We are recruiting on behalf of our client for a Senior Software Engineer / Data Platform Engineer to support the ongoing evolution of a large-scale financial data platform. The platform combines long-established enterprise systems and legacy components with modern cloud-based services hosted on AWS. It processes high-volume structured data and supports both internal systems and customer-facing applications. A significant portion of the estate is built on SQL Server, making strong SQL expertise essential. The successful contractor will play a key role in modernising core systems, improving performance and reliability, and enabling scalable next-generation services.
This role is suited to engineers comfortable working across both legacy and modern architectures, with strong experience in backend development and API design.
Key Responsibilities
- Develop, optimise, and maintain SQL Server queries, stored procedures, and data-processing logic
- Improve performance through indexing strategies, query optimisation, and tuning of large datasets
- Design and build backend services using Python or C#
- Support and enhance legacy systems, contributing to incremental modernisation initiatives
- Build and maintain reliable, scalable APIs for internal systems and integrations
- Work with AWS services (including API Gateway) to support cloud-based architectures
- Improve platform reliability through automation, monitoring, and operational enhancements
- Contribute to data processing pipelines, ETL workflows, and system integrations
- Collaborate with engineers, architects, and product teams across distributed environments
- Apply AI-assisted development tools (e.g., GitHub Copilot, IDE AI assistants) within workflows
- Contribute to engineering best practices and continuous platform improvement
- 8 years of professional software engineering experience
- Strong expertise in SQL Server (complex queries, stored procedures, indexing, tuning)
- Experience working with large relational datasets
- Strong backend development experience in Python and/or C#
- Proven experience in AWS environments
- Experience working with complex enterprise or legacy systems
- Strong analytical and problem-solving skills
- API design and development experience
- Experience modernising legacy systems
- Knowledge of data processing pipelines or ETL systems
- Exposure to financial services or market data environments
- Experience using AI-assisted development tools (e.g., GitHub Copilot)
- Strong academic background in Computer Science, Engineering, or related field (or equivalent experience)
