Full-Stack Engineer (App Team)

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.

The opportunity is to join IAG Loyalty and contribute to the development of the Avios App, a global loyalty platform used by millions of travellers worldwide. As a Full Stack Engineer, you’ll work within a cross‑functional product team to build and improve features across both React Native and .NET/C#. You’ll bring strength in one of these areas, alongside working experience in the other, and continue developing your capability across the full stack. We’re looking for engineers who are comfortable stepping outside their core specialism and are motivated to build a broader understanding of how mobile and backend systems come together to deliver great customer experiences.

What you’ll be doing:

• You’ll contribute to the development of features across the Avios App, working across both mobile and backend systems to deliver reliable, high‑quality functionality.
• While you’ll spend more time in your core area of strength, you’ll also gain hands‑on experience across the wider stack, building your confidence in working end‑to‑end.
• Working as part of a collaborative product team, you’ll partner with engineers, QA, Product Managers and Designers to deliver features that meet customer and business needs.
• You’ll be involved in the full development lifecycle—from implementation and testing through to deployment and ongoing improvements—developing a strong understanding of how production systems operate at scale.
• You’ll also take part in code reviews, technical discussions and team ceremonies, learning from more experienced engineers while contributing your own ideas.
• Over time, you’ll be supported to take on more ownership and continue growing your impact across both mobile and backend development.

What we need from you:

• Experience building applications in a commercial engineering environment.
• Strong experience in either React Native or .NET/C#.
• Working experience in the other — able to understand, navigate and contribute with support.
• Interest in developing full stack capability across mobile and backend.
• Understanding of APIs and modern development practices.
• Exposure to cloud platforms (AWS preferred).
• Strong communication and collaboration skills.
• A proactive mindset and willingness to learn and grow.

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.

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.

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.