Senior Software Engineer — Python / Infrastructure
About the role
You'll be building the Python services behind our smart meter platform: the ingestion path that handles MQTT traffic from thousands of deployed devices, the APIs that expose that data, and the internal services that keep it all consistent. Thousands of live meters depend on this working, so correctness and observability matter more here than shipping fast.
You deploy what you write and you own it once it's live. The platform runs on a Kubernetes cluster that's stable in production — uptime is typically measured in months, and periodic cluster patching is the main source of downtime. There's no on-call rota. In practice, operations is an occasional afternoon rather than a firefighting habit, and the overwhelming majority of your time goes into writing code.
What we're looking for
- 5+ years writing production Python, with a track record of owning services rather than contributing to them
- Strong design instincts for backend services: APIs (FastAPI, Flask or similar), async work, data modelling, testing, and handling failure in message-driven systems
- Comfortable in Linux and with Docker; able to deploy your own work to Kubernetes and debug it when it misbehaves
- Working knowledge of AWS (EC2, DynamoDB, IoT Core or equivalents)
- Comfortable owning a service in production end to end — deploying it, knowing when it's unhealthy, and being the person who works out what went wrong
- Able to debug across boundaries: You can work out whether it's the device, the broker, the network, or your code
- Sound judgement working autonomously — you'll often be making calls on your own
Nice to have
- MQTT or other message brokers, and experience with unreliable or intermittently connected clients
- Time-series data at volume
- Embedded, telemetry, or energy-sector experience
- Profiling and performance work in Python
Process
- CV review
- A 30-minute call
- A Python exercise based on a realistic message stream, then a conversation about it covering service design and how you'd run and monitor what you've built
Practical details
- Hybrid working, with regular on-site presence for team collaboration.
- Small team of experienced engineers and supportive managers — not a ticket factory.
- Right to work: You must already have the right to work in the UK. We are not able to offer visa sponsorship or a Certificate of Sponsorship for this role, and applications requiring sponsorship can't be progressed.
