Forward Deployed Applications - Senior Software Engineer in London

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.

The Role

PhysicsX is building a new category of engineering software — one where physics AI models don't just augment existing workflows, but fundamentally redefine what's possible in design and operations. Our Product team is expanding a portfolio of Engineering Applications that bring this capability directly to the engineers, scientists, and operators who need it most. If you're excited by the challenge of turning cutting-edge AI and simulation research into tools that change how the world's most complex engineering problems get solved, this is the team to do it with.

You'll join the Forward Deployed Applications team, a group that sits at the intersection of product development and customer delivery. Your primary mission is to work closely with customers on real engineering problems — and to turn what you learn into generalised, reusable product capabilities that raise the ceiling for every PhysicsX user. This isn't a traditional customer-facing role or a pure product role: it's the feedback loop that keeps our product grounded in genuine engineering value.

What you will do

• Spend meaningful time in conversations — with users unpacking real engineering workflows, with Delivery teams translating those needs into concrete requirements, and with the Product team debating which patterns are worth generalising.
• Be a connector as much as a builder, and develop a strong instinct for which customer insights have product-wide implications.
• Bring both rigour and initiative: writing clean, well-considered code, contributing to architecture decisions, and pushing back constructively when a bespoke solution risks diverging from the product vision.
• Design a 3D visualisation that makes a fluid dynamics simulation instantly legible to a non-specialist, build a React interface that surfaces AI model outputs in a live operational context, or refactor a one-off delivery prototype into something the whole platform can build on.
• Serve as an effective development lead and mentor across multiple levels of engineering seniority, drive adoption of best practices, and facilitate complex technical discussions and decisions with clarity and decisiveness.
• Build consensus around technical decisions, present solutions effectively to leadership, actively contribute to Technical Decision Records and Technology Radar reviews, and commit fully to group decisions even when they differ from your own recommendations.
• Maintain broad technical knowledge while deepening your specialisation, adapt quickly to new teams, identify emerging technologies and trends, and exemplify accountability by balancing competing priorities and expressing them as well-defined trade-offs.
• Drive requirements definition for large features, allocate work to junior engineers, present detailed technical decision records with trade-off analyses, and contribute to your team's development, testing, and security standards through automation and compliance validation.
• Design multi-service systems that account for operational cost, performance, and reliability requirements, implement zero-downtime deployment strategies, define SLAs and quality-of-service metrics, and build proactive monitoring and alerting that scales effectively.

What you bring to the table

• Publish quality-of-service metrics and reliability guarantees, and effectively leverage caching and memoisation strategies to optimise service performance in collaboration with frontend engineers.
• Develop automated testing strategies to ensure compliance with established standards for API schemas, messaging, and data segregation and access control at the service level.
• Manage observability metric cardinality to optimise cost and performance, and develop schema drift mitigation strategies that minimise impact to dependent clients.
• Contribute to the design of composable frontend architectures, component systems, and advanced state management patterns, while driving adoption of type-safe practices through shared type libraries and developer coaching.
• Optimise layout calculation, paint, and JavaScript execution in the browser, design effective caching strategies, integrate real-time technologies such as WebSockets and SSE, and collaborate with backend engineers on end-to-end performance improvements.
• Work effectively with designers to navigate browser constraints around layout and typography, and collaborate with backend engineers on security risk mitigation and performance optimisation strategies.

Ideally

• Confidence working across the full stack — you're at home reasoning about frontend architecture in React and TypeScript as well as backend design in Python, and you understand the tradeoffs in both well enough to make and defend pragmatic decisions.
• Experience building on top of large, established codebases — you know how to move deliberately, contribute incrementally, and improve things without breaking them.
• A track record of delivering in customer-facing or time-pressured environments, with the judgement to know when to ship something fit for purpose now and when to push back in the interest of a more durable solution.
• The instinct to treat customer engagements as a source of product insight — you naturally ask why a workflow exists, not just how to support it, and you channel that curiosity into constructive, well-reasoned feedback to product teams.
• Familiarity with 2D and 3D data visualisation and the ability to make complex simulation or model outputs legible and useful to non-specialist users.
• An agile, collaborative working style — you engage seriously with code review, testing, and CI/CD, and you're as invested in the quality of your team's output as your own.

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.
• 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.
• Influence over hierarchy: We operate with a flat structure: good ideas win - wherever they come from.
• Sustainable pace, long-term ambition: Building meaningful technology is a marathon, not a sprint.
• Equity options - share meaningfully in the company you’re helping to build.
• 10% employer pension contribution - because investing in future matters.
• Free office lunches - to keep you energised and focused.
• 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.
• YellowNest nursery scheme - to help working parents manage childcare costs.
• 25 days of Annual Leave (+ Public Holidays) - because taking time to rest matters.
• Private medical insurance - 100% employee cover, giving you complete peace of mind.
• Wellhub Subscription - gain access to thousands of gyms, classes and wellness apps, supporting both physical and mental wellbeing.
• Eye tests - because good work depends on good health.
• Personal development - dedicated support for learning, development, and leveling up over time.
• Employee Assistance Programme (EAP) - confidential wellbeing support, available whenever you need it.
• Bike2Work scheme and Season ticket loan - to make getting to work easier and greener.
• Octopus EV salary sacrifice - for a simpler, more sustainable way to drive electric.

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.