Due to an NDA we can’t go into specific business details, but here’s the gist: we inherited a SaaS platform in the accounting and document processing space. The system handled document ingestion, automated data extraction, workflow orchestration, and multi-tenant reporting a fairly typical B2B back-office tool. The original stack was maintained by a team of two backend engineers and one frontend developer. What follows is a breakdown of what the migration to Elixir/Phoenix looked like by the numbers.