Senior Full Stack JavaScript / TypeScript Engineer – Chrome Extension & SaaS

Posted yesterday

Only freelancers located in the U.S. may apply.U.S. located freelancers only

Summary

Job Description Summary We're looking for a senior full stack JavaScript / TypeScript engineer to join an active client engagement immediately. The work centers on taking a Chrome Extension from MVP to production, alongside a companion SaaS application used by the team managing the extension. General information This engagement is part of a larger product build for one of our clients. An MVP of the Chrome Extension has already been developed, and the focus now shifts to building, hardening, scaling, and shipping a production-ready release. The SaaS application serves the internal team that manages and operates the extension, and will be built in parallel. You'll be joining an existing engineering team with a project manager already in place. The role requires someone who can orient quickly in an active codebase, collaborate closely with teammates, and interface with project stakeholders when needed. Work is coordinated through Jira, and the team communicates via Slack and Zoom. You'll be onboarded with a Microsoft account that provides SSO access to the tools and systems you need from day one. Development work is performed by connecting to a secure dev workspace directly from your local IDE. Tasks and Deliverables - Take the Chrome Extension from MVP to a stable, production-ready release. - Contribute to the development of a companion SaaS application for the client's internal team. - Integrate into the existing engineering team and align with the project manager on priorities and delivery. - Engage with project stakeholders directly as needed throughout the engagement. - Maintain code quality, documentation, and engineering standards appropriate for a production product. Required experience - Senior-level full stack JavaScript and TypeScript experience. - Demonstrated experience building and shipping Chrome Extensions. - Strong front-end engineering skills, including a modern framework such as React. - Solid back-end experience with Node.js and REST API development. - Proven ability to onboard into an existing codebase and contribute without a long ramp-up period. - Experience working within a structured engagement — alongside a PM, an existing team, and external stakeholders. - Familiarity with Jira for task tracking and project coordination. - Excellent English communication skills; US-based or US timezone required. - Availability during standard US business hours, Monday through Friday. Nice to have: - Experience with SaaS architecture, including multi-tenant application patterns. - Familiarity with Chrome Extension APIs including content scripts, background service workers, and the Chrome storage API. - Background working in agency or client-services environments. Engagement highlights - Step into an active, well-scoped project with established project management and a clear path to production. - Work across two connected workstreams — a Chrome Extension and a SaaS platform — with room to take meaningful ownership. - Join an engaged team with strong client-side collaboration and defined stakeholder involvement. Additional information All candidates selected for engagement are subject to a standard background check prior to onboarding.

  • Less than 30 hrs/week
    Hourly
  • 1-3 months
    Duration
  • Expert
    Experience Level
  • $60.00

    -

    $75.00

    Hourly
  • Remote Job
  • Complex project
    Project Type
Skills and Expertise
Mandatory skills
JavaScript
React
CSS
Web Application
Activity on this job
  • Proposals:50+
  • Last viewed by client:yesterday
  • Interviewing:
    1
  • Invites sent:
    0
  • Unanswered invites:
    0
About the client
Member since Mar 31, 2026
  • United States
    Winter Park8:00 AM
  • $5.7K total spent
    6 hires, 6 active
  • 87 hours

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