Defining technical specifications

Technical specifications explain how a product will achieve the behaviors described in the functional spec. Using the same fitness app example, if the functional spec says “the app must display workout progress in real time,” the technical specification would define how this happens: which sensors capture data, which API updates the progress bar, what refresh rate ensures accuracy, and what database stores results.

These details form the engineering blueprint. They outline architecture, integrations, frameworks, and constraints. For instance, “the app must sync data every five seconds using Bluetooth Low Energy” or “the backend must support up to 10,000 concurrent users.” Clear technical specifications align teams on feasibility, performance, and security before development begins.

By separating user expectations from implementation details, teams can validate both product vision and system reliability without mixing goals.^[1]