Data Platform Engineer
Location: London (Hybrid – 3 days per week onsite)
Contract Type: 6 month Rolling Contract – Inside IR35 (Day Rate)
Rate: £700–£750 per day
About the Role
We are seeking a Senior Software Engineer / Data Platform Engineer to support the ongoing evolution of a large-scale financial data platform.
You'll be working with the technology team, supporting a core platform modernisation initiative.
Our environment combines long-established enterprise systems and legacy components with modern cloud-based services running on AWS. The platform processes high-volume structured financial data and underpins both internal systems and customer-facing products. A substantial portion of the platform is built on large SQL Server data estates, making strong SQL expertise non-negotiable.
You will play a key role in modernising core systems, improving performance and reliability, and delivering scalable services for the next generation of our platform. This role is ideal for engineers who can work confidently across both legacy and modern architectures, and who have deep experience designing and building robust APIs and data services.
Key Responsibilities
- Develop and optimise SQL Server queries, stored procedures, and data processing logic to handle high-volume structured data
- Design and implement backend services using modern programming languages (Python or C#)
- Support and enhance existing legacy platforms, identifying opportunities for iterative modernisation
- Improve query performance through indexing strategies, query optimisation, and data processing efficiency
- Enhance platform reliability through automation, monitoring, and operational improvements
- Build and maintain services deployed within AWS environments, including API Gateway and scalable service architectures
- Design, build, and maintain reliable APIs for internal systems and integrations
- Use AI-assisted development tools (e.g., GitHub Copilot and IDE-integrated AI assistants) as part of the engineering workflow
- Collaborate with engineers, architects, and product teams across distributed locations
- Contribute to engineering standards, best practices, and platform-wide improvements
Essential Skills & Experience
- Significant professional software engineering experience (typically 8+ years)
- Strong SQL Server skills, including complex queries, stored procedures, indexing, and performance tuning
- Experience working with large relational datasets
- Solid backend development experience in Python or C#
- Experience working in AWS environments
- Experience with complex enterprise or legacy systems
- Strong analytical and problem-solving abilities
- Ability to operate autonomously with minimal onboarding in a fast-paced environment
- Excellent communication across technical and non-technical stakeholders
Desirable Experience (not required but if you have 1 or more it helps)
- Experience designing and building APIs
- Strong mathematical or quantitative background
- Experience modernising legacy systems
- Experience designing data processing pipelines or ETL solutions
- Experience using AI-assisted development tools such as GitHub Copilot
- Experience in financial services, market data, or capital markets environments
- Degree in Computer Science, Software Engineering, Electronics, Electrical Engineering, or equivalent experience
- Exposure to regulated industries or complex data governance frameworks
To apply, click the link provided. or email Barry.Ansell@HarringtonStarr.com for a faster response.