Senior Software Engineer

About Us Act Security is an action-first cloud security platform built for the AI era.

For years, organizations have piled up access they never use. That debt was survivable when attacks moved at human speed. It isn't anymore. AI now finds and exploits access paths faster than any team can triage them, and AI agents are operating inside production systems with real autonomy to act. Access has become the attack surface, and chasing findings one at a time is a losing game.

Act systematically shrinks the access surface across your cloud, enforcing deterministic boundaries on what people, workloads, and AI agents can reach. We reason across identity, network, and AI access together — the three control planes that decide what anything can touch — and we enforce through the cloud-native controls you already own. No agents, nothing new to deploy, nothing taken offline. The result is a cloud that's structurally harder to attack and a security posture that holds between audits instead of quietly eroding.

We're early-stage, well-funded, and moving fast - built by repeat security operators who previously created Medigate (acquired by Claroty). If you want to build something that matters from the ground up and ship to production within days, this is the place.

Our Culture We live by three values: Win, Learn, Have Fun. We play to win- we set ambitious goals and hold ourselves to high standards. We learn constantly- from customers, from each other, and from our mistakes. And we have fun doing it: we believe great work happens when people enjoy working together.

What You'll Do

• Design and build backend systems that process complex cloud infrastructure data at scale
• Own features end-to-end: from architecture to implementation to production
• Work closely with Product and Research to turn security insights into real, usable capabilities
• 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

Requirements

• 5+ years of hands-on software development experience
• Strong backend skills (Node.js/TypeScript/Python/Gplang) alongside solid frontend experience (React)
• Experience working with cloud platforms (AWS, Azure, or GCP)
• Solid understanding of system design, data structures, and performance tradeoffs
• Strong sense of ownership, clear communication skills, and ability to move fast without cutting corners

Why Join Us

• Real ownership- this is an early-stage company where engineers drive decisions
• AI-native environment- you'll join an AI-native team. We help customers secure their AI workloads, build intelligent automation into our product, and use AI tools every day as part of how we build and ship.
• Top-tier team- founders with deep security and product experience, surrounded by a team of experts and backed by leading investors
• Competitive package- strong salary, meaningful equity, and the upside of joining early