Front-End Developer – React or Angular; Front Office & Risk Systems

Front-End Developer – React or Angular (Front Office & Risk Systems)

Join MARGO in the UK (London) –
Permanent & Contracting Opportunity

MARGO is a tech-native consultancy delivering high value-added IT expertise to the financial services industry.

We operate in complex Front Office and Risk environments where user interfaces are critical components of trading, risk and decision-making systems. Our consultants design and build high-performance, real-time and maintainable UI platforms used daily by Front Office, Risk and technology teams.

Joining MARGO means working on technically demanding UI platforms, close to business users, while benefiting from a human-sized structure, strong engineering standards and tailored career paths.

You will work within Front Office and Risk technology environments, contributing to the design and evolution of modern web-based user interfaces.

These platforms typically support:

• real-time trading and monitoring workflows
• risk and P&L visualisation
• analytics and control dashboards
• operational and decision-support tools

The role requires strong ownership of UI architecture, performance and code quality, with close interaction with backend, production and business teams.

We are looking for a Front-End Developer with deep expertise in either React or Angular to work on complex Front Office and Risk UI platforms.

Candidates are expected to be experts in one of the two frameworks.

We are not looking for profiles with superficial exposure to both.

The role is hands‑on, engineering-driven and focused on building scalable, real-time and maintainable front-end applications operating under production and performance constraints.

• Design and develop high‑performance front-end applications using React or Angular
• Own UI architecture, component design and state management
• Build data‑intensive and real‑time user interfaces
• Ensure scalability, maintainability and long‑term evolvability of UI platforms
• Apply best practices around clean code, refactoring and testing

• Develop UIs consuming real-time or near real-time data streams
• Manage high‑frequency UI updates and rendering efficiency
• Optimise performance under real‑time constraints
• Control latency perception, responsiveness and user experience
• Work with event‑driven and streaming data sources

• Work closely with backend teams to define and consume APIs
• Collaborate with production, infrastructure and QA teams
• Translate business and user needs into robust UI solutions
• Act as a technical reference on front‑end topics within the team

• Enforce high standards for code quality, testing and documentation
• Participate in code reviews and architectural discussions
• Contribute to continuous improvement of front‑end practices and tooling
• Support mentoring and knowledge sharing while remaining hands‑on

• React OR Angular (expert level – one is mandatory)
• Type Script and modern Java Script
• State management (Redux, NgRx or equivalent)
• HTML5, CSS3 and modern styling approaches
• Component‑based architecture and modular design

• User interfaces consuming real-time or near real-time data
• High‑frequency UI updates and data refresh mechanisms
• Performance optimisation under real‑time constraints
• Management of rendering efficiency, responsiveness and latency perception
• Interaction with event‑driven and streaming data sources

• Real-time UI patterns (Web Sockets, streaming APIs or equivalent)
• Data grids and complex visual components
• Performance profiling and optimisation techniques
• Modern build tools and frameworks (Vite, Webpack or equivalent)
• Unit and integration testing frameworks

• API-driven architectures
• Authentication and authorisation mechanisms (SSO, JWT, OAuth or similar)
• CI/CD pipelines and version control systems
• Interaction with backend systems and databases

• Strong experience as a Front-End Developer on complex web applications
• Expert‑level…