Senior Full Stack Developer (.NET & React)

Keyloop bridges the gap between dealers, manufacturers, technology suppliers and car buyers.

We empower car dealers and manufacturers to fully embrace digital transformation. How By creating innovative technology that makes selling cars better for our customers, and buying and owning cars better for theirs.

We use cutting-edge technology to link our clients systems, departments and sites. We provide an open technology platform that's shaping the industry for the future. We use data to help clients become more efficient, increase profitability and give more customers an amazing experience. Want to be part of it

The Role:

We're looking for a Senior Full Stack Developer to join our engineering team. You'll own the full product development lifecycle—from API design to UI implementation—working on features that serve our enterprise clients.

Purpose of the role:

• Design and develop complex, enterprise software solutions across our full technology stack (.NET backend, React frontend)
• Build APIs and integrations that connect multiple systems and deliver seamless experiences
• Own code quality through rigorous testing, code reviews, and thoughtful architectural decisions
• Solve complex problems by evaluating requirements, making technology recommendations, and delivering robust solutions
• Mentor and collaborate with junior developers and cross-functional teams to drive innovation
• Lead from the front on incident response and operational excellence, ensuring our platform runs reliably 24/7
• Embrace AI-assisted development using modern tools like Claude and GitHub Copilot to accelerate delivery and explore new possibilities

Core Responsibilities Across the SDLC:

Requirements & Analysis: Collaborate with stakeholders to translate business requirements into technical specifications; evaluate feasibility and propose optimal technical approaches

Design & Architecture: Design scalable solutions with well-defined APIs; create technical documentation; make informed technology choices; review designs with peers for consistency

Development & Implementation: Write clean, production-ready code in C# and React; implement proper error handling and observability; leverage AI coding assistants for productivity

Testing & Quality Assurance: Write comprehensive unit and integration tests (85%+ coverage); conduct peer code reviews; identify edge cases and support QA on bug resolution

Deployment & Release: Participate in release planning; ensure smooth deployments to staging and production; contribute to runbooks; follow security best practices

Operations & Support: Monitor application health; respond to production incidents and perform root cause analysis; identify and address performance bottlenecks; maintain disaster recovery procedures

Continuous Improvement: Identify and resolve technical debt; propose system improvements; mentor junior developers; stay current with emerging technologies

What We're Looking For:

Required Experience

• 4-6 years of professional software development experience
• Backend: Strong proficiency with C#, .NET 6+, .NET Core, ASP.NET MVC/Web API, and Entity Framework
• Frontend: Solid experience building production React applications with JavaScript, Redux, Hooks, and React Context API
• Experience with REST and SOAP APIs, Web Services design, and database architecture (both SQL and NoSQL)
• Hands-on experience with automated testing frameworks (xUnit, nUnit, Jest, Moq, nSubstitute)
• Proficiency with Git/GitHub and modern version control workflows
• Comfortable in Agile/Scrum environments
• Bachelor's degree in Computer Science, Engineering, Mathematics, or equivalent professional experience
• Strong fundamentals in object-oriented design patterns and clean code principles (SOLID, design patterns)
• End-to-end understanding of the full SDLC—from requirements through operations
• Problem-solving mindset—you identify root causes and prevent recurrence, not just fix symptoms
• Quality-first approach—you believe in rigorous testing, code reviews, and thoughtful design
• Attention to detail—you catch edge cases, security issues, and performance concerns before production

AI & Modern Development Skills

• Experience leveraging AI coding assistants (GitHub Copilot, Claude Code, ChatGPT) to improve productivity and code quality
• Ability to effectively prompt and validate AI-generated code
• Understanding of AI capabilities and limitations in software development
• Comfortable experimenting with AI-powered tools for code generation, documentation, testing, and debugging
• Knowledge of secure coding practices when using AI tools (no secrets in prompts, code review remains mandatory)
• Ability to use AI for code analysis and identifying potential bugs or improvements

Nice to Have:

• Experience with microservices and serverless architectures
• Knowledge of system monitoring tools (New Relic, CloudWatch, DataDog, Application Insights)
• Familiarity with API management platforms (Swagger, API Gateway, APIGee)
• AWS experience (Lambda, EC2, RDS, S3, SNS/SQS)
• Understanding of Domain-Driven Design (DDD) or CQRS (Command Query Responsibility Segregation) principles
• Background in the automotive industry
• Experience with containerization (Docker, Kubernetes)
• Knowledge of CI/CD pipelines and infrastructure automation (GitHub Actions, Azure DevOps)
• Experience with AI-powered code analysis tools (SonarQube, GitHub Code Scanning, Copilot for analyzing code quality)
• Understanding of ML/AI integration in applications and AI API consumption
• Experience with performance optimization and profiling tools
• Familiarity with security scanning tools and threat modeling (OWASP)
• Knowledge of database optimization and query performance tuning
• Experience with distributed systems debugging and troubleshooting
• Strong communication skills—you explain technical decisions clearly to engineers and non-technical stakeholders
• Ownership mindset—you take pride in what you ship and support it in production
• Collaborative spirit—you work well with teams and help others improve
• Growth mindset—you stay current with new technologies, tools, and industry trends
• Curiosity about AI—you're interested in exploring how AI can improve development workflows

Why join us

We're on a journey to become market leaders in our space – and with that comes some incredible opportunities. Collaborate and learn from industry experts from all over the globe. Work with game-changing products and services. Get the training and support you need to try new things, adapt to quick changes and explore different paths. Join Keyloop and progress your career, your way.

An inclusive environment to thrive

We're committed to fostering an inclusive work environment. One that respects all dimensions of diversity. We promote an inclusive culture within our business, and we celebrate different employees and lifestyles – not just on key days, but every day.

Be rewarded for your efforts

We believe people should be paid based on their performance so our pay and benefits reflect this and are designed to attract the very best talent. We encourage everyone in our organisation to explore opportunities which enable them to grow their career through investment in their development but equally by working in a culture which fosters support and unbridled collaboration.

Keyloop doesn't require academic qualifications for this position. We select based on experience and potential, not credentials.

We are also an equal opportunity employer committed to building a diverse and inclusive workforce. We value diversity and encourage candidates of all backgrounds to apply.

At Keyloop, AI is a daily ally: We encourage and train every employee to use our AI tools to boost their creativity and productivity.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses and identifying potential inconsistencies or verification signals in application materials based on available information. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.