Staff/Principal Frontend Software Engineer

Twenty; New York (NY); On-site; USD 192,000 - 455,000; Full time

Benefits offered by this job

Health plan

Parental leave

Paid holidays

401(k) with options

Job summary

Twenty Technologies seeks an accomplished Senior Frontend Engineer to own the frontend architecture for mission‑critical operator interfaces. You’ll lead UI direction, mentor engineers, and partner with backend, product, and design to ship real‑time, reliable web apps for cloud and on‑prem environments.

You’ll build scalable React/TypeScript applications, establish reusable patterns, and drive performance and testing practices in a high‑stakes setting.

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, RTL, Playwright or Cypress for E2E).
• Hands-on experience with state management libraries (Redux, Zustand, React Query).
• Strong collaboration with product and design to deliver excellent UX.
• Strong command of Git in a professional engineering environment, including CI workflows and code reviews.
• Bachelor’s degree in CS/Engineering or equivalent experience.

Responsibilities

• Architect and build React/TypeScript apps at scale.
• Design real-time UI experiences for complex data.
• Lead frontend architecture and design decisions.
• Build interactive visualization systems (graphs, timelines, streaming views).
• Create reusable frontend patterns and component libraries.
• Improve engineering reliability via reviews, standards, and testing."
• Mentor junior engineers through pairing and coaching.
• Coordinate cross-functional delivery of end-to-end features.
• Troubleshoot production issues and optimize frontend performance.

Skills

Frontend architecture

React/TypeScript

Performance optimization

Code review & testing

Mentoring engineers

Education

Bachelor’s degree in CS/Engineering

Tools

Git

Job description

About The Company

America is under sustained cyber attack. Our adversaries infiltrate our networks, steal our IP, and degrade the digital infrastructure that modern life runs on. They’ve learned—correctly—that those attacks rarely produce consequences.

About The Company

America is under sustained cyber attack. Our adversaries infiltrate our networks, steal our IP, and degrade the digital infrastructure that modern life runs on. They’ve learned—correctly—that those attacks rarely produce consequences.

Twenty was founded to change that, by making our adversaries think twice before they attack us. Our vision is American and allied primacy in cyberspace—a future where they cannot contest us, deterrence is assured, and the free world remains secure.

Founded in 2024, Twenty Technologies (www.twenty.io) industrializes offensive cyber operations for the U.S. and its allies. Headquartered in Arlington, Virginia, Twenty has raised $168M from Khosla Ventures, Accel, Caffeinated Capital, Friends & Family Capital, Point72 Ventures, General Catalyst, and In‑Q‑Tel.

Mission | On Site | Full Time | U.S. Citizenship Required / No Active Clearance Required

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.

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.

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.

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

• 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.

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

Eligibility & Diversity

Due to U.S. government contract and security requirements, this role is limited to U.S. citizens. Some positions may also require eligibility to obtain and maintain a U.S. Government security clearance. Any active 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, consistent with applicable law.

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

Compensation Range

Compensation Range: $192K - $455K