What really separates custom software from SaaS?

One question: who adapts to whom? Custom software fits your processes, your business rules and your vocabulary. Standardised SaaS asks you to adapt the way you work to predefined features. Everything else — price, timelines, maintenance — follows from that initial trade-off.

When is SaaS the right choice?

When the need is narrow, the team is small and speed matters most. An invoicing tool, a CRM for three salespeople, a shared schedule: at 30 or 50 euros a month, a subscription does the job perfectly. Commissioning custom development for something that already exists as a subscription is the most common way to waste a digital budget.

What signals that it is time to go custom?

The day you spend more time working around your tool's limits than using it. In practice: daily Excel exports to compensate for a missing report, double data entry between two systems, or a process explained to every new hire as we do it this way because the software cannot do otherwise. Those workarounds carry a payroll cost almost nobody quantifies.

What risks come with custom software?

Three mainly. Vendor lock-in, if the code and access credentials are not contractually yours. Scope creep, when every meeting adds a feature. And unbudgeted maintenance, which turns a good tool into technical debt within two years. All three are handled in the contract, not afterwards.

Custom software or SaaS: how to decide

Q: Which one costs less over time?

It depends on user count and time horizon. SaaS has a low entry cost but accumulates: 20 users at 150 dollars per month is 180,000 dollars over five years. Custom development costs 40,000 to 80,000 dollars upfront plus 5,000 to 10,000 dollars of annual maintenance, so 65,000 to 130,000 dollars over the same period. The tipping point generally sits around 15 to 20 users on a five-year horizon.

Q: Is no-code a credible alternative?

Often, yes. No-code or low-code development is three to four times faster than classic development, at a cost 30 to 50% lower. For many SMEs needing a specific business tool without extreme technical complexity, it is currently the most balanced compromise between a standard subscription and full custom development.

It is the most common trade-off in the projects brought to us, and the one where a wrong call costs the most: should you subscribe to an existing tool or have your own built?

The question really reduces to one thing: who adapts to whom? Custom software fits your processes. SaaS asks you to adapt yours. Everything else — price, timelines, maintenance — follows from that.

The calculation nobody runs

SaaS always wins at first glance, because you are comparing a monthly subscription to a development budget. A small monthly figure against a large invoice, and the conclusion looks obvious.

It is far less obvious over five years.

For an SME with 20 users at 150 dollars per licence per month, the subscription comes to 180,000 dollars over five years. Custom development costs 40,000 to 80,000 dollars upfront, plus 5,000 to 10,000 dollars of annual maintenance, so 65,000 to 130,000 dollars over the same period (CyberPerformance).

The tipping point generally sits around 15 to 20 users on a five-year horizon. Below that, subscription is unbeatable. Above it, the question deserves serious consideration.

Two nuances usually missing from this kind of comparison:

SaaS prices go up. Your five-year model must include annual increases, not freeze the price on the day you signed.
Custom software is an asset. You are not renting, you own it. Provided the contract says so explicitly, which is not always the case.

When SaaS is the right call

Let us be clear: in most cases SaaS is enough, and it is what we regularly recommend to clients who came to us asking for custom development.

A subscription makes sense when the need is narrow, the team small, and speed the priority. An invoicing tool, a CRM for three salespeople, a shared schedule: at 30 or 50 euros a month, there is no debate.

Commissioning custom development for something that already exists as a subscription is the most common way to waste a digital budget. Nobody should pay to reinvent invoicing software.

The signal to watch for

There is a precise moment when the balance tips, and it is easy to spot:

The day you spend more time working around your tool’s limits than using it.

You recognise that moment by very concrete symptoms:

The daily Excel export to produce a report the software cannot generate.
Double data entry between two systems that do not talk to each other.
The repurposed field, where delivery times get typed into the “comments” box for lack of a proper one.
The ritual sentence to every new hire: “we do it this way because the software cannot do otherwise.”

Those workarounds carry a real payroll cost almost nobody quantifies. Two hours per person per week across a team of ten is a half-time role every year spent compensating for an unsuitable tool.

It is one of the signals we detail in our article on the signs it is time to go digital.

No-code, a serious third path

The debate is too often framed as binary. It no longer is.

No-code or low-code development is three to four times faster than classic development, at a cost 30 to 50% lower (Ecma-Tech).

For an SME needing a specific business tool without extreme technical complexity — case tracking, field service management, approval workflows — it is currently the most balanced compromise. You get your business rules without paying for full custom development.

Its limits show up with volume, complex integrations and performance requirements. But they arrive later than people expect.

The three risks of going custom

Choosing custom is not risk-free. Three risks recur, and all three are handled in the contract, not after delivery.

Vendor lock-in. If the source code, server access and documentation are not contractually yours, you have not bought software, you have rented a relationship. Require it in writing.

Scope creep. Every meeting adds an idea and the budget drifts by 40%. A written, dated scope with a clear procedure for additions solves it.

Unbudgeted maintenance. Custom software without maintenance becomes technical debt within two years. Plan 10 to 15% of the initial cost per year, from the first quote.

Our approach

At DIGABLO, we start by checking whether an existing SaaS does the job. When it does, we say so.

When it does not:

Process scoping before any technical choice, because the right tool depends first on how you work.
A costed five-year comparison between subscription, no-code and full development.
Ownership of code and access, written into the contract.
A dated scope, with an explicit procedure for changes.
Maintenance priced in the quote.

Torn between subscribing and building? Let’s talk about your project: we will look at your processes and tell you frankly which side you are on.