Application Security Engineer

About the role: As our engineering and research organisation grows, so does the complexity of securing it. Our Application Security team is at the forefront of that challenge — building AI-native security tooling, embedding security into the development lifecycle at scale, and finding ways to make a small, highly capable team punch well above its weight. We're looking for an Engineering Manager to lead and grow the AppSec team. This is not a coordination role. You'll be leading a team of exceptionally senior and staff-level engineers who are deeply self-directed and technically excellent. To earn their trust and enable their best work, you'll need to be genuinely close to the craft — able to engage at depth on threat modelling, agentic security tooling, SDLC design, and application risk. You'll also own AppSec strategy and be accountable for how the function scales alongside a product organisation that is growing fast and leaning heavily into AI-assisted development. Important note: Infosec team management Tenets apply. Key Responsibilities: Lead, support, enable and grow the AppSec team — owning hiring, onboarding, performance, and career development for a team of Senior and Staff-level Security Engineers. Own the formalisation of AppSec strategy and roadmap, translating team input, business risk and engineering context into a clear, prioritised programme of work with measurable outcomes. Be a credible technical partner to your team — engage on threat models, security architecture, agentic tooling design, risk decisions, and get into the details when it matters. Define and maintain the team's operating rhythm: OKRs, quarterly planning, cross-team coordination, and leadership communication. Act as a key interface between AppSec and the rest of the organisation — building relationships with business leadership, engineering leads, the Developer Platform team, Architecture Working Group, and partner functions like Legal and Moderation, to embed security into how Synthesia builds. Participate in AI-assisted development security, including securing use of agentic coding tools and AI-generated code. Own AppSec's relationship with the broader Security function, aligning with other Infosec teams on shared risks and incidents. Represent AppSec externally with customers, auditors, and in SOC2/ISO42001 contexts. What's in it for you: Lead a small, senior team with high autonomy; work in a leading AI-company with high growth; build AI-native tooling end-to-end; operate at the intersection of product, platform, and security architecture. Requirements: strong communication across audiences; solid engineering background in application security; Python and JavaScript; AWS/GCP; GitHub Actions; meaningful people management; leadership in AppSec programs; AI-native security perspective; collaborative security mindset. Bonus: Kubernetes, Semgrep/Wiz/CrowdStrike/HackerOne/Claude Code/Cursor/StepSecurity; prior Staff/Principal experience. Benefits: flexible remote-friendly role in Europe or hubs; 25 days leave + holidays; referral scheme; home setup; up to 60 days remote per year; growth opportunities.