Staff Frontend Engineer

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.

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 messy, 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 design decisions, from component architecture to state management patterns.

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

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

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 in production environments.

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

• 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 contributed to backend services to unblock full-stack delivery (e.g., Go).

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

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

Tech Environment (You Might Work With)

• React.js, TypeScript, modern web tooling (e.g., Vite/Webpack)

• Data visualization libraries (D3.js, Chart.js, and related ecosystems)

• Testing: Jest, React Testing Library, Cypress (and/or Playwright)

• CI/CD pipelines for secure, repeatable frontend deployments

• Graph databases (e.g., Neo4j) and graph-oriented data models

• Cloud and on-premises deployments (AWS and controlled environments)

Security / Work Environment

Some positions may require eligibility to obtain a U.S. Government security clearance. This role may involve work in a controlled environment.

If this role sounds like you, apply and share with us your interest.

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.