ZeInvoice

Jobs

Build ZeInvoice with us

ZeInvoice is a free invoice, receipt, quote and estimate generator for freelancers and small businesses in the US and UK — no signup, no watermark, and documents generated right in the browser. We're looking for a full-stack developer to help build what comes next.

Full-Stack Developer (Next.js / TypeScript)

Contract
Freelance
Location
Remote (United States)
Compensation
Based on experience
Posted
October 1, 2026
Apply by email

The free tools are already live: four document generators, Word, Excel and PDF templates, and sourced guides.

What you'll work on

  • Generator features — per-line VAT and sales tax, new documents such as proforma invoices, purchase orders and packing slips.
  • Free calculators — a freelance rate calculator and a late-payment interest calculator.
  • Accounts and a Pro plan — sign-in, saved documents and clients, payment tracking, and a paid subscription.
  • Quality across the board — performance, accessibility and technical SEO on every page you touch.

Our stack

  • Today — Next.js 16 (App Router), React 19, TypeScript, Tailwind CSS v4, pdf-lib, docx and ExcelJS for documents, Resend for email, Markdown content, deployed on Vercel from GitHub.
  • Next — Supabase (Postgres and auth) and Stripe for subscriptions.

What we're looking for

  • 3+ years building and shipping production web apps with TypeScript and React.
  • Hands-on Next.js App Router experience: server components, route handlers, static generation, the metadata API.
  • You design clean APIs — validation, error handling, rate limiting, webhooks — and you're comfortable with SQL and Postgres schema design.
  • Experience with authentication (OAuth) and Stripe subscriptions, or the will to learn fast.
  • You care about Core Web Vitals, accessibility (WCAG AA) and technical SEO, not just whether it works.
  • You test what matters, end to end, with Playwright or similar.
  • You work autonomously and write clearly in English.

Nice to have

  • PDF, Word or Excel generation in the browser.
  • Transactional email and deliverability (SPF, DKIM, DMARC).
  • Multi-currency, VAT or sales-tax logic.
  • You've built tools for freelancers or small businesses before.

How we work

  • Freelance, fully remote — work from anywhere in the United States, on a schedule we agree together.
  • Async first — written specs, small pull requests, and every merge to the main branch goes live through Vercel.
  • No layers — you work directly with the founder.
  • Compensation — based on your experience and the scope of each mission, agreed before you start.

How to apply

Email contact@zeinvoice.com with the subject “Full-Stack Developer” and include:

  • a link to your GitHub or portfolio;
  • a few lines about something you shipped and are proud of;
  • your availability (days per week) and your rate.

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