Software Developer Aerospace Defense Jobs (NOW HIRING)

About us
PhysicsX is a deep-tech company with roots in numerical physics and Formula One, dedicated to accelerating hardware innovation at the speed of software.
We are building an AI-driven simulation software stack for engineering and manufacturing across advanced industries. By enabling high-fidelity, multi-physics simulation through AI inference across the entire engineering lifecycle, PhysicsX unlocks new levels of optimization and automation in design, manufacturing, and operations - empowering engineers to push the boundaries of possibility. Our customers include leading innovators in Aerospace & Defense, Materials, Energy, Semiconductors, and Automotive.
Who We're Looking For
You have spent your career inside aerospace and defense - in engineering programs, advanced development, or technical consulting and can hold a substantive conversation with a chief engineer or a VP. You are energized by the challenge of turning a customer relationship into a growing program - identifying what's next, building the coalition to get there, and then delivering it.
You understand how aircraft development, defense acquisition, and advanced manufacturing work: how decisions get made, where the hard problems live, and what matters to both leaders and working-level engineers.
You have enough ML and data science depth to lead conversations with potential customers, work with technical experts to scope work, and lead cross-functional delivery teams. You know the simulation domain well, ideally with hands-on experience. You communicate clearly and you read people well. You are highly self-directed: you determine your own priorities and own the follow-through.
You may already have a visible presence in the A&D community - at technical conferences, in professional networks, or through published work. If not, you're building it.
You have 8+years of experience in A&D in commercial, product, program, or engineering roles.
Note: This position may require access to information protected under U.S. export control laws and regulations, including the Export Administration Regulations (EAR) and the International Traffic in Arms Regulations (ITAR). Please note that any offer for employment may be conditioned on authorization to receive software or technology controlled under these U.S. export control laws and regulations without sponsorship for an export license.
This Role
This is a high-profile leadership role in our US Delivery organization - with one foot in business development and one in execution. You will lead business development conversations with engineering and manufacturing leaders at A&D players - and close them. You'd own the commercial outcomes, the customer relationships, and the delivery results that follow. Internally, this role is called a Delivery Engineer.
In practice, this means:

• Driving new business development across A&D - proactively identifying and qualifying opportunities through your network, industry events, and via direct engagement with prospective customers
• Helping to shape our A&D go-to-market strategy - events, content, customer references, and relevant capabilities
• Leading initial proposal and discovery conversations with senior engineering/ manufacturing/ program leaders
• Leading proposal development and scoping in partnership with commercial stakeholders
• Leading delivery projects at enterprise customers: establishing and executing technical plans, overseeing teams, and keeping focus on customer outcomes and adoption
• Owning strategic relationships with senior customer stakeholders, creating and executing account plans, and driving customer retention and footprint expansion
• Synthesizing customer needs into actionable product feedback; working with the Product team to shape how the PX Platform evolves based on what you see in the field
• Maintaining a visible presence at major A&D industry events, building PhysicsX's reputation in the domain
• Traveling to customer sites and industry events, on average 1-2 weeks per month.

This role is based in New York; hybrid arrangements are possible.
What We Offer
Build what actually matters
Help shape an AI-native engineering company at a formative stage, tackling problems that genuinely matter for industry and society. This is work with real-world impact - and something you can be proud to stand behind.
Learn alongside exceptional people
Work with a high-caliber, collaborative team of engineers, scientists, and operators who care deeply about doing great work, and about helping each other get better. We come from diverse backgrounds, but we share a commitment to operating at the highest level and addressing some of the most complex challenges out there. If you're ambitious, thoughtful, and driven by impact, you'll feel at home.
Influence over hierarchy
We operate with a flat structure: good ideas win - wherever they come from. Questioning assumptions and challenging the status quo isn't just welcomed, it's expected.
Sustainable pace, long-term ambition
Building meaningful technology is a marathon, not a sprint. We believe in balancing focused, ambitious work with a life beyond it. Our hybrid model blends time together in our New York office with work-from-home days, giving you the flexibility to work sustainably while staying connected in person.
And it doesn't stop there ...
Equity options - share meaningfully in the company you're helping to build.
5% contribution to 401(k) - build long-term security with a strong retirement plan.
Free team lunch 1x/week - good food, great company, and space to connect.
Private health insurance - comprehensive cover for you, offering total peace of mind.
Enhanced parental leave - 3 months full pay paternity and 6 months full pay maternity leave, to provide extra flexibility during the moments that matter most.
20 days of Annual Leave (+ Public Holidays) - because taking time to rest matters.
Personal development - dedicated support for learning, development, and leveling up over time.
Gympass / Wellhub (subsidized) - for you and up to 3 family members, supporting both physical and mental wellbeing.
Flexible Spending Account (FSA) - set aside pre-tax dollars for eligible healthcare expenses.
Watch this space, we're continuing to build this as we grow...
Salary range: $175,000 - $250,000 depending on experience. Seniority will be assessed throughout our interview process.
We value diversity and are committed to equal employment opportunity regardless of sex, race, religion, ethnicity, nationality, disability, age, sexual orientation or gender identity. We strongly encourage individuals from groups traditionally underrepresented in tech to apply. To help make a change, we sponsor bright women from disadvantaged backgrounds through their university degrees in science and mathematics.
We collect diversity and inclusion data solely for the purpose of monitoring the effectiveness of our equal opportunities policies and ensuring compliance with UK employment and equality legislation. This information is confidential, used only in aggregate form, and will not influence the outcome of your application.