Build the engine every ZAAN product runs on: the services that ingest Word and PDF files, understand their structure clause by clause, compute redlines and keep a perfect audit log. 2.4 million contracts have passed through it; the next ten million should feel just as instant.

What you will do

• Design services that parse DOCX (OOXML) and PDF into a faithful clause tree: numbering, cross-references, defined terms, tracked changes and comments.
• Build the redline and diff engine that turns a model's suggestion into a clean tracked change a lawyer can accept in Word.
• Own APIs, queues and storage for matters, playbooks and precedent search, with tenant isolation and region pinning.
• Make the platform observable and fast: tracing, load tests, p99 budgets per document size.
• Review code, mentor engineers and write the design docs others build on.

What you bring

• 7+ years of backend engineering, with ownership of high-availability services in production.
• Deep experience in Python or Go (we use both) plus PostgreSQL; comfort with event-driven systems and object storage.
• Experience with complex document formats, compilers or parsers, or anything where correctness is measured to the character.
• Strong system design and clear written communication in English; Mandarin is a plus for the Shenzhen team.

Nice to have

• Rust for performance-critical paths, OOXML internals, search engines (OpenSearch, pgvector), multi-tenant SaaS with regional data residency.

How we hire

A 10-minute AI interview in English (you are told up front that you are speaking with an AI), a conversation with the team you would join, and a short paid practical task that mirrors real work. We aim to decide within three weeks.