Go has no versioning, in Rust everything is version 0.1... then one day you update that serialization library from 0.1.4 to 0.1.5 and all hell breaks loose because you didn't notice they changed their data format internally and now your new process can't communicate with the old ones and your integration test missed that because it was running all tests with the new version on your machine. This makes you implement the policy "Only rebuild and ship the full stack" and there you are, scp'ing 1GB of binaries to your server because libleftpad just got updated.