Senior Full Stack TypeScript Engineer

Senior Fullstack TypeScript Engineer – Fintech London / Remote | B2B | Competitive package Our client is a UK-based fintech company with 25+ years of experience delivering innovative solutions for repo and securities financing markets. Their platform connects major market participants and provides real-time services that enable efficient and accurate trading. We are looking for a Senior Fullstack TypeScript Engineer to join our client’s engineering team. You will work across frontend and backend systems, contributing to scalable architecture, feature delivery, and engineering best practices. This is a hands-on, delivery-focused role with a strong emphasis on system design, quality, and modern engineering practices, including AI-assisted development workflows. Responsibilities • Build and maintain Fullstack applications using TypeScript (Node.js + React) • Design and implement features across frontend and backend systems • Participate in API and system design discussions • Contribute to decisions around REST APIs, authentication, and architecture patterns • Build secure, scalable, and maintainable systems • Work with real-time and event-driven components where applicable • Write and maintain unit, integration, and end-to-end tests • Support production systems and assist in incident resolution when needed • Participate in code reviews and contribute to engineering standards • Use AI-assisted tools (e.g., Cursor, GitHub Copilot) to improve productivity, debugging, testing, and refactoring, while critically validating outputs Requirements • Strong experience with TypeScript, JavaScript (ES6+), Node.js, React • Experience in building fullstack web applications • Solid understanding of REST APIs, authentication, and API design • Knowledge of scalable system design (stateless services, caching, queues, performance) • Experience with relational databases (PostgreSQL / MySQL) • Experience with testing (unit, integration, E2E) • Understanding of performance optimisation and debugging • Ability to evaluate technical trade-offs and system design decisions • Experience working in agile, collaborative teams • Strong communication and ownership mindset • English – professional working proficiency AI & Engineering Mindset • Comfortable using AI tools in daily development work • Able to:• validate AI-generated code for security, maintainability, and performance • use AI for debugging, refactoring, and test generation • critically assess outputs instead of blindly accepting suggestions • Awareness of secure usage of AI tools and data handling practices Nice to have • AWS / cloud experience • Docker / Terraform • Event-driven architecture • GraphQL experience • State management (Redux / Zustand) • Tailwind / Styled Components • Observability (logging, metrics) • Load / performance testing • Data visualization (D3.js)