Senior Front-end Software Engineer ( React, Bazel and Java) *\* YOU MUST LIVE IN THE UK- ALSO SPONSORSHIP IS NOT PROVIDED*\* The organisation manages the test infrastructure and tooling that underpin its client applications. The mission is to provide a reliable, consistent and efficient testing ecosystem that enables engineers to validate their code with confidence and ship high‑quality products. The systems are continually evolving to improve developer experience, reliability and automation through well‑designed services, tooling, documentation and support. The engineering group is migrating its entire client platform application into a Bazel‑based monorepo, so experience in that environment is highly valued. They are looking for a platform‑minded full‑stack engineer with strong data and infrastructure instincts. In this role, you’ll use your curiosity and adaptability to build and improve the test infrastructure that supports all client platforms. This includes web‑focused test frameworks, data pipelines, backend services and internal developer tooling. What You’ll Do Contribute to the ongoing migration to a Bazel‑driven monorepo Shape and drive the technical roadmap for the test infrastructure environment Improve testing practices across the engineering organisation Support engineers to drive test automation and remediate debugging failuresMust Haves Strong in React, Bazel and Java (the three core skills ) Comfortable using AI agents (Claude, Cursor, etc.) to enhance development and tooling Skilled with modern web application test tooling (Mocha, React, WebdriverIO)Preferred Skills Proficient in Java backend services (Apollo + PostgreSQL preferred) Familiar with CI pipelines and infrastructure tooling Experienced with automated testing and scalable test systems Comfortable working across multiple codebases and domains when needed Strong understanding of software architecture and design principles Job Title: Senior Front-end Software Engineer ( React, Bazel And Java ) Location: London, United Kingdom Job Type: Contract Trading as TEKsystems. Allegis Group Limited, Maxis 2, Western Road, Bracknell, RG12 1RT, United Kingdom. No. (phone number removed). Allegis Group Limited operates as an Employment Business and Employment Agency as set out in the Conduct of Employment Agencies and Employment Businesses Regulations 2003. TEKsystems is a company within the Allegis Group network of companies (collectively referred to as "Allegis Group"). Aerotek, Aston Carter, EASi, Talentis Solutions, TEKsystems, Stamford Consultants and The Stamford Group are Allegis Group brands. If you apply, your personal data will be processed as described in the Allegis Group Online Privacy Notice available at (url removed)> To access our Online Privacy Notice, which explains what information we may collect, use, share, and store about you, and describes your rights and choices about this, please go to (url removed)> We are part of a global network of companies and as a result, the personal data you provide will be shared within Allegis Group and transferred and processed outside the UK, Switzerland and European Economic Area subject to the protections described in the Allegis Group Online Privacy Notice. We store personal data in the UK, EEA, Switzerland and the USA. If you would like to exercise your privacy rights, please visit the "Contacting Us" section of our Online Privacy Notice at (url removed)/en-gb/privacy-notices for details on how to contact us. To protect your privacy and security, we may take steps to verify your identity, such as a password and user ID if there is an account associated with your request, or identifying information such as your address or date of birth, before proceeding with your request. If you are resident in the UK, EEA or Switzerland, we will process any access request you make in accordance with our commitments under the UK Data Protection Act, EU-U.S. Privacy Shield or the Swiss-U.S. Privacy Shield