Build vs Buy Software: How to Make the Right Decision for Your Business

Most businesses get the build vs buy decision wrong — in both directions. Some build when they should buy, committing to a custom project before they understand their own workflows well enough to spec one. Others keep buying, accumulating SaaS subscriptions and workaround spreadsheets long past the point where a custom system would have been more practical and cheaper.

The decision is not fundamentally about technology. It is about process fit, total cost over time, and who owns the risk when something changes.

When to buy (and keep buying)

Most business functions have good off-the-shelf solutions. Email, accounting, CRM, HR, project management — for standard workflows, commercial software is almost always the right answer. The development overhead is not worth absorbing when a well-maintained SaaS product handles 95% of what you need and improves continuously.

• Your workflow fits the product without significant workarounds or hacks
• The vendor's feature roadmap will solve the remaining gaps within a reasonable timeframe
• Per-seat cost is proportionate to the value you extract from the tool
• Data portability and integration capabilities cover your requirements
• The risk of vendor lock-in is acceptable for this particular function
• Your usage of the tool is likely to stay broadly standard — not diverge from what the product was designed for

When to build custom

The signals that point toward custom software are usually consistent. If you are asking this question, you have probably encountered at least one of them already.

• You are paying for a SaaS product and spending significant time working around it — export, reformat, re-enter elsewhere
• Your process requires a combination of features that no single product offers
• You need integrations with bespoke, legacy, or proprietary systems that SaaS tools cannot reach
• Per-seat costs have reached — or will reach within 24 months — the cost of a custom build
• You need to own and control the data: vendor cloud storage is not acceptable for compliance, competitive, or security reasons
• Your workflow is specific enough to your business that it constitutes a genuine competitive advantage worth protecting

The real cost of "good enough" SaaS

Per-seat subscription cost is only part of the calculation. The hidden cost of software that does not quite fit is the labour cost of working around it.

If your team spends four hours per week adapting outputs from a SaaS tool into a form your process actually needs — manual exports, reformatting, re-entry into another system — that is four hours per week at your average labour rate. At €35/hour, that is €140/week, roughly €560/month, and over €6,700/year.

Over three years, that is more than €20,000 in extra labour costs — on top of the subscription fees — for software that was never designed for your workflow. Most custom builds for SMEs cost less than this combined total. The break-even calculation is often simpler than it appears.

A practical decision framework

Five questions worth working through before committing to either path:

• Can you map your core workflow clearly enough to write a spec? If the answer is no, buy first and use the experience to understand your own process before building.
• What is the honest three-year total cost of the SaaS option, including seat fees, workaround labour time, and any adjacent tools you need to fill the gaps?
• What is the vendor risk? If they raise prices significantly or discontinue the product, what is the recovery cost?
• Does this workflow give you a meaningful competitive advantage? If yes, owning it as proprietary software is worth more than licensing it from a vendor.
• How much of your process is genuinely standard versus specific to how your business operates? Standard workflows belong in commercial software. Specific ones belong in custom builds.

The hybrid approach

The build vs buy decision is rarely all-or-nothing. Most practical setups use commercial software for standard functions — email, calendar, accounting, basic CRM — and custom software for the workflows that are specific to how this particular business operates.

The custom system typically integrates with the commercial tools: pulling data in, processing it according to business-specific rules, and pushing results back out. This gives you ownership and control where it matters, without rebuilding things that are already well-solved by the market.

The sign that you have reached the right balance: your team stops spending time working around the gaps and starts spending time on the actual work.