Senior Software Engineer- Python

Help us use technology to make a big green dent in the universe! Kraken powers some of the most innovative global developments in energy. We create the technology that redefines utilities and unlocks a new energy system of the future. By optimising renewable generation, building a more intelligent grid, and empowering utilities to deliver an exceptional customer experience, our operating system is transforming the industry worldwide. It’s an incredibly exciting time to work in energy. Join us on our mission to improve the lives of ONE BILLION humans within the decade and shape a cleaner, better future for everyone. Humboldt is a subteam of Flex Trading Enablement (Trading Optimisation). We sit at the intersection of commercial energy trading and the green transition, and we own Asset Backed Trading. Asset Backed Trading went live in March 2026. It already runs in two countries, with more markets and features on the way. There is a lot of room to shape how it is built. It models trading, ancillary service allocation, and dispatch for EU portfolios of batteries, solar and wind. We take market and position updates from Flex APIs, allocate energy and services that help stabilise the grid such as FCR and aFRR across the portfolio, and disaggregate those decisions to individual sites. We can both help traders make decisions about how to trade, and disaggregate said trades into per-asset dispatch decisions. This is production software with genuine commercial and operational impact. It not only support key traders' workflows, but also it drives physical asset dispatch and the delivery of grid services, so we care a lot about getting it right. You will work with data scientists and traders to turn prototypes into reliable, well tested services they can trust.

The Role

We’re looking for a Senior Software Engineer to join Humboldt and help shape Asset Backed Trading as it grows into new countries and capabilities. You will work in a Python monorepo of serverless services: event driven pipelines that ingest market and asset data, build optimisation problems, call solvers, and write dispatch and trading positions back out. You will also help evolve the interfaces with other Flex services and APIs that Asset Backed Trading depends on. This is a great role if you enjoy: Owning production systems that have to be correct, not just available Shaping a young service Designing event driven architectures (queues, events, lambdas, APIs) that stay understandable as they grow Turning messy domain rules into clear models, interfaces and tests Working through new problems at the intersection of software architecture and energy systems modelling Pairing with specialists (traders, data scientists, platform) without needing to be an expert in their field on day one Raising the bar across software (typing, testing, observability, tooling, and thoughtful refactors), tooling, and ways of working What you'll do Design, build and operate the Python backend services behind Asset Backed Trading Own event driven flows from trigger to dispatch: queues, lambdas, events, and the Flex API integrations around them Productionise new algorithms and market capabilities, working closely with data scientists so prototypes become reliable services Help with team discovery for new epics, spanning software architecture and energy systems modelling Improve reliability, latency, and operability through testing, monitoring, alarms, and careful refactoring Contribute to infrastructure as code (CDK / CloudFormation) and deployment pipelines Take part in architectural decisions as we grow Asset Backed Trading across EU markets and asset types Support teammates through pairing, reviews, and shared problem solving Help keep a high bar for typed, well tested Python in a domain where silent mistakes are expensive What you'll bring We don’t expect everything, but experience in several of these areas will help. Core skills Strong Python experience Experience building and operating backend services in production Comfort with cloud platforms, ideally AWS (Lambda, API Gateway, SQS, EventBridge, DynamoDB, S3) API design and domain modelling for complex business workflows Writing robust, typed, well tested code (pytest, CI, 100% branch coverage, a real interest in catching bugs before production) Strong communication and collaboration with both engineers and non engineers Judgement in ambiguity: you can make trade offs explicit and keep delivery moving Nice to have / especially relevant Experience in problem solving, modelling, optimisation. Event driven or serverless architectures at meaningful scale Infrastructure as Code (CDK, CloudFormation, or Terraform) Experience with Pydantic, strict typing, and mypy Observability in production (CloudWatch, Grafana) Exposure to energy, trading, optimisation, or other constraint heavy domains Working in a monorepo with shared libraries and multiple deployable services You do not need a background in energy or mathematical optimisation. Curiosity about the domain and a willingness to learn from traders and data scientists matters more than arriving with grid expertise. Our tech stack Backend and services Python 3.13, uv, Pydantic AWS Lambda, API Gateway, SQS, EventBridge, DynamoDB, S3 pytest, mypy, ruff in CI Mixed Integer Linear Programs for expressing energy storage problems (owned with data science; we integrate with the solver) Infrastructure and tooling AWS CDK (TypeScript) and CloudFormation aws-lambda-powertools for observability CI/CD via AWS CodePipeline Grafana dashboards and CloudWatch alarms Product and analysis Databricks SQL, dashboards and notebooks for reporting Jupyter, numpy, pandas, plotly for investigation Cursor, Copilot, and a healthy amount of custom scripting How we work Small, highly collaborative team with high trust and high ownership No blame: we learn from mistakes by improving systems and process, not by finding fault Optimise for impact on users Pair when it helps, work independently