Buy vs. build is now also a UX decision, especially in enterprise

Patrick Neeman argues that coding agents make internal tools cheap to build but not to own, so designers should weigh in before a team decides to buy or build.

Patrick Neeman, a user experience designer, writes in UX Collective that product managers and finance have long decided whether to buy software or build it, with designers inheriting the result. Coding agents now make an internal tool look like an afternoon's work, while a purchased tool brings a vendor's model, roadmap and data model. He argues that the real question is where the complexity lands: in the team's code, in a vendor's roadmap or on the users.

• He budgets 30 per cent of the upfront build cost every year for upkeep. In his example, a tool two people build in two weeks costs $45,600 over three years, against $18,000 for a $20-a-seat subscription for 25 people.
• To measure the gaps between tools, he follows one real task across every system it touches and logs each switch and each retyped value.
• Inside ChatGPT, Slack or Teams the host sets the rules, and an inline ChatGPT card gets at most two actions. He designs each card for one job, with a handoff to the full application.
• Because AI models are retired, he keeps 20 to 30 real tasks with known good outcomes, including cases where the right response is to decline. He reruns them after every model or vendor release.

A product or design team weighing an internal tool built with AI can name its maintainer and its yearly upkeep budget before it ships. Neeman writes from his own experience and published research, not from one team's measured account.

Derived by Working Surface from the article; more in the Playbook. Source line: Build is cheaper now, but the yearly upkeep never shows up in the business case.

24 October 2026: teams keep the time AI saves only when they decide in advance what an AI agent may do alone, what waits for a person and who maintains what it builds.