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. This role has a strong backend focus (approximately 60% backend / 40% frontend) and involves working across both 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 Node.js, TypeScript, JavaScript (ES6+), React

• Experience in building full-stack 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)