Senior Full stack developer

Kofeko; Test Valley; On-site; GBP 60,000 - 90,000; Full time

Job summary

Kofeko in the United Kingdom is seeking a Senior Full Stack Developer to build and maintain end-to-end features across .Net backend, React frontend, and Python helpers where needed.

You will own design and delivery of robust software, collaborating across teams, and ensuring reliable database integration while delivering maintainable code and high-quality user experiences. This on-site role requires hands-on coding, refactoring for maintainability, and proactive troubleshooting to reduce defects.

Qualifications

• 5+ years in a full-stack development role.
• Strong .Net backend development capability.
• Proficient with React and JavaScript for frontend, and Python when needed.

Responsibilities

• Designing and implementing full-stack features, from backend logic to frontend user experience.
• Backend development using .Net, including API and service implementation.
• Frontend development using React and JavaScript, translating requirements into working UI components.
• Python development tasks where required (supporting services, scripts, or integrations).
• Database integration work, including implementing, updating, and troubleshooting application-to-database interactions.
• Diagnosing and resolving defects across the stack, across frontend, backend, and database layers.
• Improving code structure and maintainability as part of ongoing feature development and change work.

Skills

.Net development

React

JavaScript

Python

Database integration

On-site work

Full-stack delivery

Tools

Git

API design

Job description

Role Overview

As a Senior Full stack developer, you will build and maintain end-to-end software features across backend services, APIs, and user-facing web interfaces. You will work hands-on across the stack, with a strong focus on delivery quality, maintainability, and reliable database integration.

ROLE DETAILS

• Work arrangement: On-site
• Employment type: Full-time

Role Overview

As a Senior Full stack developer, you will build and maintain end-to-end software features across backend services, APIs, and user-facing web interfaces. You will work hands-on across the stack, with a strong focus on delivery quality, maintainability, and reliable database integration.

WHY THIS ROLE EXISTS

This role exists to deliver and evolve full-stack application functionality that depends on .Net-based backend development, React and JavaScript for the frontend, Python where needed, and solid database integration. The goal is to ensure features are implemented correctly across layers and can be maintained and extended over time.

What You Will Own

• Designing and implementing full-stack features, from backend logic to frontend user experience.
• Backend development using .Net, including API and service implementation.
• Frontend development using React and JavaScript, translating requirements into working UI components.
• Python development tasks where required (e.g., supporting services, scripts, or integrations).
• Database integration work, including implementing, updating, and troubleshooting application-to-database interactions.
• Diagnosing and resolving defects across the stack, including issues spanning frontend, backend, and database layers.
• Improving code structure and maintainability as part of ongoing feature development and change work.

What Success Looks Like

• Full-stack features are delivered end-to-end, working correctly across UI, backend, and database integration points.
• Backend and frontend codebases remain stable and maintainable as functionality grows.
• Database integrations are reliable, and data-related defects are identified and resolved efficiently.
• Issues are troubleshot effectively across layers, with clear fixes that reduce repeat problems.

Must-have Capabilities

• At least 5 years of professional experience in a full-stack development role.
• Strong .Net development capability.
• Strong React and JavaScript development capability.
• Python development capability.
• Hands-on experience with database integration (implementing and troubleshooting application-to-database interactions).
• Ability to work effectively on-site in a full-time role.