Senior Full Stack Engineer

BUILDING A NEW FOUNDATION FOR CLOUD SECURITY Act Security is building a new foundation for cloud security: ensuring applications have only the access they need, without adding operational overhead. As AI accelerates the discovery and exploitation of vulnerabilities, detection and patching alone can’t keep up. We believe security should go beyond detecting attacks to reduce what attackers can do in the first place. Founded by the team behind Medigate, which was acquired by Claroty, we’re a small team with ambitious goals. We stay close to our customers and trust the people closest to the work to make decisions and own the outcome. Some of our hardest problems are still ahead. If you want to tackle fundamental challenges with people who care deeply about their work and each other, we’d love to build with you. THE ROLE We are looking for an experienced Full Stack to join our team and own features end-to-end - from the UI down to the backend services and data that power our cloud security platform. WHAT YOU’LL DO - Design and build features end-to-end, from UI (React, TypeScript) to backend services and APIs - Build and maintain backend systems that process complex cloud infrastructure data - Design clean, efficient APIs that connect a fast, intuitive frontend to a scalable backend - Work closely with Product and Design to turn security insights into real, usable capabilities - Make pragmatic architecture decisions across the stack, balancing speed and long-term maintainability - Leverage AI tools as part of your daily workflow - we build with AI, not just for AI - Improve our codebase, tooling, and engineering practices as we grow WHAT YOU’LL BRING - At least 5 years of hands-on full stack development experience - Strong proficiency in React and TypeScript on the frontend, and Node.js (or similar) on the backend - Experience designing and consuming APIs, and working with relational or cloud-native databases - Experience with cloud platforms (AWS, Azure, or GCP) is a plus - Solid understanding of system design, data structures, and performance tradeoffs across the stack - Strong sense of UI/UX combined with solid backend engineering judgment - Strong sense of ownership, clear communication, and ability to move fast without cutting corners WORKING AT ACT - Learn from real problems. We learn from our customers, each other, and our mistakes, and use what we learn to improve what we build. - Build with AI. We use AI tools in our daily work, build intelligent automation into our product, and help customers secure their AI workloads. - Set a high bar, together. We pursue ambitious goals and hold ourselves to high standards. We also believe great work happens when people enjoy working together. - Share in what we build. We offer competitive compensation and meaningful equity, with the opportunity to help shape an early-stage company.