Principal Software Engineer - Engineering Applications 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

The Principal Software Engineer role at PhysicsX is an individual contributor role with leadership and collaboration expectations. The Principal is expected to be an effective technical thought-partner to non-technical stakeholders and is expected to contribute strongly to an environment of growth and development in the craft of software engineering across the organisation. Engineering Applications make PhysicsX's AI platform usable by engineers in their daily work. The product group creates workflows and interfaces that span the engineering lifecycle, from design through manufacturing to operations, enabling engineers to harness AI capabilities. The suite ranges from ready-to-use applications that ship with the platform for engineers to use directly to a composable set of extensible components for teams who need to go further. Engineering Applications ensure that impactful AI capabilities are accessible to customers at scale.

What you will do

• Engage with product managers, designers, and users of Reference Applications to fully understand the what and why of the product’s functional requirements.
• Partner with the product leadership of Reference Applications to define the art of the possible with ambitious pragmatism, defining the how and when of product development.
• Take responsibility and accountability for the implementation of components and services by a team of software engineers, and actively participate in development by contributing to source-code, documentation, and CI/CD workflows.
• Design and maintain services that are fully interoperable with PhysicsX’s other platform services, while remaining independently versioned, tested, and deployed.
• Define, evolve, and advocate for a scalable, modular front-end architecture that enables reuse, rapid development, and long-term maintainability.
• Implement standardised instrumentation for metrics, logs, and traces and take responsibility for the teams’ prompt remediation of issues in production.
• Establish performance benchmarking to measure compliance with non-functional requirements, right-size infrastructure requests, and provide appropriate SLAs.
• Participate in establishing company-wide software engineering standards through engagement with the software engineering guild.
• Participate in the growth and development of software engineers.
• Participate in the recruitment and onboarding of software engineers.

What you bring to the table

• A passion for the evolving craft of software engineering and for sponsoring a culture of excellence in the craft.
• A proven ability to act as an effective technical thought-partner to non-technical stakeholders.
• A proven ability to lead teams of software engineers in a fast-paced and iterative environment, through active participation in problem solving, coaching, and architectural decision-making.
• A solid track-record of designing, building, and maintaining application services in distributed architectures.
• Background working with Kubernetes - CKA certification, is a nice to have.
• Experience with workflow orchestration, event-driven systems, and messaging (NATS, ArgoWorkflows).
• Proven track record building web-based user interfaces using a variety of architectural approaches - SPAs, server-rendered applications, hybrid architectures, micro-frontends - with a critical perspective on when each is the right choice.
• Deep understanding of frontend rendering strategies and their tradeoffs: CSR, SSR, streaming SSR.
• Micro-frontend architecture: module federation, runtime composition, independent deployment, and shared dependency management across teams.
• Monorepo platform experience: Turborepo/Nx/Workspaces, with ownership of shared tooling, build pipelines, and DX abstractions across multiple frontend packages.
• Advanced TypeScript: conditional types, mapped types, and template literal types, with the ability to design type-safe API layers (tRPC, Zod, OpenAPI codegen).
• Build toolchain depth: Vite internals, custom plugin authoring, bundle analysis, and measurable build performance optimisation.
• Large-dataset rendering: virtualisation strategies (TanStack Virtual), WebGL/Canvas/WebGPU for high-performance visualisation.
• Server state architecture: TanStack Query or equivalent, cache invalidation strategy, optimistic updates, background refetching, and avoiding over-fetching at scale.
• Proficiency in Python and Go, with experience in other languages a plus (Rust, C++).
• A strong understanding of the machine learning development lifecycle.

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.

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.