Python/Polygot Engineer (Market Data) - Inside IR35 - Up to £700 Per Day

Senior Full Stack Engineer – Market Data Platforms (Python / gRPC / MongoDB) Hybrid working in London Inside IR35 - Up to £700 per day We are seeking a Senior Full Stack Engineer to develop and enhance market data platforms within a Global Markets environment. You'll build scalable applications across the UI, APIs and data layers, supporting market data analytics, distribution and consumption in a high-performance, business-critical setting. Key Responsibilities • Design, develop and maintain full-stack applications across UI, backend services and data layers. • Build and enhance market data platforms supporting analytics, distribution and data consumption. • Develop high-performance APIs and services using Python, REST and gRPC. • Design and manage large-scale NoSQL data stores (MongoDB, HBase or similar). • Investigate production issues, perform root cause analysis (RCA) and deliver end-to-end resolutions. • Translate business requirements into scalable technical solutions. • Collaborate with Trading, Analytics and Data teams to deliver robust, high-quality solutions. • Drive platform performance, scalability and continuous improvement. Essential Skills • Strong full-stack development experience across frontend, backend APIs and databases. • Excellent Python development skills (polyglot experience beneficial). • Experience building REST and gRPC services. • Hands-on experience with MongoDB, HBase or other NoSQL databases. • Strong debugging, troubleshooting and problem-solving skills. • Experience working with large datasets and data-intensive applications. • Ability to take ownership of issues through to resolution. Preferred Experience • Front Office trading environments (Fixed Income, FX or Derivatives). • Strong understanding of market data, trade lifecycle, pricing and risk. • Experience developing enterprise market data or trading platforms. • Knowledge of market data modelling, instrument reference data or metadata-heavy systems (e.g. FRTB taxonomies). • Experience integrating with downstream analytics platforms and distributed systems. • Exposure to cloud platforms, data streaming or real-time processing technologies. • Previous experience within global banking or financial services. Experience • Approximately 9–15 years' experience (flexible for exceptional candidates).