Freelance SaaS MVP Developer
Founders hire me when they need a production-ready SaaS MVP and a single owner from spec to ship. I am Ignacio (IGNAX) — Spain-born, Paraguay-based, building solo for over five years. I handle the entire stack: SvelteKit or React on the front, Node or Python on the back, Postgres for data, Stripe for billing, and one defensible feature that makes the product worth shipping at all (usually a focused AI or automation layer).
Who is this service for?
- Technical or semi-technical founders who have validated the problem and need a real product, not a Figma file.
- Indie hackers who want to launch in weeks, not quarters, and own the code afterwards.
- Agencies that need a senior full-stack subcontractor for an MVP track — white-label, NDA-friendly.
- Operators replacing a stalled Upwork engagement with someone who can finish.
If you are still validating the idea with conversations and landing pages, this is too early. Come back when at least one customer has agreed to pay.
What is included in a SaaS MVP build?
- Discovery + one-page spec, signed off before any code is written.
- Frontend: SvelteKit (default) or React + Vite, fully typed, accessible components, clean design system.
- Backend: Node.js or Python (FastAPI), REST or tRPC, deployed on Cloudflare, Fly.io, or AWS depending on cost target.
- Database: Postgres on Supabase or Neon, migrations versioned in git.
- Auth: email + OAuth, magic links, or wallet auth for crypto-adjacent products.
- Billing: Stripe Checkout, customer portal, webhook-driven subscription state, dunning.
- One differentiator built right — usually an OpenAI/Anthropic pipeline, a RAG chatbot, or an automation worker.
- Production deploy on the customer's own account. You own the code, the database, the domain.
- 14-day post-launch fix window included for non-spec bugs.
How does the build process work?
The flow is short on ceremony and heavy on shipping.
- Discovery call (free, 30 minutes). I read your notes ahead of time. We agree on the one feature that matters and the three that can wait.
- One-page spec + fixed quote. Inside 48 hours. If the scope changes, the quote changes — no surprises.
- Build. Daily commits to your repo from day one. Friday Loom video showing what runs. Slack or Discord channel, no scheduled standups.
- Ship. Deploy to your own infra accounts. You get a 90-minute handover call and a written runbook.
- Two weeks of bug fixes included on the original scope.
Working hours: Mon–Fri, 8:00–17:00 PYT (GMT-3). Weekends off. Overlap with US East 7:00–16:00 EST, with Madrid 13:00–22:00 CET.
What stack do you ship with and why?
- SvelteKit + TypeScript — fewer concepts than Next.js, smaller bundles, SSR by default. Good defaults for SEO and accessibility, which matters once the MVP becomes a real product.
- Node.js or Python — Node for tightly typed full-stack work, Python when there is meaningful AI/ML code in the loop.
- Postgres on Supabase or Neon — open data, free tier sufficient for launch, no vendor lock-in. Add pgvector for embeddings instead of a separate vector DB.
- Cloudflare Pages + Workers — global edge by default, generous free tier, zero-cold-start, integrated KV and R2.
- Stripe — non-negotiable for SaaS billing. I wire webhooks, retries, dunning, and Stripe Tax the first time.
- OpenAI or Anthropic — when AI is the differentiator I default to managed APIs over self-hosted models. Cheaper to ship, easier to debug, swap-able later.
If you are already committed to Next.js, Django, Rails, or .NET, I can match it. The same architecture pattern travels.
How much does a SaaS MVP cost?
Pricing band: $3,000–$15,000 USD (Gs 18M–92M). A focused 80–120 hour build sits in the lower half; a heavier build with multi-tenant, payments, and AI inference sits in the upper half. Hourly outside that band: $30–$70 USD/hr. PYG values approximate, recalculated quarterly. Rate as of 2026-05-27: Gs 6,136.82 / USD. For a full breakdown see how much does a SaaS MVP cost.
For agencies — white-label and subcontracting
I work as a white-label senior full-stack developer under your brand and NDA. Day-rate option: $240–$560 USD/day (derived from the hourly band). I bill weekly, deliver weekly, and never talk to your client unless you want me in the room. If your seniors are burning out on backlog, this is the cleanest fix. The same EN/ES bilingual coverage applies — useful when you have LATAM or Spain clients but an English-only team.
