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.
Business Context
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.
Role Overview
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.
Key Responsibilities
Front-End Architecture & Development
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
Real-Time & Performance Considerations
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
Collaboration & Integration
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
Quality & Engineering Standards
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
Technical Environment
Core Front-End Technologies
React OR Angular (expert level one is mandatory)
TypeScript and modern JavaScript
State management (Redux NgRx or equivalent)
HTML5 CSS3 and modern styling approaches
Component-based architecture and modular design
Real-Time & Performance Constraints
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
Valued Front-End Exposure
Real-time UI patterns (WebSockets 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
Supporting Technologies (Context)
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
Required Experience & Skills
Essential
Strong experience as a Front-End Developer on complex web applications
Expert-level proficiency in either React or Angular
Solid understanding of front-end architecture and design patterns
Experience building scalable and maintainable UI platforms
Strong attention to performance and user experience
Ability to work in demanding Front Office or Risk environments
Excellent communication and collaboration skills
Valued (but not restrictive)
Exposure to Front Office Risk or real-time systems
Experience working on data-intensive or analytical UIs
Familiarity with real-time communication patterns
Mentoring or technical leadership experience
Why Join MARGO
Access to complex Front Office and Risk UI platforms
Strong emphasis on engineering quality and clean front-end architecture
Real-time performance-sensitive UI challenges
Human-sized consultancy with close support and long-term focus
Long-term career opportunities across engineering and architecture