Senior Application Security Engineer in City of Westminster

As IAG Loyalty evolves into a Platform as a Service business, we are looking for a talented and passionate Senior Application Security Engineer to join our security engineering team. You will have a background in software engineering and a deep interest in application and API security. You thrive on collaboration, enjoy helping others grow, and see security as an enabler - not a blocker. You will be an AppSec advocate who supports our engineers in identifying and addressing security issues across the software development lifecycle. You will be part of a small, dynamic team within the Product department that drives IAG Loyalty's digital transformation, technology strategy, and product direction. Our cloud-native platform powers the Avios currency and the digital experiences used by millions of loyalty members. This is a great opportunity to work with cutting edge technology in a fast paced, agile environment. This role is based out of our London office. We call our approach to hybrid working The Blend - it is 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 you will be doing:

• As a Senior Application Security Engineer, you will lead the application security practice within the IAG Loyalty security team, taking responsibility for key security KPIs in this area.
• You will champion secure software development by working closely with engineers and product teams, embedding security practices into our engineering culture.
• You will provide training, offer expert advice, and drive awareness of security from the earliest stages of design through to deployment.
• You will help integrate automated security tooling and checks into our CI/CD pipelines, facilitate threat modelling sessions, and review security sensitive design decisions around authentication, cryptography, and logging.
• You will also ensure that tools such as SAST, DAST, and SCA are effective and efficient, and that testing programmes — including pen testing, vulnerability scanning, and bug bounty — are delivering value.
• You will triage vulnerabilities, support engineering teams with practical mitigations, and contribute to documentation that strengthens our internal standards and processes.
• Maintaining a strong security culture will be a key focus, and you will also support internal and external audits where needed.

Experience required:

• Experience in software engineering, with a strong security mindset.
• Deep understanding of web and API vulnerabilities, including the OWASP Top 10.
• Proficient in coding, scripting (e.g. Python, Bash), and automating security in CI/CD.
• Hands on experience with security tools like SAST, DAST, and SCA.
• Familiar with cloud environments (especially AWS), containers, and microservices.
• Comfortable reviewing technical designs, performing threat modelling, and advising on secure architecture.
• Strong communicator who collaborates well with engineers and promotes secure by default practices.

We might not be right for you if:

• You only want to focus on your to-do list; we are 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 are 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 would love to chat and see if you could be a great fit.

Equity, Diversity and Inclusion at IAG Loyalty:

Our vision, 'to create the world’s most rewarding experiences,' applies not only to our customers but for our colleagues too. It is about taking belonging seriously, actively fostering a culture where everyone feels welcomed and valued by embracing diverse identities, personal histories, and perspectives. This commitment makes IAG Loyalty a rewarding place to work and enhances our ability to solve complex problems, drive innovation, and better serve our customers and communities. Please let us know if we can make any reasonable adjustments to support your interview process with us.