8 min read · telecom provisioning platform, 30M+ subscribers Most companies avoid migrating their monolith for one reason: they imagine it as a single, terrifying event — months of a feature freeze, a weekend cutover, and a rollback plan that's really just hope. That fear is reasonable. A big-bang rewrite of a live system serving 30M+ subscribers really would be terrifying. So we didn't do that. We used a pattern that lets you migrate a monolith one slice at a time, while the system ke...