SECTION I · THE BRIEF
Brief #88501Updated 17 APR 2026REMOTELeverSOFTWARE COMPANIES
Employbl Dossier

Sr. Software Engineer, Frontend (UK)

Firstup is redefining the digital employee experience to put people first and lift companies up. We make communication solutions that build authentic engagement and create two-way conversation between employees and…

Location
Remote
Company size
170–500
Posted
2mo ago
Via
Lever
Section II — RestrictedMembers only
  • Comp band & equity package
  • Seniority & experience requirements
  • Interview process & rubric
  • Hiring manager & team context
  • Growth trajectory in this role
  • Offer & decision timeline

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Sr. Software Engineer, Frontend (UK) - Firstup

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Job Title
Sr. Software Engineer, Frontend (UK)
Job Location
Remote - UK
Job Description
Who We Are

At Firstup, our mission is to improve the employee experience at every moment that matters, large and small. As the communication pipeline for the world's workforce, we now serve 40 of the Fortune 100 companies, reaching and connecting more than 17 million employees daily.

Our employees are experts in the employee experience, workforce communications and technology.
Joining Firstup means joining a movement to make work better for every worker. As the world’s first intelligent communication platform, Firstup meaningfully engages employees at every moment from hire to retire, and delivers engagement insights to help companies support, promote and retain their talent. Our movement has taken root and is evident in our world-class customer base. Now we need your help. Ready to make a difference in the world?


Job Summary

The Sr. Software Engineer (FE) will lead the development of scalable, high-performance frontend architectures. You will drive engineering excellence through modern React patterns, robust testing strategies, and the strategic use of AI-assisted development tools to accelerate delivery without compromising quality.

Responsibilities
  • Core Engineering: Build scalable frontend applications using modern React patterns and a component-driven architecture.
  • Systems Design: Own the design and implementation of a reusable, accessible component library and documentation.
  • Testing & Quality: Define the frontend testing strategy (Unit, Integration, E2E) including visual regression and user interaction coverage.
  • Performance & Reliability: Optimize client-side performance and ensure production readiness through observability, error monitoring, and rapid incident resolution.
  • AI Integration: Leverage and advocate for AI-assisted tools (e.g., GitHub Copilot, Claude) to accelerate development while maintaining rigorous engineering judgment and accountability for code correctness.
  • Leadership: Drive team-wide best practices, conduct quality code reviews, and mentor engineers to elevate overall engineering quality.
  • Collaboration: Partner with Product and Design to translate requirements into intuitive UI, making informed technical trade-offs in the face of ambiguity.
  • Minimum Qualifications
  • Experience: 5+ years building reliable, high-performance frontend applications at scale.
  • Core Stack: Expertise in React (Hooks, State Management), TypeScript, and modern tooling (Vite, Webpack).
  • Testing: Proficiency with Jest, React Testing Library, and Cypress/Playwright.
  • UI/UX: Proven experience building design systems or component libraries with a focus on WCAG accessibility.
  • AI Literacy: Demonstrated ability to use and critically validate AI-assisted coding outputs (e.g., Claude, Copilot).
  • Education: Bachelor’s in CS or equivalent practical experience.
  • Preferred Qualifications:
  • Fullstack: Experience with Ruby on Rails, Node.js, or AWS/Cloud infrastructure (Docker, Kubernetes).

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    Firstup Headquarters Location

    San Francisco, CA

    View company profile

    Firstup Company Size

    Between 170 - 500 employees

    Firstup Founded Year

    2010

    Firstup Total Amount Raised

    $114,800,000

    Firstup Funding Rounds

    View funding details
    • Series E

      $10,000,000 USD

    • Series E

      $10,000,000 USD

    • Series E

      $36,500,000 USD

    • Series E

      $36,500,000 USD

    • Series D

      $25,000,000 USD

    • Series D

      $25,000,000 USD

    • Series C

      $22,000,000 USD

    • Series C

      $22,000,000 USD

    • Series B

      $13,300,000 USD

    • Series B

      $13,300,000 USD

    • Series A

      $8,000,000 USD

    • Series A

      $8,000,000 USD