Quantum Computing Software Engineer

About BlocQ BlocQ, Inc. is a deep-tech startup headquartered in Tokyo and Silicon Valley, on a mission to solve cybersecurity challenges in the quantum computing era. We research and develop algorithms and software for quantum computers, bringing together world-class quantum researchers, software engineers, and cybersecurity experts - many with roots at the University of Tokyo - to extract peak performance from quantum hardware. We are working toward the world's first commercialization of quantum digital computing. If you want to be at the frontier of that effort, we'd love to meet you. Role Overview We are looking for a Software Engineer to build the systems that run on quantum computers. You will join a team designing the world's first quantum digital computing applications, responsible for designing and implementing the system infrastructure and development platform needed to execute quantum algorithms efficiently on hardware. Your primary work will be developing compilers and transpilers that optimize and transform quantum circuits for specific hardware configurations - implementing efficient mapping and scheduling algorithms that account for hardware architecture and resource constraints. You will also build SDKs that make it easy for users to write and run quantum programs. A key mission of this role is turning theoretical methods conceived by researchers into scalable, maintainable software. You will work primarily in Python while selecting the best language and libraries for performance requirements, and you will actively contribute to code quality and development process improvements in a team Git workflow. Key Responsibilities Design and implement quantum algorithms for hardware deployment Develop transpilers and compilers for quantum circuits Design and develop middleware and SDKs to execute quantum algorithms and QEC protocols conceived by the research team efficiently and scalably Develop HPC backends leveraging multi-threaded and GPU parallel computation to accelerate large-scale quantum circuit simulation and decoding Build seamless integration interfaces with major open-source quantum software (e.g., Qiskit) and internal new-feature stacks (Senior) Select and design software architecture; lead product quality improvements and development process through CI/CD pipelines and test automation Required Qualifications Master's degree or higher in computer science, physics, mathematics, or a related field - or equivalent professional expertise 3+ years of programming experience with C++, Rust, or Python Experience in team-based software development using Git Deep understanding of object-oriented design, data structures, and algorithms; ability to write clean, maintainable code Preferred Qualifications Research or development experience in quantum computing technology Experience in compiler development, FPGA development, or low-level implementation of computing systems Experience in high-performance computing (HPC) and parallel-accelerated computing using OpenMP, CUDA, MPI, or similar Contributions to quantum computing OSS (Qiskit, Cirq, Stim, etc.) or experience designing and publishing complex libraries/APIs Experience building scalable compute platforms (API servers, batch processing) on cloud infrastructure such as AWS or GCP Compensation & Benefits Salary: Annual: ¥6M - ¥20M (annualized) Incentive: Stock options Raises: Determined based on performance Transportation: Fully covered Insurance: Health, pension, employment, workers' compensation Overtime pay: Paid per standard rates Work Conditions Employment type: Permanent (no fixed term) Probation: 3 months Working hours: 9:00-18:00 (60-min break) - ~10-45 hrs overtime/month Location: Shibuya, Tokyo (5-min walk from Shibuya Station) Remote: Remote-first (hybrid available) Days off: Saturdays, Sundays, national holidays, Golden Week, year-end/New Year Paid leave: 10+ days from the 7th month of employment Smoking: Non-smoking workplace Selection Process 2-3 interview rounds #J-18808-Ljbffr Blocq, Inc.