sqrt It can also be extremely messy.

High quality ("beautiful") code is as simple AND legible as possible, while remaining logically correct. All must be present.

It is a balance. And legibility is a fuzzy attribute that depends on the intellectual capacity of the collective observer.

But, beauty is subjective.. some people think maximally terse code is beautiful so... shrug

It is not open source, but I am still proud of a message delivery system I designed and built alone two years ago. It consists of six independent components and guarantees at least one successful delivery as long as the database remains available. It supports AWS SES, Twilio SMS and MMS, Webhook, Discord messages, and can easily add new providers through an adapter pattern.

Messages are queued through an API, captured by Debezium, produced to Kafka, delivered by workers, logged, and updated through DSNs received via webhook. Failures go to a DLQ where they are retried until the limit is reached.

Each stage runs independently, so any failure only causes minor delay without risking unintended drops. With Prometheus metrics in place, this system has processed more than two hundred thousand messages per day in production for two years without a single reported loss.

Pytudes by Peter Norvig: https://github.com/norvig/pytudes

One recent HN post I loved recently was on Arthur Whitney's insanely terse C code[0]. I personally find it beautiful, and many others did, but many did not. So it goes.

[0]: https://news.ycombinator.com/item?id=45800777

I found the netsurf browser to have a pretty and modular C codebase: https://www.netsurf-browser.org/downloads/source/

To me, Nginx. I remember seeing this file structure and saying: "ohh, that's how it should be done"

    src/os/win32/ngx_alloc.c
    src/os/unix/ngx_alloc.c

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A few years later I stumbled upon this refactoring video by Uncle Bob and that was my second aha! moment.

https://web.archive.org/web/20150905163826/https://www.youtu...

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Many people here recommend Redis as an inspiring example.

My personal best is probably the metaclass tree formation in HumbleDB.

Best I’ve seen is probably the Golang arm64 NEON asm implementation of maphash using AES before the 1.24 update.