Senior Application Security Engineer

Senior Application Security Engineer Security Platform - Remote UK £90,000 - £130,000 DOE + Equity The problem worth solving Most attacks don't start with someone breaking down the front door. They start with something that was already let in - a dependency, a package, a library that looked legitimate. The software your engineers are building right now is only as secure as everything it quietly pulls in from the outside world. That's a hard problem. AI is making it exponentially harder. Regulators are paying attention. Enterprise security teams are scrambling. The companies building the infrastructure to get ahead of this are the ones that matter right now. What the role involves Threat modelling and secure design reviews embedded with engineering teams from day oneSecurity code reviews and building the culture for engineers to do the sameOwning SAST, DAST and SCA tooling - writing automation, not just running productsHardening APIs, containers, IaC and CI/CD pipelines across a cloud-native stackPenetration testing and vulnerability assessments across services and infrastructureTechnical lead during incident response and red/blue exercisesBuilding security tooling from scratch - production quality, not proof of concept What they're looking for 5+ years AppSec - the depth of experience matters more than the path you took to get here Strong enough with code to hold your own in design reviews, architecture conversations and secure code reviews with senior engineers - you don't need to have been a software engineer but you need to think like one Strong AWS security experience - the entire platform runs on it Hands-on with security tooling - depth matters more than which products Low ego, collaborative, built for a small tight-knit team A hacker at heart - CTFs, bug bounty, home labs are all green flags The package Up to £130,000 depending on experienceEquity with real upside - technical founders who built the structure to reward engineers properly, IPO trajectory in 3-5 years35 days annual leave + birthday offFully remote, flexible hoursPension up to 8% matchedPrivate Medical dental and opticalPaid sick leave, income protection, life insurance Interested? Drop me a message. The details stay confidential until we've spoken. This isn't being advertised widely - if the problem resonates, it's worth a conversation.