Senior Software Engineer - Developer Tools at Ionq

About IonQ: IonQ, Inc. [NYSE: IONQ] is the world’s leading quantum platform and merchant supplier - delivering integrated quantum solutions across computing, networking, sensing, and security. IonQ’s newest generation of quantum computers, the IonQ Tempo, is the latest in a line of cutting-edge systems that have been helping customers and partners including Amazon Web Services, and AstraZeneca achieve 20x performance results and accelerate innovation in drug discovery, materials science, financial modeling, logistics, cybersecurity, and defense. In 2025, the company achieved 99.99% two-qubit gate fidelity, setting a world record in quantum computing performance. Headquartered in College Park, Maryland, IonQ has operations in California, Colorado, Massachusetts, Tennessee, Washington, Italy, South Korea, Sweden, Switzerland, Canada, and the United Kingdom. Our quantum computing services are available through all major cloud providers, while we also meet the needs of networking and sensing customers across land, sea, air, and space. IonQ is making quantum platforms more accessible and impactful than ever before. Location: This role can be based at our office in Bothell, WA (US) or in Oxford, England (UK). Travel: Twice per year Job ID: 1452 The Role As a Senior Software Engineer for Developer Tools, you will be a key contributor to the software that connects quantum developers to IonQ's hardware. You will focus on contributing to quantum compiler tools and features that our users and internal research teams depend on to run applications. You will build tooling to give users deep insights into how their circuits are optimized and create intuitive, user-friendly interfaces for hardware-specific compiler passes, such as quantum error mitigation and quantum error correction, and ensure our tools are robust and well-documented. You will work closely with our Compiler, QEC, and Applications teams to take new features through development, testing, documentation, packaging, and release, and use software engineering best practices to document, distribute, and use them in quantum software applications. The Developer Tools team builds the critical software layer for the quantum ecosystem. In this role, you will help shape an ecosystem of tooling that turns high-level quantum circuits into optimized instructions for our quantum computers. Your work will directly impact the performance, reliability, and capabilities of quantum applications running on IonQ systems by focusing on the compiler's application-facing features and its connection to the hardware. The compiler is where quantum algorithms meet quantum hardware. Your work sits at the heart of this critical transformation. The tools you build will define how developers interact with our systems, enabling them to extract maximum performance, trust the compilation process, and tailor optimization strategies for their specific use cases. By focusing on compiler tools for applications, you empower developers to tackle real-world problems and push the boundaries of what's possible on quantum computers. You'll make advanced techniques accessible, from sophisticated error mitigation to hardware-aware compilation. This role offers a unique opportunity to work with world-class researchers and translate their innovations into production software that accelerates the path to quantum advantage for everyone. Responsibilities: • Design, build, and maintain compiler toolchains, optimization tools, and circuit transformation libraries for developer-facing applications. • Work with the Compiler and Applications teams to package, test, and document new compilation features for both internal and external developers. • Architect and implement interfaces for hardware-specific compilation features, giving developers deeper control and visibility. • Integrate automated error mitigation, quantum error correction, and other advanced compilation strategies into our cloud platform and SDKs. • Maintain comprehensive documentation, examples, and tutorials for compilation workflows. • Support the testing and validation of compilation features across different IonQ backends and system configurations, and capabilities such as mid-circuit measurement and branching. • Collaborate with the Applications Engineering team to understand and address customer needs related to compilation and circuit optimization. Requirements: • Bachelor's degree in Computer Science, Engineering, Physics, or a related field, or equivalent training, fellowship, or work experience. • 6+ years of professional software engineering experience in team environments. • Deep proficiency in Python, our primary language. • Experience with quantum computing, with an understanding of quantum gates and circuits. • Familiar with the fundamentals of quantum compilation, error mitigation and quantum error correction. • Experience with software maintenance, user community stewardship and software engineering best practices. • Experience working with research or academic concepts and integrating them into scientific software workflows. • Familiarity with Agentic AI coding tools and techniques such as skills, docstring generation, code review, and software engineering best practices. • A track record of creating clear, comprehensive technical documentation. • Experience with automated testing, CI/CD pipelines, and scientific software validation. • Strong collaboration skills, with experience working across research and engineering teams. Preferred Qualifications: • 8+ years of professional software experience. • An advanced degree (PhD or Master's) in Physics, Computer Science, or a related field with a focus on quantum computing. • A background in compiler development for either classical or quantum systems. • An interest in or experience with hardware-level and hardware-specific compilation, such as pulse-level control or dynamic circuits. • System-level programming experience with C++ or Rust for performance-critical code. • Deep experience with quantum compilers, circuit optimization, or quantum error correction. • Experience with quantum computing SDKs (Qiskit, Pennylane, Cirq). • Understanding of trapped-ion quantum computing systems and their specific noise characteristics. • Proficiency with or strong interest in open-source compiler tools like ucc and jeff • Publications or significant contributions to quantum computing research or open-source projects. The approximate base salary range for this position is $145,920 - $191,047 (USD). The total compensation package includes base, bonus, equity, and a range of benefit options found on our career site. Compensation will vary based on individual factors such as education, qualifications, and experience of the final candidate(s), specific office location, and calibration against relevant market data and internal team equity. Posted base salary figures are subject to change as new market data becomes available. Our benefits include comprehensive medical, dental, and vision plans, matching 401K, unlimited PTO and paid holidays, parental/adoption leave, legal insurance, and a home technology stipend. Details of participation in these benefit plans will be provided when a candidate receives an offer of employment. At IonQ, we believe in fair treatment, access, opportunity, and advancement for all while striving to identify and eliminate barriers. We empower employees to thrive by fostering a culture of autonomy, productivity, and respect. We are dedicated to creating an environment where individuals can feel welcomed, respected, supported, and valued. We are committed to equity and justice. We welcome different voices and viewpoints and do not discriminate on the basis of race, religion, ancestry, physical and/or mental disability, medical condition, genetic information, marital status, sex, gender, gender identity, gender expression, transgender status, age, sexual orientation, military or veteran status, or any other basis protected by law. We are proud to be an Equal Employment Opportunity employer. US Technical Jobs. The position you are applying for will require access to technology that is subject to U.S. export control and government contract restrictions. Employment with IonQ is contingent on either verifying “U.S. Person” (e.g., U.S. citizen, U.S. national, U.S. permanent resident, or lawfully admitted into the U.S. as a refugee or granted asylum) status for export controls and government contracts work, obtaining any necessary license, and/or confirming the availability of a license exception under U.S. export controls. Please note that in the absence of confirming you are a U.S. Person for export control and government contracts work purposes, IonQ may choose not to apply for a license or decline to use a license exception (if available) for you to access export-controlled technology that may require authorization, and similarly, you may not qualify for government contracts work that requires U.S. Persons, and IonQ may decline to proceed with your application on those bases alone. Accordingly, we will have some additional questions regarding your immigration status that will be used for export control and compliance purposes, and the answers will be reviewed by compliance personnel to ensure compliance with federal law. US Non-Technical Jobs. Due to applicable export control laws and regulations, candidates must be a U.S. citizen or national, U.S. permanent resident (i.e., current Green Card holder), or lawfully admitted into the U.S. as a refugee or granted asylum. Accordingly, we will have some additional questions regarding your immigration status that will be used for export control and compliance purposes, and the answers will be reviewed by compliance personnel to ensure compliance with federal law. If you are interested in being a part of our team and mission, we encourage you to apply!