Fullstack Engineer

Company

NestAI builds the adaptive operating system for modern battlefield operations. Most AI systems are built once, validated at deployment, and expected to stay sufficient after that. That assumption holds until conditions change, and in defence, they always do. Our team develops adaptive intelligence for unmanned and command systems: AI that continuously learns from operational data and adapts to changing conditions, deployed in environments where there is no internet, no GPS, and failure is not an option. NestOS, our open, modular, and interoperable platform, enables this at scale and keeps capability evolution under sovereign European control.

Founded in 2025 by Peter Sarlin, whose previous company Silo AI became Europe's largest AI acquisition, NestAI has grown to over 200 engineers and scientists and partners with leading European defence forces and industry. We're ambitious about what we're building and honest with each other. The bar is high, and so are the standards we hold ourselves to. But this is also a place built on humility, trust, and looking after each other. If that sounds like the kind of work you want to do, keep reading.

Role Description

NestAI builds the software and intelligence layer for autonomous defense systems, deployed in live operational environments where reliability isn't a nice-to-have — it's the whole point. As a Full Stack Engineer, you'll own the technical delivery and integration of that platform for our most critical partners.

This is not a traditional implementation or support role. It's a high-stakes, high-ownership full-stack engineering position: you'll build, adapt, and scale modern web applications, decision-support interfaces, and backend integration layers directly against complex customer environments — with the freedom to choose the right tool for the problem rather than inherit a decade of someone else's legacy decisions. We need a versatile engineer who can jump into unfamiliar codebases, connect disparate software ecosystems, and deliver intuitive, high-performance user experiences where software meets the mission.

Day-to-Day Responsibilities:

• Mission-specific full stack engineering: Take technical ownership of building, customizing, and deploying client-facing web applications, operational dashboards, and backend services.

• API & system integration: Design, develop, and deploy robust APIs and backend services that connect NestOS cloud and edge modules with external situational awareness and command systems.

• Frontend execution: Build responsive, high-performance decision-support UI designed for low-latency, mission-critical operational environments.

• Engineering craft under pressure: Hold a high bar for code quality, testing, and observability even while moving fast on-site.