Staff Software Engineer, Trading Platform - Charts

Summary  Are you a frontend engineer who treats rendering pipelines, frame budgets, and library API design as a craft? Topstep is looking for a Staff Software Engineer to help build a custom charting engine for the TopstepX trading platform — a framework-agnostic library that renders the real-time charts thousands of active traders rely on every day. The library is organized as overlapping rendering layers — candles, grid, indicators, positions, drawings — most rendered on Canvas 2D. Your work spans the layer system, real-time data plumbing, indicator math, drawing tools, and the public API the rest of the platform builds against. You'll also build and maintain the React binding that adapts the core for the TopstepX web app; a React Native binding will follow as the mobile app matures. A WebGL layer may be added later for higher-density visualizations. The core has no framework dependencies; the bindings are thin wrappers above it. This role is ideal for someone who has shipped a production charting or visualization library before, understands what it takes to keep an interactive UI smooth while data flows in the background, and has strong opinions on what makes a good API. You'll set the bar for performance, write the abstractions other engineers will consume, and help define what engineering excellence means for this initiative. Key Responsibilities Design and build core systems of the charting engine — rendering primitives (layer system, hit testing, dirty-region rendering, text measurement) and domain features (drawing tools, indicator math). Own the framework-agnostic core library architecture, including the public API that React, React Native, and direct consumers integrate against. Build and maintain the React binding — the thin wrapper layer that adapts the core's public API into framework-native components, hooks, and lifecycle integration. The React Native binding follows as the mobile app matures. Drive architectural decisions on canvas compositing, layer strategy, and main-thread vs. worker-thread boundaries. Define and uphold rendering performance standards across the engine — 60fps frame-budget discipline and pointer-interaction responsiveness under continuous data flow. Build the data integration layer that bridges the existing real-time data pipeline into the charting engine. Ensure charting engine is consistent and performant across a wide range of devices, from desktop to tablets to mobile.  Establish visual testing standards including pixel diffing, deterministic replay-based tests, and golden-image regression discipline. Lead architectural reviews and RFCs for the charting library, driving consensus on library architecture across the trading platform without direct authority. Mentor engineers on the charting team through code reviews, design reviews, pairing, and technical coaching. Balance technical debt with feature delivery based on long-term library health and consumer needs. Communicate technical direction, t...