Build vs Buy:
Should You Build Custom Software?
Custom software gives you exactly what you need. Off-the-shelf gives you something that works today. This guide helps you make the right call for your business, budget, and timeline.
Quick Take
Build custom software when the functionality is your competitive advantage or when no off-the-shelf product fits your core workflow without heavy customisation. Buy when the problem is well-understood, standardised, and not differentiating - accounting, CRM, email, project management. The hidden cost of building is ongoing maintenance; the hidden cost of buying is vendor lock-in and workarounds for features that do not quite fit.
Signs You Might Be Facing This Decision
You are using spreadsheets or manual processes for something that clearly needs a proper system
Your current SaaS tool works for 80% of your workflow but the other 20% is painful
You have been quoted a custom development price and are not sure if it is worth the investment
Your competitors have custom tooling that gives them an edge you cannot match with off-the-shelf
The Decision Framework
Answer these questions honestly. The right choice depends on your specific situation, not general rules.
Is this functionality your competitive advantage?
Yes → Build. If the software IS your product or directly enables what makes you better than competitors, owning it gives you control, speed of iteration, and differentiation. No → Buy. If it is a supporting function (HR, accounting, email), buy the best tool available and focus your engineering effort on what matters.
Does an off-the-shelf product cover at least 80% of your needs?
Yes → Buy (probably). Adapt your process to fit the tool rather than customising the tool to fit your process. The 20% gap is usually cheaper to work around than the cost of building and maintaining everything. No → Build. If you would need to heavily customise an off-the-shelf product, you end up with the worst of both worlds - vendor dependency AND custom code.
Can you maintain custom software long-term?
Yes → Build is viable. You need developers on staff (or on retainer) to maintain, update, and fix custom software indefinitely. Factor in security patches, dependency updates, and feature requests. No → Buy. If you cannot afford ongoing engineering, custom software becomes a liability, not an asset.
How urgently do you need it?
Yesterday → Buy. Off-the-shelf solutions are available immediately. Custom software takes months. If time-to-market is critical, start with a SaaS tool and plan a custom build for later if needed. Can wait 3-6 months → Build is viable. But be realistic about timelines - custom software projects typically take 1.5-2x the initial estimate.
Hidden Costs Most People Miss
Hidden Costs of Building
- • Ongoing maintenance (security, updates, bugs)
- • Infrastructure and hosting costs
- • Developer turnover and knowledge loss
- • Opportunity cost of engineering time
- • Feature requests that never end
Hidden Costs of Buying
- • Vendor lock-in and data migration costs
- • Annual price increases (SaaS creep)
- • Workarounds for missing features
- • Integration costs with other systems
- • Loss of control when vendor changes direction
When to Get Expert Input
- ✔ You are committing significant budget and need an independent assessment of build vs buy
- ✔ You are non-technical and cannot evaluate vendor claims or development proposals objectively
- ✔ You have already started building and suspect it is costing more than buying would have
- ✔ You are outgrowing your current off-the-shelf tool and wondering if custom is the right next step
Need Help Deciding?
We help businesses evaluate build vs buy objectively. No agenda - we are just as happy recommending a SaaS tool as building custom software.