Chief Software Engineer | Applied AI

Chief Software Engineer

YC Defence Tech Startup | London (Hybrid) | Up to £200k Base + Significant Equity

We’re partnered with an exceptionally well-backed YC defence tech startup founded by former engineers from Palantir Technologies, currently building one of the strongest engineering teams in Europe.

This YC-backed company is still early enough for genuine founding-level impact, but already operating with serious funding, elite technical talent, and massive ambition.

They’re looking for a Founding Lead Engineer to help define the technical direction of the business while building highly scalable, mission-critical systems from the ground up.

You’ll work directly alongside an elite founding team tackling complex problems across distributed systems, networking, infrastructure, and software/hardware integration in real-world operational environments.

The Role

As a Founding Lead Engineer within this YC startup, you will:

• Architect and build core systems from first principles
• Drive major technical and architectural decisions
• Lead development of scalable event-driven systems
• Work across backend infrastructure, networking, and hardware-adjacent systems
• Mentor and level-up engineers within a high-performance environment
• Help shape engineering culture, standards, and hiring as the company scales
• Stay deeply hands-on technically while influencing broader engineering strategy

Tech

The company primarily uses Rust internally, though they are intentionally language-agnostic when hiring.

Strong candidates could come from backgrounds including:

• TypeScript
• Java
• C++
• Go / Golang
• Python

This YC-backed team values exceptional engineering ability, systems thinking, and ownership mentality far more than specific language experience.

What They’re Looking For

• Outstanding software engineering fundamentals
• Experience building distributed or event-driven systems
• Strong understanding of networking, infrastructure, or systems engineering
• Previous technical leadership experience
• Ability to operate effectively in fast-moving startup environments
• Founder mentality and high ownership mindset

People management experience is useful but not essential — the focus is on technical leadership and execution.

Why Join?

• Rare opportunity to join a genuinely elite YC defence tech startup at an early stage
• Work alongside ex-Palantir engineers and world-class technical operators
• Founding-level influence over architecture, engineering culture, and company trajectory
• Extremely challenging technical problems with real-world impact
• Up to £200k base salary + meaningful equity package
• High-trust, low-bureaucracy environment built for exceptional engineers

Location

Hybrid working in London, with a strong preference for engineers who enjoy spending time in-office collaborating closely with the team.

If you’d be interested in hearing more about this YC-backed defence tech opportunity, feel free to reach out.