Senior Python Developer, Collections OS

The platform is a multi-tenant FastAPI service with a schema-per-tenant Postgres, Celery workers for everything that takes longer than a second, and a flow engine that parks and resumes a lakh borrower journeys on real-world signals. You will be the senior hand on that codebase: designing the next adapters and node types, keeping the evidence chain and tenant isolation intact, and reviewing the work of the team around you.

• Design and ship backend features end to end: schema and migration, service, route, tests, runbook.
• Extend the flow engine and its park-and-resume contract for new channels, signals and node families.
• Own data integrity: idempotent writes, partitioned tables, the hash-chained audit log, per-tenant isolation.
• Review pull requests for the platform team; set the bar on tests, migrations and observability.
• Carry the on-call rotation with the DevOps engineer and fix root causes, not symptoms.

• Five years of production Python, at least two on FastAPI or a comparable async framework.
• Deep PostgreSQL: transactions, indexing, partitioning, migrations under load.
• Celery or an equivalent job system; Redis; typed Python with mypy in strict mode.
• Has shipped and operated a multi-tenant system; can explain a race condition and how you closed it.

Good to have

• Telephony (SIP, WebRTC), messaging or payment-gateway integrations.
• LiveKit or real-time audio pipelines.
• Indian lending or collections domain knowledge.