Senior Software Engineer / Data Platform Engineer
Harrington Starr | London Area, United Kingdom (Hybrid – 3 days onsite)Contract Type: 6 month Inside IR35 |
£700–£750 per day
The Role
You will support the evolution of a large-scale financial data platform, modernising legacy enterprise systems while building scalable cloud-based services on AWS. Own SQL Server optimisation, backend service design, and API development in a high-impact platform modernisation initiative.What You'll Do
•Develop and optimise SQL Server queries, stored procedures, and data processing logic•Design and build backend services in Python or C#
•Modernise legacy platforms and improve system performance
•Build and maintain AWS-hosted services and APIs
•Collaborate with distributed engineering and product teams
Top Skills Required
•8+ years professional software engineering experience•Advanced SQL Server expertise (performance tuning, indexing, complex queries) – non-negotiable
•Backend development in Python or C#
•AWS environment experience
•Proven experience in enterprise or legacy systems – critical
•Strong analytical and problem-solving abilities
Nice-to-Haves
•Financial services or market data background•Experience modernising legacy platforms
•API design and ETL/data pipeline experience
•AI-assisted development tools (GitHub Copilot)
•Quantitative or mathematics background
