# Senior Frontend SWE
**Company:** [Twenty](https://hotfix.jobs/companies/twenty)
**Location:** Washington, DC
**Experience:** 5+ years
**Skills:** React, TypeScript, JavaScript, HTML, CSS, Vitest, React Testing Library, Playwright, Cypress, Redux, Zustand, React Query, Vite, webpack, Git
**Posted:** 2026-04-08
> Builds high-performance React/TypeScript interfaces for real-time cyber operation data visualization. Owns frontend features end-to-end, focusing on performance, testing, and collaboration in mission-critical environments. Requires 5-8 years experience.
## Job Description
## What You'll Do

- Build sophisticated React/TypeScript features and components that operate reliably at scale.
- Implement real-time UI experiences for complex cyber operation data, optimizing for speed and clarity.
- Contribute to frontend architecture and design decisions alongside your teammates.
- Build and maintain interactive visualization components (e.g., graphs, timelines, streaming views).
- Write and maintain automated tests across unit, integration, and end-to-end layers.
- Participate actively in code review — giving and receiving feedback that raises the quality bar.
- Identify and address performance issues, technical debt, and reliability gaps proactively.
- Collaborate with design, product, backend, and operations to deliver well-integrated features.
- Support engineers through pairing and practical feedback on their work.

## Qualifications

### Must Have
- 5–8 years of professional frontend software development experience.
- Strong, production-tested expertise in **React.js** and **TypeScript**.
- Solid command of modern web fundamentals (**JavaScript/TypeScript**, **HTML**, **CSS**).
- Experience building and shipping features for performance at scale (profiling, optimization, rendering strategies).
- Hands-on experience with automated testing frameworks (e.g., **Vitest**, **React Testing Library**, **Playwright** or **Cypress**).
- Experience with state management patterns and libraries (e.g., **Redux**, **Zustand**, or **React Query**).
- Experience with modern build tooling (e.g., **Vite** or **Webpack**) and CI/CD pipelines.
- Collaborate effectively with product and design to deliver high-quality UX.
- Strong command of **Git** in a professional engineering environment, including branch workflows, code review practices, and CI integration.
- Bachelor's degree in CS/Engineering (or equivalent practical experience).

### Nice to Have
- Experience with complex data visualization (e.g., **D3.js**, **Chart.js**, or similar).
- Exposure to graph databases or graph query patterns (e.g., **Neo4j**).
- Experience with real-time streaming data and live system visualization.
- Worked in defense, security, or other mission-critical domains.
- Built UI experiences that surface AI/ML outputs in operational workflows.
- Experience contributing to component libraries or design systems (e.g., **Storybook**).">
**Apply:** https://hotfix.jobs/jobs/senior-frontend-swe-at-twenty-84a9ff1f-2548-4a34-9961-678c3b2fe8a9
**Canonical:** https://hotfix.jobs/jobs/senior-frontend-swe-at-twenty-84a9ff1f-2548-4a34-9961-678c3b2fe8a9