Django (Celery, Redis)

We're looking for a Sr Backend Engineer with deep Django and real production experience in Celery and Redis, to take full ownership of the core web platform. Concretely: the dashboard backend, the REST API, the async job layer, and the access-control model behind them. Today the lead and the CTO carry this on top of architecture and integrations - that split does not scale, and this role ends it.

You own the application layer end to end. Day to day: you pick up a piece of the platform, design how it should behave, build it in Django/DRF, move the heavy work into Celery tasks, make sure the queue behaves under failure, wire the permission and audit layer around it, cover it with pytest, and ship it. No "someone else will handle the async part". You handle it.

One thing to be clear about: commands issued from this platform reach real industrial equipment in the field. That is why access control and audit logging are must-haves here and not a checkbox - a wrong permission or an unlogged action has consequences outside the database.

What you'll do

• Develop and own the core Django application: dashboard backend, REST API, async job layer, access-control model
• Design and optimize ORM queries - and know what SQL your querysets actually produce
• Write and deploy migrations against live schemas without downtime
• Build and maintain the Celery layer: task design, periodic jobs, retries, idempotency, queue routing
• Design and enforce the role model across API and admin - least privilege, deny by default
• Build audit logging as a tamper-evident trail: who, what, when, from where, with what result
• Write tests as part of the work, not after it

Must have

• 5+ years of production Django. This is the core of the role and the interview goes deep here:
  • ORM at a strong level: query optimization, select_related/prefetch_related, annotations, reading the generated SQL
  • Migrations on live schemas: writing, squashing, deploying without downtime
  • DRF: serializers, viewsets, permissions, versioning API contracts
  • Django internals beyond tutorials: middleware, signals (and when not to use them), custom management commands, admin as a real tool
• 3 years of Celery in production - not "used it once": task design, celery beat, retries and idempotency, queue routing, surviving worker failures without losing or duplicating work
• 3 years of Redis in production - as Celery broker/result backend and as a cache: invalidation strategies, TTLs, locks, and a clear sense of what must never live only in Redis
• RBAC at a strong level: designing role models (dispatcher vs. operator vs. admin) on least privilege, Django groups/permissions, DRF permission classes, object-level permissions, enforcement on both API and admin
• Audit logging: every privileged action and command logged as an evidence-grade trail
• Solid Python fundamentals
• PostgreSQL: indexes, transactions, reading a query plan
• Testing as the norm: pytest, testable code, tests for views/serializers/tasks
• English B1+ - spoken, on technical topics

Nice to have

• FastAPI / Pydantic v2, asyncio
• Docker / Docker Compose, CI pipelines
• TimescaleDB or another time-series store; MongoDB
• OPC UA, Modbus, or other industrial protocols
• drf-spectacular / schema-first OpenAPI workflows
• Exposure to security standards such as IEC 62443 or NIS2 - the audit and access-control requirements originate there