Custom Software vs. SaaS: When Building Pays Off

Buy SaaS when your process is standard and the tool fits almost as it is. Build custom software when the process is part of what makes your business different, when your team stitches several tools and spreadsheets together, or when you pay every month for software that only almost fits. AI-assisted development has made building far more affordable: a scoped internal tool now takes days or weeks, not months.

Why are more companies building instead of buying?

According to McKinsey's latest State of AI survey, 32% of organisations now choose to build internal tools with AI coding agents instead of buying off-the-shelf software; among tech companies it is 41%. In the same survey, the share of large enterprises scaling AI agents rose from 27% to 40% within a year, while small firms stayed at 22%.

We see that gap every day. Small businesses could build; they just assume they can't. Building used to mean hiring a development team, waiting months and burning budget. Today it can mean one person who understands your process, working with an AI-powered delivery pipeline.

When is SaaS the better choice?

Standard software is the right answer more often than developers like to admit:

• The process is the same in every company, for example accounting, payroll or email.
• The tool covers your needs without workarounds.
• You don't need to connect it deeply to other systems.
• A vendor's roadmap, support and security certifications matter more to you than control.

Keep your ERP, your shop system and Microsoft 365. Replacing them rarely pays off.

When does custom software pay off?

The warning signs usually show up in day-to-day work:

• Spreadsheet sprawl: one client tracked projects, social media content and client notes across nine spreadsheets, and Monday mornings started with "where are we actually at?". One dashboard that updates itself turned a 20-minute status scramble into a 30-second glance and gave managers roughly 4 hours a week back.
• Double data entry: if data is typed into two systems, you pay for it every day. In one case that was three hours a day.
• Tools that don't fit how people work: desktop dashboards nobody can use on a phone in the warehouse or on site, so decisions wait until someone is back at a desk.
• Features you can't buy: we built our own social media tool because we couldn't find one that handled platform-specific image formats and drafted posts with knowledge of our actual projects.

Is there a middle ground?

Yes, and it is often the best option: keep your standard systems and build the layer in between. We rarely build "an AI for your company". We build narrow tools that handle one workflow and plug into your existing stack, for example a support queue that triages itself against live Shopify data, or a purchasing view that catches the one outlier distorting your forecast.

Custom web apps can also be installed on a phone's home screen as progressive web apps. They get features such as a badge with the number of unread messages, without an App Store release and without anyone having to install a new app.

What are the risks of custom software?

The honest answer: you own the maintenance, and you depend on whoever knows the code. Three things reduce that risk:

• Ownership: everything we build belongs to you, including the code.
• Documentation: a full handover, so your team or another developer can maintain and extend it.
• Predictable upkeep: fixed-price tiers for individual changes, or a monthly retainer from €690 if you want an ongoing partner.

How do you decide?

Ask three questions. Is this process a competitive advantage or a commodity? How many hours a week does the gap between your tools cost you? And would a narrow tool on top of your existing systems close that gap? If the answers are "advantage", "several" and "yes", building is worth a closer look.

FAQ

How long does it take to build an internal tool?

A scoped internal tool takes days to weeks. First quick wins are possible in 2–5 days; a complete workflow in 2–4 weeks.

What does custom software cost compared with a subscription?

Individual changes cost between €149 and €9,900 as fixed prices; larger platforms are quoted per project. Compare that with years of subscription fees plus the hours your team spends on workarounds.

Can we switch developers later?

Yes. You own the code and receive full documentation, so you are not locked in.

See examples in our case studies. Book a free call