Senior Software Engineer, Non-Realtime Controllers

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: Oxford, UK
Office commitment: Hybrid

Quantum is now, and it's built here. Oxford Ionics, now part of IonQ, is pioneering the next generation of quantum computing. Using our world-leading trapped-ion technology, we're building the most powerful, accurate and reliable quantum systems to tackle problems that today's supercomputers cannot solve.

We're looking for an enthusiastic and highly technical Senior Software Engineer for our non-realtime controllers team who will thrive in our dynamic cross-disciplinary environment. You will be working closely with our skilled software engineers, our systems teams who operate the physical quantum computers, and our world-leading quantum scientists to build and operate the software that controls the hardware surrounding our quantum computers.

Previous exposure to quantum systems is not required.

You will own areas of the hardware control surface end to end, from the device protocol up to a service running reliably across our fleet. This is a hands‑on engineering role and stays that way as you grow.

A working quantum computer is far more than the ion trap and its real‑time control electronics. It depends on a fleet of supporting hardware, including cryogenic compressors, vacuum pumps, power supplies, lasers, temperature controllers, wavemeters and cameras, that has to be kept observable, controllable and reliable. The timing‑critical operations such as gate waveforms and ion transport run on dedicated real‑time FPGA systems, while this team owns everything that does not need hard timing guarantees.

These services run on general‑purpose Linux hardware and must be rock‑solid, because a failed compressor or an un‑noticed pressure drift takes a whole machine offline.

This is a hands‑on engineering role, balancing delivery of your own areas with support for the teams and scientists who depend on them.

Key responsibilities include:

• Own a group of device controllers end to end, covering API design, implementation, rollout and ongoing operational health.
• Make services robust against the ways real instruments fail.
• Bring devices onto our current framework, and roll the result out across the fleet without disrupting running experiments.
• Improve the shared framework where a problem turns out to be common to many controllers rather than specific to one.
• Work closely with the systems teams and scientists who depend on these services, and strengthen observability, health checking and alerting.
• Raise the standard of the code around you through review, and bring less experienced engineers on by working alongside them.

To be…