Senior Software Engineer- Python

• 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

• 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

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.

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

• 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 when it does not

• Sustainable pace

• Ship quickly without dropping quality: small PRs, fast iteration, quality built in from the start

Are you ready for a career with us? We want to ensure you have the right tools and environment to unleash your potential. If you have any accommodation requests, please contact us at ----- We’ll do our best to tailor the experience to your needs so you can feel comfortable, confident and be at your best! Studies have shown that some groups of people, like women, are less likely to apply to a role unless they meet 100% of the job requirements. Whoever you are, if you like one of our jobs, we encourage you to apply as you might just be the candidate we’re looking for! At Kraken, we're creating a team of genuine, honest, empathetic people. Our people are our strongest asset and the unique skills and perspectives people bring to the team are the driving force of our success. As an equal opportunity employer, we do not discriminate on the basis of any protected attribute. We consider all applicants without regard to race, colour, religion, national origin, age, sex, gender identity or expression, sexual orientation, marital or veteran status, disability, or any other legally protected status. Our (i) Applicant and Candidate Privacy Notice and Artificial Intelligence (AI) Notice , (ii) Website Privacy Notice and (iii) Cookie Notice govern the collection and use of your personal data in connection with your application and use of our website. These policies explain how we handle your data and outline your rights under applicable laws, including, but not limited to, the General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA). Depending on your location, you may have the right to access, correct, or delete your information, object to processing, or withdraw consent. By applying, you acknowledge that you’ve read, understood and consent to these terms Please note that, in line with our current recruitment policy, we are unable to offer visa sponsorship for this position; applicants must have the right to work in the country that they're applying to, at the time of application. Find more English Speaking Jobs in United Kingdom on Arbeitnow