Sr Python Engineer

We're looking for a Senior Python Engineer to become the technical owner of the backend platform: you decide how it is built.
The MVP is live and it proved the product works. Now it has to become a platform that holds under load, over unreliable networks, on a 24/7 production system - which means new services designed properly, an engineering standard that does not exist yet (Spec-Driven Development, AI-powered pipelines, CI/CD, review), and the old shortcuts retired along the way.

What you'll do
Take full ownership of the backend: Django, DRF, FastAPI services, Celery, PostgreSQL, TimescaleDB, Redis, and the OPC UA components
Audit the existing MVP end to end and define the refactoring strategy.
Design reliable failover for site connectivity so telemetry and commands keep working over unstable networks
Balance fast product validation against long-term platform stability, and re-prioritize when the business shifts
Build AI-powered engineering workflows (agentic pipelines) and make Spec-Driven Development the standard
Work with cybersecurity specialists on IEC 62443 and translate its requirements into platform architecture
Set the engineering standards: code quality, reviews, CI/CD, testing, API stability

Must have
6+ years of commercial Python, with strong production experience across: Django and DRF, FastAPI (Pydantic v2), Celery, PostgreSQL, Redis, Docker / Docker Compose, pytest and CI/CD
System design, hands-on: you have defined service boundaries, API contracts, data flows and scalable architectures for production - and can walk through decisions you made and what they cost
Authorization models by design: RBAC, least privilege, Django/DRF permission systems, object-level permissions, and consistent enforcement across distributed services
Resilient third-party integrations: retries with exponential backoff, rate-limit handling, Redis caching and invalidation strategies, graceful degradation when an upstream service goes down
OPC UA - working knowledge: client/server model, namespaces, subscriptions, security modes
AI-driven engineering: contract-first / Spec-Driven Development (OpenAPI/Swagger, Pydantic, gRPC), plus experience building or using agentic pipelines - CrewAI, LangGraph, or your own orchestration - to automate code generation, tests, documentation, review or integration validation
English B2+

Nice to have
Modbus TCP/RTU or other industrial protocols
IEC 62443 / OT security
TimescaleDB, InfluxDB or ClickHouse; MongoDB
Redis beyond simple caching
Observability: Sentry, Flower, structured logging
Refactoring legacy production systems without downtime