Crystal in 2026: a 7 MB binary, zero dependencies, and five traps
I spent a few days writing a satellite ground station daemon in Crystal, with an empty dependency list and a hard rule against third-party code. It works, it ships as one file, and it sits at 1.9 MB of memory at rest. This is what the language was like to use, and what it cost. The project is kozai : it reads orbital elements, propagates them with SGP4/SDP4, predicts passes over a ground station, serves a JSON API and an offline web interface, and drives a rotator and a radio through hamlib. About 9,000 lines of source and 6,400 lines of specs, on Crystal 1.21.0. None of that matters here except as the load under which the language was tested — this is a report on the tool, not on the satellites. What the language actually delivers The headline claim of a compiled language with a garbage collector is that you get Ruby's ergonomics and a binary at the end. In 2026 that claim holds, and the numbers are the part worth quoting: Docker image, FROM scratch 7.41 MB Static binary, musl, arm64 6.9 MB Dynamic binary, release 1.9 MB Memory at rest, 2 satellites 1.9 MB Memory at rest, 97 satellites 4.3 MB Memory after a day of serving, 97 satellites 19.3 MB, flat Build steps before crystal build none Runtime files outside the binary none The last two rows are the ones that changed how the project was built. There is no Node in this repository, no bundler, no asset pipeline, and no postinstall . The web interface — HTML, CSS, JavaScript, and a 66 KB SVG of the world's coastlines — is read at compile time by {{ read_file(...) }} and lives inside the executable ( src/assets.cr ). Deploying is scp . The standard library covered the whole surface of a network daemon with six imports: http/server , http/client , json , log , socket , option_parser . That list is not an aspiration; CI fails if a seventh appears. The type system earned its keep in the numerical core. Predicting a week of passes for a hundred satellites is on the order of ten million propagator calls, and the hot loop a