How I'd build ContractorAI
I'd ship a Next.js frontend with a Postgres backend, Stripe for billing, Twilio for SMS notifications, and Redis for async jobs. The MVP would take roughly 200-240 hours to ship - that's 5-6 weeks at 40 hours per week, or 8 weeks at part-time velocity. I'm being conservative here because contractor software is deceptively complex; you're not just building forms, you're building reliability around money and commitments.
Day-by-day plan
Week 1: Provision Postgres schema for contractors, properties, estimates, change orders, and subcontractors. Set up Next.js with auth via Magic Links (Resend), not OAuth - contractors default to email. Deploy to Vercel with environment parity.
Week 1-2: Wire Stripe billing: three-tier pricing, seat scaling, and churn prevention. Build the payment recovery flow for failed cards - contractors forget to update payment methods constantly.
Week 2: Build the core estimate builder - line items, labor, materials, taxes, markup percentages. Export to PDF via Puppeteer. This is where contractors spend the most time, so UX here compresses hours off their day.
Week 3: Mobile-first change order capture: one-tap photo upload, voice-to-text description, location stamp. Store to S3, trigger PDF generation in a Redis queue. Slack notification to the GC when a change order lands.
Week 3-4: Subcontractor management: invite links, role-based access, communication log. Contractors need to see what their subs are doing without opening five text threads.
Week 4: Onboarding flow - import template data, walk through estimate creation once, offer live demo. Build a help widget (Intercom) for stuck users.
Week 4-5: Analytics dashboard - estimates created, change orders captured, time saved per job, revenue tracked.
Week 5-6: Mobile app shell via PWA. Validate at 60%+ retention before going native.
What's hard about this build
The core technical risk is mobile-first change order capture: the flow has to be three taps or contractors won't use it, and if they don't use it, the entire value prop collapses. I'd prototype this ruthlessly with actual contractors on job sites before finalizing architecture. The second risk is PDF generation at scale - Puppeteer can bottleneck if estimates have complex nested line items; we'd need caching and async rendering. Third: integrating with contractor accounting software (QuickBooks, Xero, FreshBooks) - not MVP, but it's the differentiation that sticks. Fourth: ensuring data integrity around change orders; you're touching financial records that contractors rely on, and a sync bug causes real money problems and churn. Finally, there's the behavioral change gap. Software is 20% of this sale; the other 80% is getting them to pull out their phone instead of reaching for paper.
What's fast because of AI
I'd use Claude to scaffold CRUD boilerplate in a day instead of a week. Generating test cases for estimate calculations - markup, tax, labor rate variations - compresses testing by half. Writing UI copy (form labels, onboarding tooltips, error messages) that speaks to contractors instead of generic SaaS language saves days of iteration. Edge-case enumeration for financial calculations (what happens if a line item is zero, or negative, or has a decimal that breaks rounding) gets caught fast. Debugging contractor behavior through logs becomes faster when AI pattern-matches across a thousand estimates to find stuck onboarding funnels. Documentation and runbooks write themselves. The real win is velocity on month one; we compress uncertainty and boilerplate, leaving room to iterate on the hard part: mobile UX and retention.
How I'd hand it off
I'd ship a 15-minute Loom walkthrough of the admin panel, contractor dashboard, and mobile flow. Runbook covers provisioning new contractors, resetting passwords, handling payment disputes. You'd rotate through 30 days of pager coverage to catch bugs I missed. I'd transfer Stripe, Twilio, and AWS credentials via a secure credential store, and hand over the Linear board with documented edge cases and post-launch priorities: push notification refinement, QuickBooks integration, native iOS app.