When should enterprises build instead of buy?

Payroll, general ledger, procurement, expenses — these are solved problems, and solving them again is a poor use of capital. The default answer for commodity processes is and remains a standard system.

The difficulty is that this sensible rule is applied to everything, including the processes that make a company different from its competitors. A specialist insurer's underwriting judgement, a manufacturer's planning logic, a logistics operator's exception handling: these are not commodity processes, and forcing them into a standard product means either changing the business to fit the software or paying to bend the software back.

Signals that you are already building

Many organisations are building custom software without calling it that. The signals are consistent.

• Configuration and customisation cost more than the licences.
• Upgrades require a project because previous customisations must be reapplied.
• The real process runs in spreadsheets alongside the system, because the system cannot express it.
• The vendor roadmap is a recurring topic in your operational planning.
• A consultancy is permanently engaged to keep the product aligned to your business.

Heavy customisation is a custom build with worse ownership and a licence fee attached.

A workable rule

Use standard systems for systems of record: the ledger, the ERP, the CRM, the HR platform. Build the layer of operational software that sits on top — the workflows, decision support, portals and internal tools where your process is the advantage — and integrate it properly with the systems of record underneath.

This is not a compromise position. It is how the strongest operators already run: a stable core they do not touch, and a fast-moving layer above it that reflects how they actually work. What AI-native development changes is the cost of maintaining that upper layer, which is what made the pattern impractical for mid-sized companies until recently.