Reactor Software Engineer III

About Us

At Antares our long-term mission is to make clean energy abundant from Earth to the Asteroid Belt. Were fueled by the belief that advanced nuclear energy can strengthen our military solve the climate crisis elevate global living standards and expand humanitys presence in outer space. To achieve our mission were building mass-producible inherently safe deployable microreactors that can be used terrestrially underwater and in space.

Formed in 2023 the Antares team hails from SpaceX The White House MIT Rigetti Computing The Air Force General Atomics Relativity Space Ursa Major and National Laboratories like Los Alamos Idaho and Oak Ridge. Antares has raised over $130M in venture capital from top-tier investors and has over $13M in government funding.

About the Role

Antares is seeking a Reactor Software Engineer to build the software that operates tests and interfaces with our first-of-a-kind microreactor and its hardware-in-the-loop environments. This software sits between reactor controls instrumentation operator tools simulations and external data systems collecting live signals streaming telemetry executing commands and helping the system respond predictably to off-nominal conditions.

You will work across a codebase where the same controls and interfaces can run in simulation on a bench or hardware test stand and eventually against full-scale reactor this role you will help define data is acquired validated routed displayed and recorded. You will contribute to how commands are scheduled gated confirmed and executed; and how faults are detected surfaced contained and recovered from.

You will partner with controls electrical embedded systems safety and test teams to design implement and validate hardware-facing software for sensors data acquisition systems custom electronics operator displays simulations and HIL/HITL environments. Your work will be central to ensuring the reactor can be safely operated tested diagnosed and eventually deployed.

Key Responsibilities

• Develop reactor software for data acquisition telemetry processing command handling state management fault response operator interaction and automated test environments.

• Own features end-to-end from test specs and interface definitions through implementation code review integration and documentation.

• Build software that can drive both real instruments and in-memory simulations keeping controls and interfaces consistent across simulation bench HIL/HITL and reactor environments.

• Implement runtime control features such as timeline scheduling event/gate handling mode transitions command validation command feedback and telemetry streaming.

• Create and maintain clear software interfaces for hardware adapters telemetry sinks DAQs sensors controllers operator tools and external data systems.

• Implement data validation and quality logic so telemetry can be marked as valid invalid stale unavailable suspect or otherwise actionable by downstream software and operator tools.

• Develop fault-aware software behavior including detection classification containment recovery reset behavior diagnostics logging and observability.

• Write automated tests that validate real system behavior including hardware-facing workflows whenever practical.

• Support simulation HIL/HITL hardware bring-up integrated reactor testing and debugging across software/hardware boundaries.

• Collaborate with electrical embedded controls software test and systems teams to define interface control documents communication schemas data dictionaries and integration test plans.

• Participate in design reviews code reviews test readiness reviews and root-cause investigations during hardware integration and deployment campaigns.

Basic Qualifications

• Bachelors degree in Computer Science Computer Engineering Electrical Engineering Software Engineering or a related technical field.

• Experience developing clean maintainable production or project software for hardware-integrated distributed embedded robotics aerospace automotive industrial or mission-critical systems.

• Software Engineer I: 0-2 years experience

• Software Engineer II: 2-5 years experience.

• Strong Python 3 fundamentals including typed code dataclasses or equivalent structured data models exceptions testing and idiomatic code organization.

• Working knowledge of data structures object-oriented design fundamentals and software interfaces that are readable testable and maintainable.

• Familiarity with concurrent asynchronous or multi-process software patterns such as asyncio threads multiprocessing event loops IPC networking or message passing.

• Experience integrating software with sensors controllers DAQs instruments power supplies embedded systems simulations or other hardware-facing interfaces.

• Ability to design clear data models state machines command flows and testable system behaviors.

• Strong debugging skills across software hardware and system-integration boundaries.

• Experience with Git and collaborative engineering workflows including pull requests code review and technical documentation.

• Comfort working in an environment where requirements evolve through prototype testing hardware bring-up and cross-functional design tradeoffs.

• Strong written and verbal communication skills especially when working across software electrical controls test and systems engineering teams.

• U.S. person status or eligibility to obtain required export authorizations under applicable U.S. export control regulations.

Preferred Skills & Experience

• Experience with hardware or instrumentation software including DAQs sensors serial devices lab benches power supplies controllers or custom test stands.

• Experience with event-driven systems command and control software telemetry pipelines state-machine architectures autonomous mode management or fault-aware system behavior.

• Experience with messaging networking or serialization technologies such as MQTT NATS DDS ZeroMQ gRPC sockets publish/subscribe patterns or custom telemetry buses.

• Experience building simulation Hardware in the Loop fault-injection test automation or continuous integration environments for hardware-facing systems.

• Familiarity with Linux workflows containerized environments and modern Python tooling such as pytest type checkers linters uv or similar tools.

• Experience with C C Rust embedded systems interfaces binary data formats or C-style data structures.

• Experience developing mission-critical safety-critical or high-reliability software for aerospace robotics automotive industrial defense nuclear or medical systems.

• Ability to improve observability through logging metrics structured telemetry diagnostics and clear failure reporting.

• Experience contributing to formal design reviews interface control documents test plans hazard analyses or configuration-controlled releases.

• Curiosity about how software meets the physical world and a bias toward integration readability and testing over cleverness.

Pay Ranges

Software Engineer I: 120k-135k

Software Engineer II: 135k-160k

Your actual level and base salary will be determined on a case-by-case basis and may vary based on the following considerations: job-related knowledge and skills education and experience.

Culture

At Antares we like to specifically tie each role to our founding documents set of valueshere are the top five cultural values we think you should believe at your core to be successful:

• Think in Systems - Energy and Defense are complex ecosystems with numerous stakeholders with competing priorities conflicting policies perverse incentives and emergent and path-dependent properties. First principles thinking alone is insufficient. Think probabilistically and then take action. If you want to be certain then you are apt to be obsolete. Over-optimizing the components often degrades the system

• Obsess over the End User - The customer and end user are often not the same. We will never build globally competitive commercial products if we lose sight of our end users and their entire interaction with the product life cycle

• Be Unconstrained by Convention - Our only limits are the laws of physics. Many even experts will say what we are working on is impossible. They said the same about SpaceX reusing rockets. Generationally impactful companies by definition must accomplish the seemingly impossible. If it were easy it would have already been done. Never shy away from a solution because it has never been tried before and never choose to do something because thats how its always been done

• Go Where the Work Is - Never miss a chance to meet a customer user or stakeholder face to face even if that means hopping on a plane. If you cant make it find a teammate who can channel your intentions and go in your place. Deep work can be done from anywhere but we believe teams are built in person and aim to maximize our time together

• Operate in the Grey - Embrace nuance in pursuit of truth. Question every fundamental assumption

Equal Opportunity

Antares is an Equal Opportunity Employer. Employment decisions are based solely on merit competence and qualifications without regard to race color religion gender national origin/ethnicity veteran status disability status age sexual orientation gender identity marital status mental or physical disability or any other legally protected status.

ITAR Requirements

To conform to U.S. Government export regulations applicant must be a (i) U.S. citizen or national (ii) U.S. lawful permanent resident (aka green card holder) (iii) Refugee under 8 U.S.C. 1157 or (iv) Asylee under 8 U.S.C. 1158 or be eligible to obtain the required authorizations from the U.S. Department of State. Learn more about the ITAR here.

Required Experience:

IC