Senior Java Engineer

Description 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 Java Developer to design and develop the core backend software layer over the company's specialized flagship product. You'll build systems that handle bursty, high-throughput workloads — think thousands of requests per second with strict latency requirements. This means making real trade-offs around concurrency models, resource pooling, and distributed coordination. 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 Requirements: 5+ years building backend systems in Java/ Kotlin 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 Spring experience gRPC-based communication Python programming Experience in polyglot environments AI Coding agent experience 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