Frontend Software Engineer – Simulation Workbench in London

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 developing a platform used by Data Scientists and Simulation Engineers to build, train, and deploy Deep Physics Models. The core of this platform relies on handling massive volumes of complex simulation data, enabling high-fidelity multi-physics simulation through AI inference.

We are looking for a Senior Frontend Software Engineer to join our product team. You will be one of a small team of Front-end Engineers, collaborating in a cross-functional team with autonomy to drive implementation decisions. You will build and evolve the frontend that brings our platform to life — from rich 3D visualisations of simulation data to seamless API integrations powering complex ML workflows. You will design composable frontend architectures, optimise performance for data-heavy interfaces, and ensure our engineers and scientists can interact intuitively with massive datasets and simulation results.

As a senior engineer, you will also play a key role in shaping technical direction — authoring Technical Decision Records, mentoring less experienced engineers, and driving the standards that keep our platform reliable, secure, and performant. This is a role for a builder who loves crafting exceptional user experiences as much as they love designing robust frontend architectures.

What You Will Do

• Build and evolve a frontend platform that supports complex simulation and ML workflows — from 3D visualisations to seamless API integrations and data-heavy interfaces.
• Design and implement composable frontend architectures and component systems, including micro-frontend patterns, to enable scalable and maintainable development.
• Optimise user experience through advanced caching strategies, performance monitoring, layout and paint optimisation, and accessibility best practices.
• Design and implement advanced state management and data flow patterns to handle the demands of real-time simulation data and complex user interactions.
• Own your work end-to-end — from architectural design through to deployment and maintenance in a fast-paced, agile environment.
• Define performance standards and SLAs for the services you own; diagnose and resolve complex performance bottlenecks in rendering, layout, and data handling.
• Collaborate with backend engineers on the implementation of security risk mitigation strategies and performance optimisations for frontend applications.
• Drive best practices in CI/CD, automated testing, observability, and infrastructure-as-code; build and maintain deployment pipelines including zero-downtime and multi-service deployments.
• Author and review Technical Decision Records; participate in Technology Radar reviews to evaluate and adopt new tools and approaches.
• Mentor junior engineers, facilitate technical discussions, build consensus around decisions, and translate research needs into well-defined technical requirements.

What You Bring to the Table

• A passion for the craft — a drive for engineering excellence and a commitment to sponsoring that culture across the team.
• Strong software engineering foundations — algorithms, data structures, and system design, with a passion for writing clean, maintainable, and testable code. You are a frontend engineer, not a framework developer — you understand the web platform deeply (HTML, CSS, JavaScript, browser APIs) and can build excellent interfaces regardless of the tech stack.
• Architectural versatility — 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. Experience with React and TypeScript is expected, but your identity is not defined by them.
• Web platform depth — strong understanding of how browsers work: rendering pipelines, layout and paint, networking, caching, the JavaScript event loop, and Web APIs. You optimise from first principles, not from framework-specific recipes.
• API and data handling maturity — experience designing frontends that integrate with complex backends via REST, GraphQL, WebSockets, and SSE, with attention to caching strategies, data access patterns, and forward compatibility.
• Reliability and observability mindset — experience defining performance standards and SLAs, implementing monitoring/alerting, and optimising observability in production environments.
• Security and accessibility awareness — familiarity with OAuth/JWT, XSS/CSRF prevention, WCAG, and ARIA standards; experience collaborating with backend teams on security risk mitigation.
• CI/CD and deployment expertise — hands-on experience building and optimising CI/CD pipelines (e.g. NX, GitHub Actions, monorepos), including multi-service and zero-downtime deployment strategies.
• Data visualisation experience — building rich, interactive visualisations using libraries such as Plotly, ECharts, Three.js, VTK, or WebGL to expose complex simulation data to end-users.
• Diagnostic and optimisation skills — a proactive mindset with the ability to identify and resolve complex performance bottlenecks from first principles — in rendering, networking, and data processing — rather than relying on framework-level fixes.
• Communication and leadership — excellent communication skills to discuss data needs with research scientists and translate them into technical specifications. Experience mentoring engineers and facilitating technical decisions.

Ideally

• Polyglot Frontend Thinking: comfort working beyond the JavaScript ecosystem — whether that means WebAssembly, compiled-to-JS languages, or non-SPA architectures. Willingness to reach for the right tool rather than the familiar one.
• 3D and GPU Technologies: deep experience with WebGL, WebGPU, or WebAssembly for high-performance rendering of simulation data, meshes, and point clouds.
• Design Sensibility: understanding of the limitations and trade-offs of design, layout, and typography constraints in the browser, with the ability to work with designers to reach a middle ground.
• Advanced Testing Techniques: experience with fuzzing, deterministic simulation testing, or fault injection in production systems; strong foundation in E2E and integration testing across different architectural patterns.
• Domain Knowledge: understanding of 3D geometry processing (meshes, point clouds) and the specific data structures used in physics-based simulations.

What We Offer

• Equity options – share in our success and growth.
• 10% employer pension contribution – invest in your future.
• Free office lunches – great food to fuel your workdays.
• Flexible working – balance your work and life in a way that works for you.
• Hybrid setup – enjoy our new Shoreditch office while keeping remote flexibility.
• Enhanced parental leave – support for life’s biggest milestones.
• Private healthcare – comprehensive coverage.
• Personal development – access learning and training to help you grow.
• Work from anywhere – extend your remote setup to enjoy the sun or reconnect with loved ones.