We are looking for a full-time Front-End Developer to design and build the user-facing parts of our high-performance trading platform. You will help create clear, data-rich interfaces that allow traders and analysts to work efficiently and effectively.

You will collaborate closely with the Back-End Development Team and the Project Manager to deliver well-integrated systems. A key part of this role is your ability to openly discuss solution approaches, trade-offs, limitations, and pros/cons with the team—not just follow a specific pattern or library.

## Key Responsibilities
– Develop and maintain the front-end applications for our trading platform.
– Work with back-end developers and the project manager to ensure smooth integration across systems.
– Create multi-page layouts, menus, and workflows that balance usability with efficiency.
– Help shape the design and user experience of the trading platform, performance & risk manager, and backtesting engine.
– Build and optimize charting and data visualization features, using libraries such as TradingView or D3.js to support many chart types (including tables and multi-series chart packs).
– Continuously improve UI/UX for clarity, speed, and intuitive navigation.

## Qualifications
– Strong communication skills and the ability to collaborate effectively with developers, project managers, and business stakeholders.
– Strong design instincts—simplicity and efficiency—with the ability to turn complex needs into clean, user-friendly interfaces.
– Knowledge of financial systems or trading concepts is a plus.

## Core Stack (Required)
– React 18 + Next.js (App Router), TypeScript, TailwindCSS.
– Strong state management skills for high-frequency data (e.g., Zustand, Redux Toolkit, useSyncExternalStore).

## Real-Time Data & Performance
– Hands-on experience with WebSockets/SSE, including reconnection/backoff, authenticated socket connections, and topic re-subscription.
– Experience implementing backpressure, buffering, coalescing, and windowing to prevent UI thrashing under thousands of updates per minute.
– Data virtualization experience (e.g., react-virtualized, react-window) for large tables such as orders, positions, and trades.
– Familiarity with Web Workers/OffscreenCanvas and message passing to keep the main thread responsive.
– Understanding of latency budgets and frame-time profiling using React DevTools and browser performance tools.

## Charting & Visualization
– Practical experience with professional charting libraries (e.g., TradingView Charting Library, Lightweight Charts, Highcharts, D3).
– Real-time overlays such as best bid/ask, order book depth, last OHLCV, and order/position annotations.
– Multi-panel layouts (price, volume, indicators) with synchronized crosshairs and shared time scales.

## Architecture & Data Access
– Client-side caching and invalidation (e.g., TanStack Query/React Query).
– Schema-driven UI for instruments and venues.
– Use of Error Boundaries, Suspense, and progressive hydration/streaming for large Next.js pages.

## Auth, Security, and Roles
– Solid understanding of OIDC/JWT flows, token refresh/rotation, and WebSocket authentication.
– Role-based feature gating (read-only vs trading permissions).

## Testing, Quality, and Reliability
– Unit tests for critical transforms/parsers (e.g., Playwright/Vitest for end-to-end/interaction flows).
– Experience using feature flags, staged rollouts, and monitoring with Sentry/OpenTelemetry.

## Nice to Have
– Experience with desktop-like interfaces (drag-to-dock panels, resizable grids).
– Exposure to WASM for heavy computations (e.g., indicator calculations).
– Familiarity with FIX/crypto venue details such as tick sizes, lot sizes, and trading session behavior.

## Screening Questions
Please keep each answer to 4–8 sentences. Bullet points are allowed if they’re clear.

1) **UI migration (hrzk → Next.js):**
Choose ONE area from `hrzk.html` (e.g., Orders+Trades, Positions table, Equity/Drawdown). Explain how you would migrate it to React 18 + Next.js (App Router) + TypeScript + Tailwind. Include your folder structure and what you would build as client vs server components. We value your trade-offs, not a single “correct” method.

2) **Real-time data ingestion:**
Explain how you would handle WebSockets/SSE for high-frequency updates, including reconnect/backoff, authenticated sockets, and topic re-subscriptions. What failures do you expect in production?

3) **Backpressure + UI thrash prevention:**
Assume thousands of updates per minute for orders/positions/trades. Describe how you would implement buffering/coalescing/windowing so the UI stays responsive. Explain how you’d combine this with state management (e.g., Zustand/RTK/useSyncExternalStore) and virtualization (react-window/react-virtualized). What would you measure to demonstrate it works?

4) **Charting approach:**
We need fast, readable, data-rich charts (e.g., equity/drawdown, doughnut/bars). Pick a chart type from `hrzk.html` and explain which library you would use, your update frequency strategy, and the performance risks plus your mitigations.

5) **Auth + role gating:**
Explain how you would handle JWT/OIDC token refresh and WebSocket authentication, then implement role-based gating (read-only vs trading). Use an example such as “Cancel All Orders” or “Stop/Start Execution” and explain when you would hide, disable, or show a warning.

6) **Remote ownership + teamwork:**
Share one example where you took ownership remotely on an ambiguous task. Then describe how you would work with a small development team: how you ask clarifying questions, communicate risks early, and avoid shipping “local optimum” code that could break other parts of the system.

## What to Expect (Interview Process)
Our process is mostly asynchronous and focuses on real work. You’ll begin with a CV submission and a short structured application. Shortlisted candidates complete an asynchronous technical screen. Finalists complete a paid, time-boxed work sample aligned to the role. The full process typically takes 4–6 weeks.

## FAQs
– **Do I need to respond to the questions?** Yes. Please answer in an open format ideally via a cover letter. This is mandatory for screening.
– **Do I need live interviews?** Most steps are async to minimize scheduling friction; live calls are minimal.
– **Do I need to be on camera for the sample work?** No—screen + voice is enough.
– **What tools can I use to submit recordings?** Any common screen-recording or file-sharing tool is fine, as long as the video is easy to view.
– **Is the final task paid?** Yes. Final shortlisted candidates complete a paid, time-boxed work sample.