Senior Full-Stack Engineer

We’re IAG Loyalty - one organisation with two ambitious, growing divisions across Loyalty and Holidays. Each has its own goals, strategy and team, but together we’re united by a shared vision to create a more rewarding world of travel and experiences.

Our Loyalty division is home to Avios, the global loyalty currency, enabling millions of members to collect and spend rewards across travel, retail and financial services. Our Holidays division including British Airways Holidays and Iberia Vacaciones, brings together trusted brands, connecting customers to thousands of destinations worldwide through seamless, end-to-end travel experiences. We’re on an exciting journey of growth and transformation – we’re going places.

Join IAG Loyalty and help shape the continued development of the Avios App, a global loyalty platform used by millions of travellers worldwide. As a Senior Full Stack Engineer, you’ll own the delivery of complex, high-impact features that enhance the mobile experience across the Avios ecosystem. Working within a dedicated mobile product team, you’ll design and build end-to-end solutions across React Native, .NET/C#, and AWS, bringing strong technical judgement and helping guide implementation approaches within the team. You’ll be part of a modern, agile engineering environment where collaboration, curiosity, and continuous improvement are encouraged. This is a chance to work on a high-traffic consumer application with real impact, supporting a platform that connects with major airline partners including British Airways, Iberia, and Aer Lingus, while mentoring other engineers and contributing to a strong engineering culture.

You’ll play a key role in designing and delivering new features and improvements for the Avios App, working across both mobile and backend technologies to build scalable, reliable solutions used by millions of customers. As part of a collaborative, agile product team, you’ll take ownership of end-to-end feature delivery using React Native and .NET/C#, contributing hands-on code while ensuring high standards of performance, reliability, and maintainability across the platform. Working closely with engineers, QA, product managers, and designers, you’ll help shape technical solutions, break down complex problems, and drive delivery across the platform. You’ll also contribute to code reviews, technical discussions, and best practices within the team, while mentoring and supporting other engineers to help raise the overall quality of the codebase. You’ll also contribute to improving engineering practices, identifying opportunities to enhance performance, scalability, and developer experience across the platform.

What we need from you:

• Strong commercial experience as a Full Stack Engineer delivering complex customer-facing applications.
• Hands-on experience with React Native.
• Strong development experience in .NET and C#, building scalable APIs and services.
• Experience working with AWS, ideally including serverless technologies.
• Good knowledge of modern engineering practices such as CI/CD, automated testing, and clean code.
• Experience delivering features in agile, collaborative teams.
• Ability to troubleshoot and solve problems across distributed systems.
• Experience with RESTful APIs, microservices, and event-driven architectures.
• Strong communication skills and a collaborative mindset.
• Experience mentoring engineers and contributing to technical discussions and solution design.
• Interest in building mobile products at scale used by millions of customers.

We might not be right for you if:

• You only want to focus on your to-do list; we’re a small, high-performing team, we help each other to succeed.
• You value perfection over fast iteration and progress; IAG Loyalty moves fast, we learn and iterate as we go; our environment isn’t right for everyone.
• You’re looking to create but not build; this is an end-to-end role, you need to be comfortable owning your space, from ideation through to delivery and review.

If you think you have what it takes but don't meet every single point above, please do still apply. We’d love to chat and see if you could be a great fit.

This role will work as part of our Loyalty Division and is based out of our London office. We call our approach to hybrid working The Blend — it’s about giving you the flexibility to choose where you do your best work, while staying connected with your team and the wider business. This means you will be required to spend at least two days per week in the office, with the rest of the time working from home. You may also be required to work from one of our other office or partner locations, based on your role and 'to do' list.

What Makes Us Special:

You do! Our people bring the energy, the warmth, and the ideas that make the business extraordinary. As we grow, you’ll have the chance to grow too — with real opportunities to develop your skills and your career.

Diversity and Inclusion:

Our vision is to create a more rewarding world of travel and experiences. Delivering that requires diverse thinking and inclusive leadership. We are committed to building a workplace where people feel they belong and are valued for their perspective. Inclusion drives better decisions, stronger performance and more innovative outcomes. We actively encourage applications from people with different experiences and backgrounds, and are committed to ensuring our recruitment process is fair, inclusive and accessible.