Senior Web Application Developer

Insight Global are seeking a Senior Web Application Developer for a leading global financial markets and trading infrastructure organisation. This is an exciting opportunity to join a high-performing engineering team responsible for building and maintaining business-critical web applications that deliver market data and support trading services used by market participants worldwide. You will work across the full web technology stack, contributing to the design, development, testing, deployment, and ongoing enhancement of complex, high-availability platforms. This is a permanent, full-time position that requires 4 days onsite in London, UK. The successful candidate will play a key role in delivering scalable web solutions, collaborating with stakeholders, mentoring engineers, supporting production environments, and helping drive best practices across software development, testing, and automation. Must-Have Requirements Include: Strong experience developing high-performance, data-driven web applicationsExperience with Python and React developmentStrong knowledge of JavaScript, including modern frameworks such as ReactExperience with Django or other MVC web frameworksExperience building full-stack web solutions, including frontend, backend APIs, and database integrationStrong knowledge of HTML5 and CSS3Experience working with Linux or UNIX-based systemsExperience with SQL databases, particularly PostgreSQL or similar technologiesExperience implementing automated testing, including unit testing and full-stack web testingAbility to participate in code reviews, technical documentation, and requirements gathering activitiesStrong communication skills with the ability to collaborate across technical and business teams Key Responsibilities: Design, develop, enhance, and maintain web-based software platformsBuild end-to-end solutions covering frontend interfaces, backend services, APIs, and database functionalityCreate and maintain technical documentation and customer-facing materialsImplement robust automated testing and support quality assurance initiativesParticipate in sprint planning, requirements gathering, and peer code reviewsSupport production deployments and troubleshoot issues as requiredCollaborate with cross-functional stakeholders to deliver technical solutions on scheduleMentor team members and contribute to engineering best practicesSupport business-critical systems and participate in occasional out-of-hours testing and operational activities