Application Security Engineer

ABOUT US At OakNorth, we're on a mission to empower ambitious businesses and the communities they serve. Since 2015, we've lent over $21 billion across the UK and US, helped create more than 58,000 new homes and 36,000 new jobs, and supported hundreds of thousands of personal savers — all while driving economic growth in the markets we serve. ABOUT THE ROLE The Application Security Engineer is a hands-on, full-stack security role focused on fixing the hardest application and AI security problems — particularly those that cross team boundaries or involve architecture, authentication, and authorisation that automation cannot yet safely resolve.

You'll take remediation load away from engineering teams so they can stay focused on delivery, working closely with the teams that detect, prioritise, and track vulnerabilities. You'll also contribute to the development of OakNorth's internal coding agent platforms, so security fixes can scale safely. WHAT YOU'LL DO Fix complex application security vulnerabilities directly, including architectural weaknesses and issues in legacy technology that automated remediation cannot yet handle safely.

Lead remediation of problems that cross team and system boundaries, coordinating changes across multiple owners and services and seeing them through to resolution. Resolve authentication and authorisation weaknesses, including identity, access control, session and token handling, service-to-service trust and permission models. Act as a dedicated deli