SaaS & Web App Development

Custom web applications and SaaS platforms: accounts, dashboards, payments, integrations. Software built around your process, shipped by one senior developer from MVP to production.

Website or web app: which one are you actually building

A website shows information: your offer, your contact details, your pricing. A web application does work: users log in, enter data, the system processes it, bills it, reports on it and enforces permissions. If your idea involves user accounts, a dashboard, recurring payments or business logic, you are building an application.

The distinction matters because it changes the architecture, the timeline and the budget. If what you need is a marketing site, see custom website development. This page is about software.

Need a business website instead? →

How much does it cost to build a SaaS MVP

Real ranges, not "it depends". An MVP with the core feature, authentication and a simple dashboard starts at $8,000-10,000 (approx. €7,400-9,300) with me. A standard MVP with payments, roles and an admin panel runs $10,000-25,000. Complex systems with heavy integrations go beyond that, and I say so before we start, not after. Agency-built MVPs are commonly quoted in six figures, which is exactly the overhead gap a senior solo developer removes.

What drives cost is specific: authentication and roles, payments (especially subscriptions), third-party integrations, and reporting dashboards. The winning strategy is almost always a tight MVP first, then building based on how real users behave instead of guesses.

What I build

Complete systems: registration and login (including Google sign-in), roles and permissions, live dashboards, one-off and recurring payments through Stripe, email and push notifications, and API integrations with the tools you already run.

Everything is TypeScript with tests, on a boring-on-purpose stack: React and Next.js on the front, Node.js and PostgreSQL behind. These are the technologies the biggest web products run on, and they are standard enough that any future developer can take the project over. No lock-in to me.

Proof: products I have shipped

Fennaro: a dog-matching app I built solo, end to end. Accounts, geographic matching on PostGIS, chat, moderation, GDPR compliance and an installable PWA, live in production. FlowMate: a SaaS email platform where I learned production architecture the hard way: secure auth, async processing, AI integrations. BestEats: a food-ranking platform live in Portugal, where I ship code under senior code review.

I write about these builds publicly, including the mistakes. If you want to know how I think before hiring me, read the Fennaro story: it covers the decisions no portfolio screenshot shows.

How I built Fennaro: the full story →See all projects →

How delivery works and how long it takes

We start from the problem, not the feature list: what the system must accomplish, who uses it, what is genuinely essential in version one. You get an MVP scope with a fixed quote, split into stages so you always know what you are paying for. A typical MVP ships in 4-8 weeks with weekly progress updates you can react to.

After launch you are not stranded: the code is documented, deployed on infrastructure you own, and monitored, so I know about errors before your users report them. We grow the product in stages based on real usage.

Technical Stack

Frontend

React 19, Next.js 15, TypeScript. Fast, SEO-friendly SaaS frontends with reliability as features grow

Backend

Node.js, PostgreSQL (Supabase, Prisma). Scalable, multi-tenant data models keeping customer data separate and secure

Authentication

Clerk or NextAuth for secure user management with social logins and OAuth

Payments

Stripe subscriptions and webhooks. Automating the full billing lifecycle

Real-time & Deployment

WebSockets or SSE when required. Vercel with managed databases for predictable performance and scaling

SaaS and web app questions, answered

How much does it cost to build a SaaS MVP?
With me: from $8,000-10,000 for a core-feature MVP with auth and a dashboard, $10,000-25,000 with payments and roles (roughly €7,400-23,000). Agency cost surveys put the median agency-built MVP around $120,000, which is the overhead you are not paying when you hire the developer directly.
How much does it cost to build a SaaS app?
A full production SaaS beyond MVP stage typically lands at $25,000+ depending on integrations, compliance and scale needs. I quote in stages, so you fund the MVP first, verify real demand, and only then invest in the full build. Nobody should pay full-product money on a guess.
How long does it take to build a SaaS MVP?
A focused MVP ships in 4-8 weeks with me. Typical agency timelines run 8-16 weeks, and the difference is layers: no handoffs between designer, PM and developer. The biggest real-world delay is unclear requirements, which is why week one is scope work, not code.
Should I hire a freelancer or an agency to build my SaaS MVP?
For MVPs and small-to-mid systems, a senior freelancer is usually the better deal: direct communication and no agency overhead. For very large systems a team makes sense, and I say that in the quote instead of overselling. Judge any developer by shipped products, not slide decks. Mine are public.
What features does a SaaS MVP actually need?
The one core feature that proves your idea, plus login, a minimal dashboard and a way to pay you. That is usually it. Every extra feature before real users arrive is money spent on a guess. The point of an MVP is to make the next spending decision with evidence.
How much do freelance SaaS developers charge?
Marketplace listings (Upwork, Arc) show senior SaaS developers at $50-120 an hour, with Poland-based seniors at the lower half of that for equal skill. I price fixed per stage instead of hourly: you know the number before work starts, and scope creep is my risk to manage, not your invoice surprise.
What is a realistic SaaS timeline for a non-technical founder?
Plan for 4-8 weeks of build after about a week of scope definition, then 2-4 weeks of real-user feedback before deciding the next stage. The classic founder mistake is skipping the feedback window and ordering more features immediately. The system I hand over is built to be extended, so waiting costs nothing.
What is the difference between an MVP and a full SaaS product?
An MVP proves that people want the core of your idea; a full product earns money at scale. The MVP has one polished core flow; the full product adds roles, billing edge cases, admin tooling and integrations. Funding them as separate stages protects you from building the second one for users who never arrive.
How much does web app development cost in Poland?
Complex custom web applications from Polish teams are quoted at roughly $25,000-100,000+ in 2026, still well under Western European agency pricing. As a solo senior developer I sit below team pricing for MVP-scale work: $8,000-25,000 covers most first versions, with the same stack and standards.

Have a product in mind?

Describe the problem your product should solve. I reply within a day with an honest MVP scope, a price band and the questions that sharpen the idea.

Describe your product