Quantum Software Developer - Performance

About Xanadu

Xanadu’s mission is to build quantum computers that are useful and available to people everywhere.

At Xanadu, we are learners, innovators, researchers, collaborators and problem solvers. We are creating something that has never been built before. Few people in their life will be able to be a part of something like this, where if we are successful, the technologies we develop will solve some of the world’s most challenging problems, and literally change the world. And that is something to be excited about!

Your Role and Responsibilities

Building a high-performance software stack that makes optimal use of quantum hardware resources is key to realizing early, game-changing applications of quantum computing. As part of the PennyLane Performance Team, you will be responsible for the performance monitoring and benchmarking tooling for the PennyLane & Catalyst quantum software stack, as well as developing high-performance extensions including the PennyLane-Lightning simulator suite, ensuring PennyLane is the highest-performing framework for quantum computing.

You will:

• Develop the framework for benchmarking the compilation and execution pipeline, tracking quantum resources through the stack, and profiling the quantum software.
• Develop high-performance software components, adapting to new hardware platforms and programming paradigms.
• Convert abstract descriptions of algorithms into efficient & understandable software implementations.
• Interpret and communicate complex concepts to the wider team.
• Participate in software system specification, design, and quality assurance (e.g., requirements gathering, defining software architecture, documentation, verification & validation, etc.).
• Provide leadership in software best practices, including continuous-integration pipelines, unit testing, & code review.

Basic Qualifications and Experience:

• BSc in Computer Science, Engineering, Physics, Math, or a related field.
• Demonstrated education or training in quantum computing.
• Proficiency in high-performance Modern C++ (C++17/20 preferred) and Python.
• Deep understanding of computer architecture (CPU, GPU, memory hierarchy) coupled with hands-on experience in optimizing code for runtime and memory efficiency using professional profiling tools (e.g. perf, scalene, valgrind).
• Proven ability to rapidly diagnose and resolve complex issues across compiled and interpreted environments using industry-standard debuggers.

Preferred Knowledge and Experience:

• MSc, PhD in Computer Science, Engineering, Physics, Math, or a related field.
• Expertise in quantum computing, as demonstrated by extensive coursework, thesis, or peer-reviewed publications.
• Experience with writing complex quantum workflows and optimizing the use of quantum resources.
• Familiarity with code parallelization and accelerators: multithreading (e.g., OpenMP, C++ threads), multiprocessing (e.g., MPI), GPUs (e.g. CUDA, HIP/ROCm) or compiler offload directives.
• Experience in designing and implementing scalable & reproducible scientific workloads on HPC / supercomputer platforms or cloud hardware (e.g., AWS, Azure, GCP).