Should I build or buy AI?
By the InTheory team · Updated November 2026
Most service businesses should buy. Start with AI features in software you already use, then add an off-the-shelf tool, and build custom only when your process is truly distinctive and the value clearly covers ongoing maintenance. A custom build makes sense for perhaps one workflow, not as a default.
The case for buying
Vendors such as Microsoft, Google, HubSpot and many practice management providers now include AI features. Buying is faster, cheaper to start and someone else maintains it. The trade-offs are less control, features you may not need, and dependence on the vendor's roadmap and data terms. Read those terms before turning anything on.
When building is worth it
Building fits when your workflow gives you an edge and no product handles it well, such as a pricing method unique to your firm or a complex estimate built from your own historical jobs. It also fits when you need to connect several systems in a way no single vendor supports.
Count the full cost: design, testing, hosting, usage fees, monitoring and someone to fix it when an underlying service changes. A middle path, assembling bought tools with Zapier, Make or n8n, often covers most needs. InTheory is vendor-neutral, and sometimes the right decision is to avoid a new build.