Senior Full Stack Engineer (React Native /.NET)

Salary: £29,000 - 69,000 per year

Requirements:

• Strong experience delivering customer-facing applications at scale
• Deep expertise in either React Native or .NET/C#
• Strong hands-on experience in the other, able to confidently read, debug and contribute to production code
• Experience delivering features end-to-end across mobile and backend systems
• Clear understanding of how mobile and backend systems interact in a production environment
• Strong understanding of APIs, distributed systems and cloud environments, with AWS preferred
• Experience with CI/CD, automated testing and modern engineering practices
• Ability to contribute to technical discussions and influence implementation decisions
• Experience mentoring engineers and raising engineering standards
• Strong communication and collaboration skills

Responsibilities:

• Take ownership of delivering features end-to-end across the Avios App
• Work across both React Native and .NET/C# to build scalable, reliable solutions
• Contribute meaningfully across the wider stack and collaborate to deliver features holistically
• Work closely with engineers, QA, Product Managers and Designers to break down complex problems and turn them into production-ready solutions
• Bring strong technical judgement and help shape implementation approaches
• Challenge decisions where needed and ensure a high bar for quality, performance and maintainability
• Support the wider team through code reviews and mentoring
• Help continuously improve engineering practices across the platform
• Identify opportunities to improve scalability, reliability and developer experience
• Contribute to a culture of ownership and continuous improvement

Technologies:

• AWS
• Backend
• C#
• CI/CD
• Cloud
• Support
• Mobile
• REST
• React
• React Native
• ASP.NET
• Fullstack

More:

We are IAG Loyalty, one organisation with two ambitious, growing divisions across Loyalty and Holidays. Our Loyalty division is home to Avios, the global loyalty currency, and our Holidays division includes British Airways Holidays and Iberia Vacaciones, connecting customers to destinations worldwide through seamless travel experiences. We are growing and transforming, and this Senior Full Stack Engineer role is based in our London office within our Loyalty division. We offer a hybrid working approach called The Blend, with at least two days per week in the office and the rest from home. We are committed to diversity, inclusion, and creating a workplace where people feel they belong, with opportunities to grow your skills and career.

last updated 34 week of 2026