Staff Frontend SWE

Twenty; United States; On-site; USD 150,000 - 210,000; Full time

Benefits offered by this job

Health benefits

Parental leave

Flexible PTO

401(k)

On-site parking

Job summary

Twenty seeks a Senior Frontend Architect to own the frontend architecture for mission-critical operator experiences. You will build high-performance interfaces that visualize real-time cyber operation data and lead technical direction for UI systems.

You will mentor engineers, collaborate with design, product, and backend teams, and ensure reliable delivery across cloud and on-premises environments. A strong focus on performance and secure engineering is essential.

Qualifications

• 8+ years of professional frontend software development experience.
• Deep expertise building production React.js applications with TypeScript.
• Strong command of modern web fundamentals (JavaScript/TypeScript, HTML, CSS).
• Led frontend technical initiatives and mentored engineers through delivery and growth.
• Experience building for performance at scale (profiling, optimization, rendering strategies).
• Experience with automated testing practices and frameworks (Vitest, React Testing Library, Playwright or Cypress for E2E).
• Hands-on experience with state management patterns and libraries (Redux, Zustand, or React Query).
• Strong collaboration with product and design to deliver excellent 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).

Responsibilities

• Architect and build sophisticated React/TypeScript applications that operate smoothly at scale.
• Design real-time UI experiences for complex cyber operation data, optimizing for speed and clarity.
• Lead frontend technical architecture and design decisions.
• Build and evolve interactive visualization systems (e.g., graphs, timelines, streaming views).
• Establish reusable frontend architecture patterns and component libraries for consistency and velocity.
• Raise engineering excellence via code review, standards, testing strategy, and performance practices.
• Mentor junior engineers through pairing, feedback, technical coaching, and knowledge transfer.
• Coordinate execution across design, product, backend, and operations to deliver end-to-end features.
• Troubleshoot production issues, lead frontend performance investigations, and improve reliability over time.

Skills

React.js

TypeScript

Frontend architecture

Mentoring

Performance optimization

Testing (Vitest)

Testing Library (RTL)

Playwright or Cypress

State management (Redux)

Git & CI

Education

Bachelor's degree in CS/Engineering

Tools

Vitest

React Testing Library

Playwright

Cypress

Redux

Zustand

React Query

Job description

About the Company

At Twenty, we’re taking on one of the most critical challenges of our time: defending democracies in the digital age. We develop revolutionary technologies that operate at the intersection of the cyber and electromagnetic domains, where the speed of operations exceeds human sensing and complexity transcends conventional boundaries. Our team doesn’t just solve problems – we deliver game-changing outcomes that directly impact national security. We’re pragmatic optimists who understand that while our mission of protecting America and its allies is challenging, success is possible.

Role Summary

You’ll own the frontend architecture for mission-critical operator experiences—building high-performance interfaces that visualize complex cyber operation data in real time. You’ll lead technical direction for UI systems, set the bar for engineering quality, and mentor engineers to move faster with confidence. You’ll partner closely with backend, product, design, and operational stakeholders to ship capabilities that must work reliably in both cloud and on-premises environments. You’ll be embedded in a cross-functional team building capabilities that go directly into operational use — small team, tight feedback loops, real consequences.

Who You Are

• You care about building software that has real-world impact in high-stakes environments.

• You lead with high standards and high support—clear feedback, strong mentorship, calm execution.

• You think in systems: performance, reliability, accessibility, and maintainability are first-class concerns.

• You make good tradeoffs under constraints and can explain them crisply to technical and non-technical partners.

• You enjoy turning complex data into intuitive workflows that help users make decisions quickly.

• You’re comfortable owning ambiguous problems end-to-end and driving them to measurable outcomes.

• You default to secure engineering practices and treat trust, safety, and correctness as non-negotiable.

What You’ll Do

• Architect and build sophisticated React/TypeScript applications that operate smoothly at scale.

• Design real-time UI experiences for complex cyber operation data, optimizing for speed and clarity.

• Lead frontend technical architecture and design decisions.

• Build and evolve interactive visualization systems (e.g., graphs, timelines, streaming views).

• Establish reusable frontend architecture patterns and component libraries for consistency and velocity.

• Raise engineering excellence via code review, standards, testing strategy, and performance practices.

• Mentor junior engineers through pairing, feedback, technical coaching, and knowledge transfer.

• Coordinate execution across design, product, backend, and operations to deliver end-to-end features.

• Troubleshoot production issues, lead frontend performance investigations, and improve reliability over time.

Qualifications

Must Have

• You have 8+ years of professional frontend software development experience.

• You have deep expertise building production React.js applications with TypeScript.

• You have strong command of modern web fundamentals (JavaScript/TypeScript, HTML, CSS).

• You have led frontend technical initiatives and mentored engineers through delivery and growth.

• You have experience building for performance at scale (profiling, optimization, rendering strategies).

• You have experience with automated testing practices and frameworks (e.g., Vitest, React Testing Library, Playwright or Cypress for E2E).

• You have hands-on experience with state management patterns and libraries (e.g., Redux, Zustand, or React Query).

• You have strong collaboration skills with product and design to deliver excellent UX.

• You have strong command of Git in a professional engineering environment, including branch workflows, code review practices, and CI integration.

• You have a Bachelor’s degree in CS/Engineering (or equivalent practical experience).

Nice to Have

• You have experience with complex data visualization (e.g., D3.js, Chart.js, or similar).

• You have worked with graph databases and understand graph query patterns (e.g., Neo4j).

• You have experience with real-time streaming data and production visualization of live systems.

• You have experience in defense, security, or other mission-critical domains.

• You have built UI experiences that surface AI/ML outputs in operational workflows.

• You have experience with component library or design system development (e.g., Storybook).

Benefits
What’s on the table:

• Health. Medical, dental, and vision plan options. Life / AD&D, disability coverage options.

• Family. Paid parental leave for eligible full-time employees. 12 weeks for birthing parents, 4 for non-birthing parents, 6 weeks for adoptive, foster, or intended parents through surrogacy.

• Vacation. Paid holidays and flexible PTO. Take what you need.

• Retirement. 401(k) with pre-tax and Roth options. HSA/FSA options, dependent care FSA.

• At the office. Commuter benefits. On-site garage parking. Bike storage. Building fitness center. Desk setup stipend.

Benefits vary by location, role, and eligibility. Full plan details provided during the interview and offer process.

Some positions may require eligibility to obtain a U.S. Government security clearance. Any clearance requirement will be listed in the role description.

Twenty is an equal opportunity employer. We consider all qualified applicants without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, veteran status, disability, or any other protected status.

If you need a reasonable accommodation during the hiring process, let us know and we will work with you.