A figure seen from behind, the back of the head showing, adjusts a row of small brass sliders and knobs clamped to the edge of a workbench, and each turn changes the shape of a working model that a small robot is still assembling at the far end of the bench, the whole scene drawn with wide empty margins on every side.

The Pragmatic Engineer

Design Engineering with Maggie Appleton

Gergely Orosz with Maggie Appleton · 23 September 2026

Company story · prototyping · Evals before the build

Takeaway

Maggie Appleton, a research engineer at GitHub, no longer reads the code AI agents write for her prototypes and writes a spec saying how the agent will check its work.

Summary

Gergely Orosz, who writes the engineering newsletter The Pragmatic Engineer, interviewed Maggie Appleton on his podcast. Appleton is a staff research engineer at GitHub Next, GitHub's research group, where she builds prototypes of new ways for engineers to work with AI. The show notes describe how her design process has changed now that coding agents build her prototypes.

Key points

Appleton has a coding agent add sliders and colour pickers to each prototype, so that she can adjust colours, sizes and animation speed while it runs.
She no longer reviews the code in agent-written changes, a practice the show notes limit to prototypes. Once she knows what to build, she writes a detailed spec that lists how the agent will verify its work.
She finds planning with agents tiring. An agent asks multiple-choice questions "a hundred times over", and by question 20 a person starts accepting its recommended answer by reflex.
She wants new shared documents and tools in which people and agents can work together, and calls finding them "a really hard challenge".

Implication

Appleton limits unread agent code to prototypes, so a team adopting the practice has to say which of its builds are prototypes. That scope rule is an inference and is not Appleton's claim.

Suggested actions

Product

Before an agent builds a prototype, write a spec that lists how the agent will verify each part of its work.

Design

Have the agent add sliders and other live controls to a prototype, so that its colours, sizes and motion can be adjusted while it runs.

Derived by Working Surface from the article. Source line: Trying to find artifacts that allow us to meet in the middle and create stuff together is a really hard challenge.

Source issue

26 September 2026: when agents can finish whole tasks, teams redesign the work, the checks and the roles around them.