SaaS MVP development with auth, billing and tests built in
I build SaaS MVPs end to end: the data model, auth, Stripe billing, multi-tenancy, automated tests and deploys. My largest is OnOffDeals, a real-estate deal-analysis SaaS where I am the sole developer and architect across roughly 20K lines of code. You work with one person who owns the whole stack and can explain every part of it.
- OnOffDeals: ~20K lines, sole developer
- 311 automated tests on one backend
- Live Stripe billing with usage metering
What goes into a SaaS MVP I build
An MVP still has to take money, keep each customer’s data separate and hold up when real users arrive. I build those foundations first, then the features that make your product different, so auth and billing are not rebuilt after launch. Everything below is something I have shipped in production, not an item on a wish list.
- Clerk + JWT auth with role-based access and role-gated routes
- Stripe subscriptions, trials, coupons and a webhook-driven state machine
- Per-plan usage metering with overage
- Multi-tenant data with row-level security and invite-based billing
- Automated tests on the logic that is expensive to get wrong
- Deploys on Vercel and Railway
OnOffDeals: a SaaS built by one developer
OnOffDeals is a React 18 SPA on Vite backed by a fully async FastAPI, MongoDB and Redis API with 16 routers, 20 domain services and 311 automated tests. Its core is a valuation and underwriting engine I wrote from scratch: comparable-sales selection, ARV, MAO, flip profit, cap rate, cash-on-cash return and DSCR. Anthropic Claude runs inside the app as a deal coach with prompt guardrails and validated structured output, and versioned market caching keeps third-party property-data costs viable under rate limits.
Multi-tenant SaaS architecture
For a SaaS forecasting platform I designed a nine-table relational model with row-level security, so tenant isolation is enforced by the database and not only by application code. Billing is invite-based, Redis handles caching, and end users and administrators get separate apps, which keeps admin-only features out of the customer-facing build. Decisions like these are cheap at the MVP stage and painful to retrofit later.
Product decisions, not just code
I also build and run my own product. Gurukin is a free, ad-free learning platform I created and develop alone: 758 practice questions for the Claude Certified Developer – Foundations exam, a fresh 53-item mock exam every sitting, and a 100-day JLPT N5 roadmap whose progress saves in the browser with no account needed. Content is AI-drafted, then human-reviewed and fact-checked. Running a product myself shapes how I scope yours: launch the smallest useful version, then improve it.
Rates from $20/hour
Hourly for open-ended work, fixed price for defined projects. The first call is free and there's no obligation.
Frequently asked questions
How long does SaaS MVP development take?
It depends on scope, so I don’t quote a timeline before we have one. On a free 30-minute call we agree on the smallest version worth launching, I break it into milestones, and you get a fixed-price quote for that defined scope, or an hourly arrangement if the scope is still moving.
Which stack do you use for a SaaS product?
Usually React 18 with Vite and Tailwind on the front end, FastAPI with MongoDB or PostgreSQL plus Redis on the back end, Stripe for billing and Clerk or JWT for auth, deployed on Vercel and Railway. I also work in Next.js and Django when a project is already built on them.
Can you take over a SaaS codebase someone else started?
Yes. At Podiam AI I joined a production Django and Next.js codebase and split one reported bug into three independent defects, fixing each with its own test. I reproduce a problem, isolate it and write up the cause before I change anything.
What does it cost to hire you for a SaaS build?
My rates start from $20/hour, and I give fixed-price quotes for defined projects. You can hire me directly or through Upwork, where I hold 100% Job Success across 11 jobs. I work remotely from Delhi, India, and overlap US working hours.