Senior AI & Ab Initio Engineer at Vamstar, United Kingdom, £Contractor Rate

Title: Senior AI & Ab Initio Engineer - Fintech AI

Location: UK only | Remote with few days onsite per month

Existing Clients: Large FinTech Company

Type: Full-time Contractor

Core responsibilities & objectives

• Design, build, and migrate Ab Initio workflows to AWS Glue/PySpark.
• Write production-grade, well-tested Python that processes large volumes of data and documents reliably.
• Must have hands-on experience using AI coding tools (e.g., Claude) to generate PySpark / AWS Glue code and build test harnesses
• Own pipeline health: if data is stale, broken, or wrong, it's on you.
• Work autonomously to project deadlines with minimal hand-holding.

Key qualifications & skills (non-negotiable)

• 7+ years in backend data-heavy development or data engineering
• Highly proficient in Python
• Production experience with Ab Initio deployments and cloud migrations
• Hands-on experience with large datasets and high-velocity data streams (Kafka, Flink, Spark).
• Strong with pipeline orchestration tools (Airflow, MLflow, or equivalent).
• Solid SQL skills (Postgres, Redshift, or Snowflake) and NoSQL experience (DynamoDB, OpenSearch, Elastic).
• Real experience with LLM workflows: RAG architectures, embeddings/vector DBs, prompt engineering, function/tool calling, observability.
• Deep understanding of ETL/ELT patterns and data processing at scale.

Preferred background (strong signals)

• Experience with AWS data stack at scale.
• Exposure to financial services industries.
• Built and shipped data, ML and LLM-powered pipelines in production.
• Has debugged a pipeline and knows why observability matters.
• Worked in a fast-moving startup where that's not my job doesn't exist.

Interested? We're a distributed team solving hard problems that will reshape the fintech industry. If you want ownership, not just tickets, we'd like to hear from you.