Senior Fullstack Developer

About the Role
  
Our Client is seeking a skilled, hands-on Full Stack Developer to join their team and help build and scale the technology behind our platform. This role suits an engineer who enjoys taking full ownership of problems – from design and development through to optimisation and delivery.
You will work across the entire stack to develop and maintain web and mobile applications, improve platform performance, and manage integrations with third-party systems. The ideal candidate is comfortable working in a fast-moving environment where engineers are trusted to tackle complex technical challenges and work closely with end users to continuously refine the product.
  
Key Responsibilities
  
Full Stack Product Development

• Design, build, and maintain end-to-end features across web and mobile applications
• Develop front-end interfaces using React, Next.js, TypeScript, HTML5, and modern CSS frameworks
• Build backend services and APIs using Python and GraphQL to support core functionality and third-party integrations
• Implement scalable data models and application logic to handle complex workflows and large operational datasets

Performance & Scalability

• Improve application performance through optimised query strategies, caching, and state management
• Enhance data transformation pipelines and API responsiveness to ensure reliability at scale
• Identify and resolve performance bottlenecks across both front-end and backend layers

Integrations & Data Architecture

• Design and maintain integrations with external platforms, APIs, and third-party services
• Develop and manage structured data models that support interoperability and complex data relationships
• Contribute to system architecture designed to handle large volumes of operational data

Product Collaboration & User Engagement

• Work directly with internal teams and end users to gather feedback and iterate on platform functionality
• Translate operational challenges and user requirements into practical, scalable technical solutions
• Partner with product and leadership to prioritise development efforts and deliver impactful improvements

Reliability & Risk Controls

• Support the development of systems that maintain platform integrity, including data validation, fraud prevention, and compliance considerations
• Contribute to monitoring, logging, and reliability improvements that ensure consistent system performance

Requirements

• 3–7+ years of experience building and maintaining production-grade applications across the full technology stack
• Strong proficiency in JavaScript or TypeScript and at least one modern front-end framework
• Solid experience developing backend services or APIs using Python or equivalent backend technologies
• Strong understanding of application performance optimisation, caching strategies, and scalable data handling
• Proven experience building or maintaining integrations with third-party platforms or external APIs
• Experience with React Native for mobile application development is advantageous
• Familiarity with structured or schema-driven data models is a plus
• Comfortable working in a fast-paced environment where engineers take full ownership of features from initial design through to deployment