But It Works on My Machine

The four most cursed words in software: “works on my machine.” It is technically true, completely useless, and the documented alibi of a thousand bugs that went on to have rich careers in production.

Your machine has eleven undocumented environment variables, a config file you edited in 2019 and forgot about, a globally installed dependency from a project that no longer exists, and possibly a moon phase that happens to align. The production server enjoys none of these private blessings.

This, in the end, is why we invented containers — not for elegance, but so that “my machine” and “your machine” could finally be the exact same cursed machine, failing identically for everyone. We did not fix the problem. We just made it fair. That is progress.