Systems Engineering
November 3, 2026
8 min
Translating EPUBs with LLMs: a resilient queue, per-chapter retry and cheap models
A book is not a request. It is hundreds of XHTML documents, each taking minutes of inference, and a server that restarts in the middle of the work. The first version of my translator treated the book as a single job: a deploy in the middle of the afternoon was enough to lose hours of translation. The design that survived lives in a small application, with SQLite and one file per book, and solves the three problems that an LLM service has: interruption, validation and cost.
