Software Engineer | Defence Start-Up | London

OHO Group (Lithuania); Greater London; On-site; GBP 65,000 - 100,000; Full time

Benefits offered by this job

Equity stake

Autonomy

Impactful work

Flexible hours

Job summary

OHO Group (Lithuania) is seeking a Software Engineer for our London-based defence start-up to design, implement, and deploy mission-critical systems with real-world impact. You’ll join a small, high-caliber team, enjoying significant ownership, technical depth, and responsibility for the systems you build.

The role suits a 4+ year software veteran who is a generalist across backend, infra and data, and who thrives in fast-paced environments.

Qualifications

• 4+ years of professional software development experience.
• Proficient in Python, TypeScript, Rust, Go, Java or C++.
• A true generalist comfortable across backend, infrastructure, data and automation.
• thrives in fast-paced, high-autonomy environments.
• Motivated by building technology with real-world impact, in defence/aerospace.

Responsibilities

• Own and contribute to end-to-end design, development and deployment of core systems.
• Collaborate across product, engineering and hardware teams to ship features.
• Build mission-critical software with a strong emphasis on reliability.
• Drive technical direction and take significant ownership of modules.

Skills

4+ years

Python

TypeScript

Rust

Go

Java

C++

Generalist

Fast-paced

Defence interest

Tools

Git

Job description

Software Engineer | Defence Start-Up | London

Software Engineer required for an early-stage defence technology start-up building mission-critical systems with real-world impact.

You’ll join a small, high-calibre engineering team designing, building, and deploying core technology. This is a deeply hands-on role for someone who wants significant ownership, technical depth, and end-to-end responsibility over the systems they build.

You are

• 4+ years of professional Software Development experience
• Proficient in Python, TypeScript, Rust, Go, Java, or C++
• A true generalist - comfortable working across backend, infrastructure, data, and automation
• Most effective in fast-paced, high-autonomy environments
• Motivated by building technology with real-world impact
• Interested in defence, aerospace, or national security technology

Nice to have

• Early-stage start-up experience
• Experience in robotics, embedded systems, ML, or real-time systems

Why Join?

• Competitive salary + meaningful equity
• Significant influence over product and technical direction
• Work on challenging engineering problems with genuine real-world impact
• Build mission-critical technology within the defence sector
• Join a small, world-class team with significant autonomy and trust

If you’re a strong Software Engineer who wants to build challenging technology that actually matters, let’s chat.

Software Engineer | Defence Start-Up | London