Software Engineer II— DES

About The Role The Simulation / DES squad builds the discrete-event simulator that validates warehouse designs before a single physical bot is deployed — bot movement, throughput, bottlenecks, deadlocks — all made visible through a rich, interactive front end. As a Frontend Engineer on this team you own the visual layer of the simulator: the replay player, congestion heatmaps, scenario builder and the metrics dashboard that help solutions engineers understand a warehouse at a glance. You will work directly with the simulation engine team to design the data contracts your UI consumes, and you will raise the bar for what a simulation front end can feel like in an industrial B2B product.

What You'll Do

• Build the replay & visualisation surface — Implement a frame-accurate replay player that renders bot trajectories, queue depths and flow states over time using Canvas 2D or WebGL.
• Own heatmaps and spatial analytics — Build congestion, throughput and deadlock heatmaps on top of a grid representation of the warehouse map; ensure they update in real time during live simulation runs.
• Build the scenario-configuration UI — Design and implement the parameterised scenario builder (stations, bots, highways, storage zones) that feeds the headless simulation engine.
• Design and consume simulation data contracts — Work with backend engineers to define efficient event-stream formats (WebSocket / SSE) and local state models that keep the UI responsive at high event rates.
• Build the metrics dashboard — Implement time-series charts (throughput, cycle time, bot utilisation, queue depth) with filtering, zoom and export.
• Maintain performance and correctness — Profile and optimise rendering at scale: 1,000+ simultaneous bots, dense event streams, smooth 60 fps playback.
• Write tests and own quality — Unit-test rendering logic, write visual-regression tests; own the definition-of-done for every feature you ship.
• Instrument your surfaces — Add product-analytics events (e.g. Mixpanel) for feature adoption and funnel analysis; add Grafana-linked error observability.

Minimum (required) Qualifications

• 4–8 years of professional frontend engineering experience.
• Proficiency in React (hooks, context, custom hooks) and TypeScript.
• Hands-on experience with Canvas 2D or WebGL for data-driven rendering.
• Experience building data-heavy or analytics-heavy UIs (charts, grids, maps).
• Familiarity with WebSocket or Server-Sent Events for real-time data.
• Solid understanding of browser performance: layout, paint, compositing, memory.
• Experience with state management (Zustand, Jotai, Redux, or similar).
• Comfortable working in a CI/CD environment (GitHub Actions, trunk-based development).

Preferred Qualifications

• Experience working on simulation, game, mapping or geospatial visualisation products.
• Familiarity with D3.js or similar data-visualisation libraries.
• Exposure to warehousing, logistics or robotics domain.
• Experience consuming and designing REST / gRPC APIs from the frontend.
• Contributed to a design system or shared component library.
• Exposure to feature-flag driven development (gradual rollouts, A/B experiments).
• Worked in a Spotify-style squad or cross-functional product team.

Technical Qualifications

• Core stack: React 18+, TypeScript, Vite / Webpack.
• Rendering: Canvas 2D API, WebGL (raw or via Three.js / PixiJS); understanding of GPU pipeline stages.
• Real-time data: WebSocket, SSE, client-side event buffering and replay.
• State: Zustand / Jotai preferred; context + reducers acceptable.
• Testing: Vitest / Jest for unit tests; Playwright or Cypress for E2E; Storybook for component isolation.
• Observability: instruments features with analytics events; reads Grafana dashboards for error rates.
• Tooling: GitHub, GitHub Actions CI, GCP-hosted APIs, Backstage for service discovery.
• Code quality: ESLint, Prettier, strict TypeScript; respects CODEOWNERS review process.
• Performance: uses Chrome DevTools / React Profiler to identify and fix rendering bottlenecks.

How We Work You work in the Simulation / DES squad, a small cross-functional team that owns the DES mission end-to-end. The squad is IC-led — a Staff Engineer sets technical direction; there is no engineering manager layer. You own your surfaces from design through production, including on-call for the frontend services you build. You are expected to work autonomously on feature-sized tasks, surface blockers early, and help define the definition-of-done for anything you ship.