What is a tech stack?
A tech stack is the full set of software and services a business uses to run its operations, such as email, accounting, CRM, scheduling and file storage, along with the connections between them.
The phrase comes from software development, where it describes the languages and frameworks a product is built on. For a service business, it simply means the tools you run on. A typical stack might include Microsoft 365 or Google Workspace, QuickBooks Online, a CRM, an industry system such as Karbon or Housecall Pro, a phone system, an e-signature tool and a handful of integrations.
Mapping the stack is a useful exercise. List every tool, what it is used for, who owns it, what it costs, and which other tools it exchanges data with. A simple diagram often reveals duplicate tools, manual copying between systems, and core processes that depend on a single spreadsheet. It also shows where a change in one tool might break something elsewhere.
A good stack is not the newest or the largest. It is one where each tool has a clear job, important data has a home, and the connections are documented. Before adding software, ask whether a tool you already pay for can do the job with a settings change. Often it can.
Example
For example, a 20-person physical therapy practice maps its stack and finds patient intake happening in three places: a web form, the EHR's portal and paper forms scanned to a shared drive. The practice standardizes on the EHR portal, retires the web form subscription, and documents which staff role owns each remaining tool.