Not everything should be custom
Identity, payments, email delivery and many back-office functions are often better purchased. Rebuilding mature commodity capability creates cost without strategic advantage.
Custom software is justified when the workflow is central to how the business wins, when existing products force damaging compromises or when integration produces a capability competitors cannot easily copy.
Look at the full operating cost
Compare subscription cost, implementation, integration, process workarounds, data ownership, vendor constraints and the internal effort required to keep the system useful.
A cheap tool that creates repeated manual work can be more expensive than a focused custom platform. A custom build without long-term ownership can be worse than both.
Make the smallest useful decision
Do not decide between a five-year platform and doing nothing. Identify the highest-value workflow, test the assumptions and build the narrowest version that can operate in the real business.
Use evidence from that first workflow to decide what should be extended, integrated or left with existing tools.