Senior Java Engineer

About

Quantum Machines is a global leader in control systems for quantum computing, a field on the verge of exponential growth.
Our innovative hardware and software mark a groundbreaking approach in quantum computer control, scaling from individual qubits to expansive arrays of thousands.
At the core of QM lies a passionate and ambitious team committed to reshaping the construction and operation of quantum computers. Our work is fueled by a deep understanding of customer needs, driving us to deliver unparalleled solutions in this revolutionary field.

We are looking for a highly experienced Backend Developer – design and develop the core backend software layer over the company's specialized flagship product. It is a unique opportunity to join a team of top‑notch engineers and work on cutting‑edge technologies in a fast‑paced environment of quantum computation.

What Makes This Role Different

• Our backend team sits in the middle of everything – we're the orchestration layer between:
  • Hardware control systems (C++)
  • Client exposed SDK (Python)
  • Reporting and managing system (Go)
  • Our business logic (Java/Kotlin + Spring)

Requirements

• 5+ years building backend systems in any modern OOP language (Java, Kotlin, C#, Go, Rust, etc.).
• Deep understanding of OOP – you know when to use inheritance vs composition, and you can explain why.
• Concurrency expertise – race conditions, thread safety, and async patterns don't scare you.
• Experience building systems that scale – you've thought about throughput, distributed architectures, and made performance trade‑offs.
• Design patterns and architecture – you can discuss SOLID principles and explain architectural decisions, not just implement them.
• Code review, testing, and integration – you've been in the trenches and know what good looks like.
• You care about code quality – not perfection, but code that your future self (and teammates) won't curse at.

Strong Plus

• Java/Kotlin + Spring experience
• gRPC‑based communication
• Python programming
• Experience in polyglot environments

What This Means for You

• You'll own features end‑to‑end – from design conversations to production, across multiple systems and teams
• You'll collaborate constantly – with engineers working in different languages, explaining APIs, debugging integration issues together
• You need to think in systems – your code is one piece; you need to understand (and care about) how it all fits together
• When something breaks, you dig in – even if the bug is in Python code you didn't write, or a timing issue between services
• You make decisions – sometimes with incomplete information, and you take responsibility for the outcomes

You'll Thrive Here If You

• Ask questions when requirements are unclear rather than guessing
• Help teammates when they're stuck, and ask for help when you are
• Balance "perfect" with "good enough to ship"
• Communicate clearly in English (written and verbal)
• Think beyond your code and take ownership without being asked