Senior Full Stack Engineer

Building a New Foundation for Cloud Security

The best security control doesn't detect a bad action. It removes the ability to perform it in the first place.

That's what Act does. We're an action-centric cloud security company focused on reducing cloud risk by removing excessive and unintended access across cloud environments. As AI is making attacks faster and less predictable, patching and detection can only go so far. So we make sure every identity in the cloud, human or machine, has only the access it actually needs, without turning security into an operational burden.

We're early-stage, well-funded, and built by repeat security operators who previously created Medigate (acquired by Claroty). We're building a team of exceptional people who take ownership from idea to outcome, with the autonomy to make decisions and drive their work forward. We care deeply about the customer, move fast, and enjoy building together.

If you want to build something that matters from the ground up and see your work go live within days, this is the place.

The role

We are looking for an experienced Senior 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

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.