Senior Python Backend Engineer

Senior Python Engineer | Stockholm Location: Stockholm, Sweden | Hybrid Type: Permanent, full-time Salary: Competitive, depending on experience About the company A well-funded Stockholm tech startup building software that helps businesses get more out of their data. The founders have scaled products at some of the Nordics’ best-known tech companies, and they’re now building a product team that wants ownership, not just tickets. The team is small, so your work is visible and your voice carries weight. About the role You’ll join a small engineering team as a senior backend engineer, working on the systems at the core of the product. You’ll own features end to end, from the first design conversation through to deployment and monitoring in production. You’ll work day to day with backend, data and ML engineers, and help set the technical direction as the team grows. What you’ll do

• Design, build and scale APIs and services that run in production
• Make architecture decisions and write them up so the team can build on them
• Build and maintain data pipelines that handle large volumes of data
• Take features from design to deployment, monitoring and iteration
• Build AI-driven features from prototype to production, including LLM integrations, RAG pipelines and agentic workflows
• Set up evaluation, guardrails and cost and latency monitoring so AI features stay reliable once they’re live
• Use AI coding assistants as part of your daily workflow, and help shape how the team uses them well
• Improve performance, reliability and observability across the platform
• Lead code reviews, mentor engineers and share knowledge across the team

Tech you’ll work with You don’t need all of this. We care more about how you think than about a perfect keyword match.

• Python: FastAPI, Django, Flask, Pydantic, SQLAlchemy, Celery, asyncio, pytest
• Cloud and infrastructure: AWS/GCP/Azure (Lambda, RDS, S3, SQS/SNS), Docker, Kubernetes, Terraform, CI/CD
• Data: Kafka, Spark, Airflow, dbt, Snowflake or BigQuery, PostgreSQL, Redis
• AI and ML: LLM APIs (OpenAI, Anthropic, open-source models), RAG, vector databases, LangChain or LlamaIndex, tool use and agent frameworks, MCP, PyTorch, MLOps
• AI-assisted development: Claude Code, GitHub Copilot, Cursor
• Observability: OpenTelemetry, Grafana, Datadog or similar
• Integrations: REST, GraphQL, gRPC, MQTT and event-driven architectures

About you

• 6+ years of backend engineering experience, with Python as your main language
• You’ve designed, shipped and maintained production systems, and you’ve owned them when they broke
• You’ve made architecture calls and can explain the trade-offs
• You like digging into the “why” behind a problem, not only the “how”
• You write clean, tested, maintainable code and care about reliability
• You’ve mentored other engineers or acted as an informal tech lead
• You’re comfortable in a small team and happy to take ownership
• You communicate clearly with engineers, data teams and non-technical colleagues

Nice to have

• Hands-on experience building with LLMs, or putting ML models into production
• Experience building agents or multi-step LLM workflows, and measuring how well they work
• Large-scale data processing or streaming experience
• Event-driven or IoT-style architectures
• Startup or scale-up experience
• Front-end skills (React and TypeScript)
• Familiarity with another typed backend language such as Go, Rust or Java

What we’re really looking for The right mindset. If you have strong engineering fundamentals, you’re curious, and you want to become a core part of the team, we’d like to hear from you, even if you don’t tick every box. What’s on offer

• A senior role with real ownership and influence on the product
• A well-funded company with experienced founders
• A small, collaborative team in Stockholm
• Room to work on AI features properly, with time to build them well

Next steps Interested, or know someone who should be? Apply below for a confidential chat. All conversations are handled in confidence. CVs are required before we can talk.