I

Infleqtion

Full-stack quantum hardware and software

Quantum Software Engineer - Compiler

Full-TimeUpdated on 10/23/2026
$145k - $170k/yr+ 401(k) match + Equity package
Entry, Junior, Mid, Senior
Bachelor's, PhD
Chicago, IL, USA
HybridHybrid; must be in the office three days per week. Travel up to 10%, potentially internationally.
Software EngineeringSystems Software Engineering

About the job

Requirements
  • A bachelor's degree in computer science, engineering, physics, or a directly related field is required.
  • High proficiency in programming is required, with fluency in Python preferred. Proficiency in alternative languages such as C/C++ or Julia is acceptable if the candidate can rapidly upskill in Python.
  • Experience with open-source quantum software frameworks such as Cirq or Qiskit is required; experience modifying these libraries is especially valuable.
  • Professional-level verbal, written, and presentation communication skills are required.
  • Ability to work in a highly collaborative, cross-functional, team-oriented, and matrixed environment is required.
  • Ability to thrive and produce results in a fluid, dynamic, and fast-paced environment is required.
  • Ability to learn new and complex topics quickly is required.
  • Resourceful problem-solving and the ability to collaboratively identify effective paths forward are required, along with demonstrated expertise in executing productization efforts.
  • Ability to be in the office any three days per week is required.
  • Ability to travel domestically and potentially internationally up to 10% is required.
Responsibilities
  • Conduct research and development toward advances in quantum technology, focusing on quantum compilation.
  • Deploy software optimizations to the Superstaq cloud platform using software engineering procedures including documentation, linting, testing, and type-checking.
  • Interface with Superstaq customers to understand their needs and support them in a timely fashion.
  • Contribute to the development of government and commercial proposals and execute global programs.
  • Collaborate with experimental physicists and software engineers to connect theoretical concepts with practical implementation.
  • Publish research findings in scientific journals and present them at conferences.
  • Stay current with developments in quantum computer architecture, quantum compilation, and related fields.
  • Provide guidance and support to team members and foster a collaborative research environment.
Desired Qualifications
  • A PhD in quantum computation, physics, computer science, or a directly related field is preferred.
  • Familiarity with quantum computing concepts such as error correction and fault tolerance, native gate decomposition, qubit mapping and routing, and variational quantum algorithms is preferred.
  • Experience with advanced open-source quantum software frameworks such as Stim is preferred.
  • Familiarity with professional software engineering best practices, including coverage, integration tests, type checking, unit tests, and version control, is preferred.
  • Experience with backend development using tools such as FastAPI for web frameworks and PostgreSQL or SQLAlchemy for databases is preferred.
  • Experience with cloud development, especially on GCP and AWS, is preferred.
  • Familiarity with CI/CD, automated actions, issue tracking, version control, and other GitHub features is preferred.
  • Familiarity with security best practices such as access control, encryption at rest, key rotation, and logging is preferred.
  • Exposure to or interest in front-end or GUI development, such as HTML/CSS, React, or PyQt, is preferred.

About the company

Infleqtion builds neutral-atom quantum hardware and complementary software for computing, sensing, and security. Its hardware uses lasers to cool and trap neutral atoms and perform quantum operations, with products like Sqale for computation, Tiqker clocks for precise timing, RF receivers for spectrum sensing, and inertial sensors for GPS-denied navigation; its Superstaq software optimizes algorithms across different quantum machines. The company differentiates itself by vertically integrating hardware and software and leveraging neutral-atom technology to scale, along with a history of strategic acquisitions and a NYSE listing. Its goal is to accelerate practical quantum adoption by expanding its roadmap and serving government and commercial customers across computation, sensing, navigation, and secure communications.

Company Size

201-500

Company Stage

IPO

Headquarters

Louisville, Colorado

Founded

2007

Get referred to Infleqtion

See people who can refer or advise you

Simplify Jobs

Simplify's Take

What believers are saying

  • NASA's August 27, 2026 award doubled QGGPf funding to $40 million.
  • September 10, 2026 Cisco collaboration opens distributed-quantum networking and telecom integration opportunities.
  • Shunkai became Japan's first operational neutral-atom quantum computer on September 7, 2026.

