Building a SaaS Platform: Costs, Process and Choices

What does building a SaaS platform actually mean?

SaaS stands for software-as-a-service: software you do not sell per copy, but rent out per month or year. Building a SaaS platform means having one application developed that many customers use at the same time, each with their own account and data, but all on the same codebase.

That last part is the whole difference with ordinary custom software. With custom software you build something for one organisation. With SaaS you build something once and sell it to a hundred companies, without installing it a hundred times. If you want a sharper sense of the difference between the two, read our piece on custom software development.

A SaaS is a good choice if you solve a problem that more companies than just you have, and if customers are willing to pay for it monthly. That recurring revenue is the heart of the model: you build once and keep earning for years, provided the product keeps working and grows along.

It is not a good choice if what you really need is a single internal tool for your own company. Then you pay for complexity you will never use. More on that further down, in the section on when you are better off not building a SaaS.

• You solve a problem that more companies than just you recognise.
• Customers are willing to pay for it monthly or yearly.
• One codebase serves all your customers, not one installation per customer.

What does building a SaaS platform cost?

Honest answer: it depends heavily on scope. In the Dutch market, a first usable version, an MVP, roughly runs from fifteen thousand to forty thousand euros. A fuller platform with multiple user roles, payment integrations and connections quickly heads toward a hundred thousand euros or more.

On top of the build cost, count on recurring costs. For hosting, maintenance and small changes, fifteen to twenty percent of the development budget per year is a realistic rule of thumb. A SaaS is never finished: it runs, so it has to be kept up.

The good news is that the model is meant to pay those costs back. If ten customers each pay fifty euros a month, that is six thousand euros a year against it. Do that sum honestly before you start. For the broader logic behind software costs, we have a separate article on the cost of custom software.

Most budget overruns come not from expensive hours but from scope creep: features added along the way. A good discovery phase up front, in which you get clear on what has to be in the first version and what can wait, is the best protection against a bill that ends up twice as high as expected.

How long does it take and how does the build process work?

An MVP of a SaaS is usually built in eight to twelve weeks. A fuller platform with more roles and integrations runs closer to three to five months to the first production version. After that it does not stop, but that is precisely the intent.

We build in short iterations. Every few weeks you see working software instead of a document full of promises. That way you notice early whether an assumption holds, and course correction stays cheap. Often you are best off starting small and tightly scoped; we describe that approach in our article on building an MVP.

If one thing kills a SaaS, it is not the technology but the absence of validation. Most failed SaaS products were technically fine, only nobody wanted to pay for them. So talk to paying customers before you start a big build, not after.

After launch, you watch how the platform behaves in practice and move on to the next step. A SaaS that stalls after delivery ages fast; one that keeps moving with what customers need grows more valuable over the years.

Multi-tenant, scalability and the tech without jargon

The term you often hear is multi-tenant. In plain language: one system that serves many customers, with each customer's data kept neatly separate. Like building an apartment block instead of a hundred separate houses. That saves maintenance, but demands careful choices from the start about how you keep that separation watertight.

Scalability means the same platform works fine at ten users and at thousands. You do not arrange that afterwards, but by accounting for growth in the design. A SaaS that only runs smoothly with a handful of users is not a platform but a demo.

Because you manage customer data, security is not a side issue. If you work with personal data, the requirements of the Dutch Data Protection Authority are a good starting point before a single line of code exists. For the subscription and billing part you rarely build your own; the Stripe Billing documentation shows well what is involved there.

Increasingly there is an AI component in a SaaS, for example to process documents or guide users through a process. Whether that makes sense depends on the problem. We wrote about it separately in our piece on integrating AI into business software.

When you are better off NOT building a SaaS platform

Honest advice belongs here too, even when it talks us out of the work. If what you really need is a tool for your own company, build a plain internal application and not a multi-tenant platform. Building a SaaS for one customer is not a platform, it is an expensive way to make one customer happy.

Do not build without validation either. If nobody has committed to paying yet, the first step is not code but a few honest conversations with the people who are supposed to buy it later. An idea nobody signs up for does not get better by building it.

And check whether it already exists. If an existing SaaS package does ninety-five percent of what you want at a fair monthly price, use it. Building yourself what is already on the shelf is rarely worth it.

Finally, a SaaS demands involvement from your side: someone has to make decisions and be available. Without that internal owner, even a strong technical team stalls. If you are unsure about the supplier side, read how to choose a software agency.