Senior Full Stack Developer (C# + React)

This job is brought to you by Jobs/Redefined, the UK's leading over-50s age inclusive jobs board.

We are seeking a versatile Senior Full-Stack Engineer to join a high-visibility Flow Modernization initiative within a premier global investment bank. This is a front-office engineering role at the heart of the Equity Derivatives business, focused on rebuilding and modernizing a core Pricing and Booking platform used daily by Traders and Sales teams.

You will play a pivotal role in transitioning a legacy C# desktop suite into a high-performance, real-time ecosystem powered by Python, React, and OpenShift.

Essential functions

• Hybrid Development: Balance high-impact C# engineering on the existing platform with the greenfield rebuild of components in Python and React.
• Modernize Architecture: Transition batch-pricing systems into low-latency, real-time web clients capable of handling complex event-driven workflows.
• Full-Stack Ownership: Develop performant Python backends and modern React/TypeScript frontends that integrate seamlessly with Java-based market data services.
• Performance Engineering: Build scalable, reliable services designed for the high-pressure environment of a global trading floor.

Qualifications

• Strong background in C# engineering is essential for managing the current core application.
• Highly desirable experience building modern web applications, ideally using React and TypeScript.
• A strong willingness (and ideally experience) to pick up Python for backend modernization and event-driven services.
• Familiarity with MongoDB and containerized deployments via OpenShift (or similar).
• Ability to thrive in a globally distributed team (London/US) with frequent context switching between legacy maintenance and new feature development.

Would be a plus

• Experience building backend services using messaging, reactive extensions, or multi-threading for performant streaming analytics.

We offer

• Opportunity to work on bleeding-edge projects
• Work with a highly motivated and dedicated team
• Competitive salary
• Flexible schedule
• Professional development opportunities
• Well-equipped office

About us
Grid Dynamics (NASDAQ: GDYN) is a leading provider of technology consulting, platform and product engineering, AI, and advanced analytics services. Fusing technical vision with business acumen, we solve the most pressing technical challenges and enable positive business outcomes for enterprise companies undergoing business transformation. A key differentiator for Grid Dynamics is our 8 years of experience and leadership in enterprise AI , supported by profound expertise and ongoing investment in data , analytics , cloud & DevOps , application modernization and customer experience . Founded in 2006, Grid Dynamics is headquartered in Silicon Valley with offices across the Americas, Europe, and India.