Senior Software Engineer, Back-end

About the team At Q-CTRL, Quantum Computing Engineering is a global team of software engineers and infrastructure experts, combining deep technical expertise with a startup mindset to deliver real impact through software innovation. Our work is underpinned by robust standards, and by embracing the three virtues. Our team excels in areas across back-end, front-end, machine learning, and platform engineering. We transform Q-CTRL’s world-leading technological breakthroughs into commercial software products with applications across defense, research, and industry. We work closely with Product, Design, and Research teams to accelerate the path to quantum advantage worldwide. About the role As a Software Engineer on the Boulder Opal team, you will work with brilliant engineers and researchers to design and build a scalable, high-performance backend system while directly contributing to our quantum controller infrastructure. A key part of your role will be maintaining and evolving the compiler stack that translates OpenQASM3 + OpenPulse programs for low-level quantum controllers, bridging the gap between high-level quantum programming and physical execution on QPUs. You will collaborate with cross-functional teams, product, infrastructure, frontend, and research, ensuring end-to-end delivery of cutting-edge solutions that power our SDKs and cloud-based offerings. This role is ideal for someone passionate about backend engineering and systems-level programming, with an interest in quantum computing and scientific software. What you'll be doing: Build the backbone of quantum tech: Design, develop, and optimize scalable backend services in Python. Own the compiler stack: Maintain and evolve the compiler that translates OpenQASM3 + OpenPulse programs into low-level controller instructions. Bridge research and engineering: Work closely with world-class researchers and quantum engineers, translating experimental needs into production-ready code and debugging real-world execution challenges. Experiment on quantum hardware: Get hands-on with QPUs, validating compiler output and controller behaviors through real device experiments. Engineer for performance: Deliver high-efficiency service-to-service communication using modern protocols (gRPC, GraphQL, REST). Raise the bar on quality: Shape and enforce best practices for clean, secure, and reliable code while contributing to robust testing and documentation. Shape the future stack: Help define the software practices, tools, and design patterns that will power the next generation of quantum control systems. Deliver end-to-end solutions: Collaborate with product, frontend, and infrastructure teams to ship integrated solutions used across Q-CTRL’s products. Other duties within the Employee's skills and experience, or with reasonable training. Ideally you'll have: Bachelor’s degree in Computer Science, Engineering, or related field. 5+ years of backend software development experience with Python. Proven experience writing maintainable, testable code in a professional setting. Proven ability to mentor junior team members and accelerate their contributions. Strong collaboration and communication skills across cross-functional teams. Experience with quantum hardware control systems (or similar) or pulse-level programming (e.g., OpenQASM3, Qiskit Pulse, Qua). Familiarity with popular Python web frameworks (Django, Flask, FastAPI). A track record of leading or mentoring in technical projects, particularly in early-stage or research and development-heavy environments. It would be fantastic (but not essential) if you bring: Familiarity with formal language design (e.g. LL(*) or PEG parsers) and compiler theory or ecosystems (e.g. LLVM/MLIR). Experience with implementing CPython extension modules with systems programming languages such as C++ or Rust for accelerating Python programs. Knowledge or exposure to adjacent technologies such as FPGA programming, low-latency or real-time systems. About Q-CTRL Q-CTRL is the global leader in AI-powered quantum control infrastructure software. We build the tools that make quantum technology useful, solving the hardest challenges in quantum computing and quantum sensing to deliver real-world impact. Founded in 2017, we operate globally with offices in Sydney, Los Angeles, San Francisco, Berlin, and Oxford. Our teams bring together technical and multi-disciplinary expertise across the product lifecycle, and we’re hiring talent to help scale every part of the business. We work quickly to turn cutting-edge science into deployable technology. In 2024 we raised US$113 million in Series B funding, the largest aggregate investment for a quantum software company. Six months later we delivered the first commercial quantum advantage with Ironstone Opal, our field-validated quantum navigation solution for defense and industry. At Q-CTRL, we prioritize outcomes over hours. We offer flexibility, equity potential, and competitive benefits that reflect our high-performance culture. If you’re ready to help shape the future of quantum, we’d love to hear from you #J-18808-Ljbffr