What critics are saying

  • Quantum hardware revenues remain contract-driven; NASA's $20 million extension ends after 2027.
  • Cisco and Riverlane can commoditize networking and error-correction layers, squeezing Infleqtion's software moat.
  • If 2030 fault-tolerant milestones slip, investors reprice INFQ as a science project, not a platform.

What makes Infleqtion unique

  • Infleqtion pairs neutral-atom hardware with Superstaq software, plus full-stack sensing and networking, since 2007.
  • On September 24, 2026, Sqale reached 30 entangled logical qubits using 80 physical qubits.
  • The February 2026 NYSE listing raised over $550 million, funding commercialization and deployment.

Help us improve and share your feedback! Did you find this helpful?

Benefits

  • Health Insurance
  • Dental Insurance
  • Vision Insurance
  • Life Insurance
  • Disability Insurance
  • Unlimited Paid Time Off
  • 401(k) Company Match
  • Paid Maternity/Paternity Leave
  • Student Loan Repayment
  • Family Leave
  • Short Term & Long Term Disability
  • Stock Options

Growth & Insights and Company News

6 month growth

1%

1 year growth

-1%

2 year growth

-9%
U.S. Securities and Exchange Commission
Oct 20th, 2026
EX-99.1

Defined terms included below have the same meaning as terms defined and included elsewhere in this Current Report on Form 8-K.

U.S. Securities and Exchange Commission
Oct 20th, 2026
8-K

Date of Report (Date of earliest event reported): February 13, 2026

The Defense Post
Oct 16th, 2026
Infleqtion secures UK funding for quantum signal-tracking system.

Infleqtion secures UK funding for quantum signal-tracking system. 2 minutes read UK-based Infleqtion has received 9 million pounds ($12 million) from the country's national innovation agency to develop a deployable quantum sensing system that can determine the direction of radio frequency (RF) signals, with potential applications in electronic warfare, spectrum monitoring, and navigation. The funding, awarded through UK Innovate's Quantum Missions Primer program, will support the second phase of the Quantum Direction Finding (QuDiFi) project. The project aims to move the technology from prototype testing toward a deployable product, with further work focused on performance, reliability, and evaluation in realistic operating environments. Infleqtion is developing a system called Quantum Spectrum-DF in collaboration with Italian defense company Leonardo. The companies have not disclosed a timeline for operational deployment. Using quantum sensors to locate radio signals. Direction-finding systems determine the direction from which a radio signal originates, helping operators locate transmitters and monitor activity across the electromagnetic spectrum. Military users can apply the technology to electronic intelligence and electronic warfare, while civilian applications include communications monitoring and infrastructure protection. Conventional systems often use multiple antennas to estimate a signal's direction. At lower frequencies, achieving the required performance can involve large antenna structures, creating size and integration challenges for mobile platforms. Infleqtion's approach uses Rydberg atoms, highly excited atoms that are sensitive to electric fields, to detect radio-frequency signals through optical measurements. By analyzing how these atoms respond to electromagnetic fields, quantum sensors can measure RF signals without relying on conventional antenna elements in the same way as traditional systems. The approach could reduce the size of direction-finding equipment and make it easier to integrate onto platforms with limited space. However, its practical advantages will depend on demonstrated performance under operational conditions, including the ability to identify and locate signals amid interference and competing transmissions. Defense and civilian applications. Leonardo is contributing to the effort, with potential applications across its defense electronics portfolio. Compact RF sensing could be relevant to aircraft, naval vessels, and other platforms where the size, weight, and power requirements of electronic systems are important considerations. The technology could also support passive sensing, which receives and analyzes existing transmissions rather than actively emitting a signal. Potential applications include spectrum surveillance and navigation, although these capabilities would require further development and validation. The project builds on broader UK efforts to advance quantum technologies for practical use. Quantum sensing is being investigated for applications including navigation, timing, and the detection of physical phenomena that conventional sensors may struggle to measure. For Infleqtion, the immediate objective is to establish whether Rydberg-atom sensing can deliver reliable direction finding in a compact, field-ready system. The funding will support that development, but the technology's eventual military and civilian roles will depend on the results of testing and subsequent integration work.

