Senior Backend Developer - Architecture, Data Modelling (Apply online only) per day (Inside IR35 - Umbrella)London / Hybrid (3 days per week on-site)Duration: Initially 6 monthsMy client is a global financial services organisation who are hiring an experienced Senior Backend Engineer with strong Architecture and Data modelling skills. The role will focus on making complex enterprise applications faster, simpler and more reliable. This is a backend-focused role, with some frontend capability to deliver changes.Key Requirements:Senior backend engineering experience. A track record of building and operating enterprise-scale web applications, with substantial hands-on responsibility rather than purely architectural oversight.Strong backend and database skills. Production experience with TypeScript/JavaScript and Node.js, API design, asynchronous programming, SQL and relational data modelling.Evidence of performance improvement. Practical experience profiling applications, diagnosing bottlenecks and reducing end-to-end latency, with before-and-after measurements.Architecture and data-model simplification. Examples of reducing complexity in an existing system, recognising redundant data structures and delivering safe, incremental refactoring or migration.Financial services or banking experience requiredFull Stack developers are also consideredNice to have:Snowflake query optimisation and stored procedures; Snowpark Container Services or comparable container platforms; AG Grid and ..... full job details .....