What does the launch look like?
I ship to your own Cloudflare, Fly.io, Vercel, AWS, or DigitalOcean account. You own the GitHub repo from commit one. After launch I run a 90-minute handover call covering deploys, secrets, billing webhooks, error monitoring, and database backups, then leave a written runbook in the repo. Two weeks of free in-scope fixes follow.
What about ongoing work after launch?
Most clients don't need a retainer; the MVP runs. When they do, I offer a 20-hour/month maintenance bucket at a 15% discount off hourly. No lock-in: 30-day rolling cancel. Feature drops after launch are priced per scope rather than open-ended retainers — see build a SaaS MVP fast for how I sequence feature work after v1 ships. For broader best practices, the Y Combinator SaaS startup guide and Stripe Atlas guides are the references I send most often.
Related case studies and articles
- AI Lead Generation Platform — SaaS built from scratch, OpenAI + Stripe + Postgres.
- Multilingual Community Platform — SvelteKit SSR, CMS-managed, multilingual.
- Build a SaaS MVP fast — the exact sequencing I use.
- How much does a SaaS MVP cost? — full pricing breakdown.
Ready to talk? Email hello@ignax.dev with your one-paragraph idea. I reply within one business day.
Working hours: Mon–Fri, 8:00–17:00 PYT (GMT-3). Weekends off. Overlap with US East 7:00–16:00 EST, with Madrid 13:00–22:00 CET.
Pricing
PYG values approximate, recalculated quarterly. Rate as of 2026-05-27: Gs 6,136.82 / USD.
For agencies
Available as a white-label senior subcontractor. Standard NDAs welcome. Day-rate option: $240–$560 USD/day depending on stack.
Email hello@ignax.devFrequently asked questions
How long does a SaaS MVP actually take?
Two to six weeks of calendar time, depending on scope. A focused MVP with one differentiator, auth, billing, and a clean dashboard fits in three weeks. Anything with multi-tenant, real-time, or heavy AI inference pushes toward six. Anything longer than six weeks should be cut into a smaller v1 and a paid v2 — that's the conversation we have in discovery.
Do I own the code and the infrastructure?
Yes, always. The GitHub repo is yours from the first commit; the database, domain, and cloud accounts are on your billing. I deploy into your accounts, not mine. There is no proprietary framework you would be locked into. If you fire me on day three, you walk away with everything that exists at that point.
What does the discovery call cover?
Thirty minutes, free, no slides. We agree on the one feature that makes the product worth shipping, the three features that can wait, the stack, the budget band, and the launch date. You receive a written one-page spec plus a fixed quote within 48 hours of that call. If the spec is not workable I will tell you in the call — that saves both of us time.
Can you work under our agency's NDA and white-label brand?
Yes. I work as a white-label senior full-stack developer for several agencies on a day-rate basis ($240–$560 USD/day). I sign your NDA, use your email if needed, and stay invisible to your client. I bill weekly, deliver weekly, and never reach out to your client unless you ask me to.
What if we already have a stack? Will you match it?
Yes — Next.js, Django, Rails, FastAPI, .NET, even legacy PHP if needed. The architecture pattern travels. The only stacks I'll push back on are ones the team won't maintain after I leave: niche frameworks, hand-rolled DSLs, or platforms with a single vendor and no escape hatch.
Do you handle payments, Stripe webhooks, and dunning correctly?
Yes, and this is where most freelance MVPs leak revenue. I wire Stripe Checkout, the customer portal, subscription webhooks, retries, and Stripe Tax. Webhooks are signed, idempotent, and replayable. Failed payments hit a dunning workflow with a Slack alert. This is non-negotiable on any SaaS I ship.
How is AI built into the product?
Default to managed APIs (OpenAI, Anthropic) over self-hosted models — cheaper to ship, easier to debug, swappable later. RAG pipelines use pgvector on the same Postgres database, no separate vector DB unless scale requires it. I keep prompts in versioned code, never in a no-code tool, so behavior is reproducible.
What happens after the 14-day fix window ends?
Most clients do not need a retainer; the MVP runs. When they do, I offer a 20-hour/month maintenance bucket at 15% off the hourly band, 30-day rolling cancel, no lock-in. Feature drops after launch are priced per scope rather than open-ended retainers — keeps both sides honest.