YFarmX
Oct 14th, 2026
Infleqtion wins £9 million for quantum radio direction-finding.

Infleqtion wins £9 million for quantum radio direction-finding. Innovate UK awarded Infleqtion £9 million to develop deployable Rydberg-atom radio direction-finding equipment with Leonardo, building on the QuDiFi prototype project. 00:0003:17 Infleqtion has won £9 million from Innovate UK to develop deployable quantum equipment for locating the direction of radio signals. The company announced the award on 13 October, with Leonardo collaborating on the project. The funding announcement covers the second phase of Quantum Direction Finding, or QuDiFi, within the Quantum Missions Primer programme. Infleqtion aims to build a Quantum Spectrum-DF product suited to realistic operating environments. The award takes a prototype towards field use. The next QuDiFi phase focuses on turning a tested prototype into robust equipment. Infleqtion describes work on performance, reliability, usability and validation in conditions representative of deployment. UKRI's November 2025 project announcement set out the earlier prototype programme under the lead name Coldquanta UK Limited. It covered sensor-head design, signal processing and integration with existing radio-frequency platforms, with a pathway towards smaller equipment and field trials. The new award continues that progression. A laboratory measurement can establish the sensing principle; a deployable product also has to keep working when its surroundings, platform and operator change. Highly excited atoms sense the radio field. Rydberg-atom sensors use atoms in highly excited states whose response to an electric field can be measured optically. Lasers probe the atomic response, providing information about an incoming radio signal. Radio direction-finding adds a spatial question: where is the signal coming from? A sensor can infer direction by comparing measurements taken at different positions or by analysing the field's pattern. A 2021 NIST demonstration measured the phase of a 19.18 GHz signal at two locations inside a caesium vapour cell. The phase difference allowed researchers to calculate its direction of arrival and compare it with a model. That earlier experiment illustrates the sensing principle behind this wider field of research. Compact sensors could fit on more platforms. Infleqtion aims to reduce the size of radio direction-finding equipment, particularly where conventional low-frequency systems require large antenna structures. Its proposed product uses optical measurements of atoms to support compact, broadband, passive sensing. That is relevant to platforms with limited space for antennas and associated electronics. The funded development will test whether the sensing approach can deliver useful performance in a practical package. The company's Quantum Spectrum product information describes its broader atomic radio-sensing approach. The new direction-finding project applies it to detecting and locating signals, with future applications including spectrum surveillance, passive radar and resilient navigation. Leonardo brings operational sensing requirements. Leonardo is collaborating with Infleqtion on the development programme. The award announcement includes Oliver Sims, Leonardo's electronic-warfare chief technologist, describing the potential to reduce the physical footprint of direction-finding systems. Innovate UK, part of UK Research and Innovation, is funding the work. The £9 million is an award for continued product development, with Infleqtion giving an approximate US-dollar equivalent of $12 million. The next test is whether the prototype's sensing capability can be retained in equipment that is reliable, usable and suited to its intended operating environment. That transition is the focus of the funded second phase.

Quantum Zeitgeist
Oct 13th, 2026
Infleqtion UK wins Innovate UK funding to build deployable Rydberg atom direction finder

Infleqtion UK is developing a quantum radio frequency direction finding system with funding from Innovate UK. The amount was not disclosed. The product, called Quantum Spectrum-DF, uses Rydberg atoms to detect and locate high-frequency signals with optical techniques instead of conventional antennas. Infleqtion says this allows a compact system for platforms that cannot carry traditional equipment because of weight or space limits. Leonardo is working with Infleqtion on the project. "For defence platforms, reducing size, weight and power consumption while preserving operational effectiveness is a significant advantage," said Oliver Sims, electronic warfare chief technologist at Leonardo. The system builds on an earlier tested prototype and targets defence and civilian uses, including spectrum surveillance, passive radar, and resilient navigation.