Python Developer in London

Senior Python Developer / Backend Software Engineer (Python, Data, AWS) | London / Remote | Up to £90,000
About The Company
Client Server is representing a scaling fintech that is transforming how large industrial and commercial organisations buy energy. The company has developed a complex, real-time energy trading platform designed to make energy procurement more accessible, transparent and effective. Its technology supports demanding trading, billing and analytics operations, bringing together complex energy systems and digital services in one platform.
About The Role
As a Senior Python Developer, you will design, build and improve the backend services that support the platform’s trading, billing and analytics capabilities. This is a hands-on engineering role for someone who can combine strong Python development with practical data engineering experience. You will help create resilient, modular services and reliable data flows across PostgreSQL, Amazon Redshift, analytics layers and APIs.
You will contribute throughout the software development lifecycle, from understanding requirements and shaping technical approaches to implementation, testing, deployment and ongoing improvement. The role also involves working with data-rich systems and event-driven architectures, ensuring that services and pipelines can support complex, high-throughput use cases. You will have input into technical discussions and decisions, while helping the team maintain a high standard of software quality as the business scales.
Qualifications
You bring substantial software engineering experience across the full development lifecycle and strong hands-on expertise building backend systems with Python. You have designed or maintained REST APIs and microservices, and understand how to develop reliable, maintainable services in a production environment.
You have a good working knowledge of AWS, including Amazon Redshift, and experience with PostgreSQL and data engineering practices. Relevant experience may include building data pipelines and ETL processes, developing data models, and working with dbt or comparable tools. You understand event-driven systems and are comfortable reasoning about data flows across services and analytical platforms.
Experience in fintech, payments, eCommerce or another high-throughput, data-intensive environment would be valuable. Familiarity with large language models and agentic programming is also relevant. Alongside your technical strengths, you communicate clearly, collaborate effectively and can contribute constructively to engineering discussions. Applicants must be based in the UK and have the right to work in the UK.
Responsibilities
Build, enhance and support backend services using Python, applying sound engineering practices to deliver readable, testable and maintainable software. Design and develop REST APIs and microservices that support trading, billing and analytics workflows. Create and improve data models, pipelines and ETL processes connecting PostgreSQL, Redshift, analytics layers and platform APIs.
Help ensure data flows and services are resilient, dependable and appropriate for complex, real-time use cases. Contribute to technical design, architecture discussions and implementation decisions. Work collaboratively with colleagues to understand product needs, solve challenging engineering problems, and deliver improvements across the platform. Participate across the development lifecycle, including testing, deployment and ongoing system refinement.
Benefits
The role offers a salary of up to £90,000, alongside a remote-first working arrangement for UK-based employees. You can work from home full time, with approximately quarterly visits to the London team paid for by the company. You will take on meaningful technical challenges, contribute to an ambitious fintech product and have opportunities to develop your career as the business grows.
Equal Opportunity
Client Server and its client are committed to fair and inclusive recruitment. Applications are welcomed from qualified candidates regardless of background or identity. Selection is based on relevant skills, experience and the ability to contribute to the role. Applicants must meet the stated UK location and right-to-work requirements.