Senior Full-stack Python Typescript AI Engineer- Outside IR35

ROLE

This position is for a Senior Backend Developer working in python and typescript to support the development on a SaaS product with a focus on Ai.

This role involves designing, building, and optimising scalable backend services and APIs to support a single-tenant, multi‑instance SaaS platform, while contributing to the architecture and implementation of AI‑driven components such as Retrieval‑Augmented Generation (RAG) pipelines, vector databases, semantic search, and structured or knowledge‑graph‑based data modelling approaches. You will support the design of robust data models and pipelines capable of handling both structured and unstructured data with strong traceability and auditability, and help transition prototypes into production‑ready systems with a focus on security, access control, performance, reliability, observability, and monitoring. The role also includes building and managing integrations with external data sources and APIs, collaborating closely with a small, cross‑functional team of developers and stakeholders to refine requirements and deliver iteratively, and contributing to best practices across development standards, testing, and deployment processes.

REQUIREMENTS:

Strong experience as a backend or full-stack developer with a backend focus

Strong proficiency in key scripts, such as Python and TypeScript Proven experience building production-grade SaaS applications Development experience with AI/LLM system architecture, including: RAG pipelines Vector databases (e.g. Pinecone, Weaviate, FAISS, etc.) experience with relational databases (e.g. PostgreSQL) and data modelling Familiarity with API design and integration (REST or GraphQL) experience working with cloud environments (e.g. AWS, Azure, GCP)

Job Title: Senior Full-stack Python Typescript AI Engineer

Location: London, UK

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