Two of today's pieces describe teams changing how they build, because AI agents have made building cheaper. The third says the hard part has moved from making a prototype to choosing one.
Greg Unrein, Josh Jensen and Christopher Wildman (30 Sep · 01) write on Dropbox's engineering blog about Reclaim, a calendar assistant that Dropbox owns. Reclaim uses AI to find and move time for tasks, habits and meetings. Users wanted to state scheduling goals in their own words, but an AI model can read a loose request in several ways, some of which change other people's calendars. The team made its AI agent use the same checks that people and the automatic scheduler already used. Each proposed change first appears in a preview of the calendar for the user to confirm. The authors explain the care: "Calendar changes carry real weight because time is precious and scheduled events often involve other people."
Gergely Orosz (30 Sep · 02), who writes the newsletter The Pragmatic Engineer, explains why Shopify is dropping React Native. Shopify, the e-commerce platform, began moving its mobile apps to React Native in 2020, a framework that runs one shared codebase on both iOS and Android. As late as January 2025 it called the move a success. In September 2026 it announced that it will rebuild every app natively, because AI coding agents now write, port and test code for each platform cheaply enough. A shared test suite checks that both versions behave alike. The rest of the article is for paying subscribers, and this account comes from its open part. Shopify's head of engineering, Farhan Thawar, told Orosz: "Basically, React, as the shared language, is now replaced by the English language, thanks to LLMs."
Paige Costello (30 Sep · 03), vice president of product at Figma, writes on the company's blog about what AI changes in building a product. A team can now turn a prompt into a clickable prototype within hours, but the prototype cannot show whether its direction is the right one. She asks: "Is this direction the best or just the first?" She advises trying several directions and comparing them side by side. She also advises building out the states a single prototype leaves out, such as a booking flow with no free slots. The post was published on 24 September and recommends Figma's own tools at each step.
In each piece, cheap building moves the effort somewhere else. Dropbox puts it into one set of checks and a preview the user confirms. Shopify puts it into a shared test suite that both apps must pass. Costello puts it into comparing several directions before committing to one. Salesforce's Agent Designer follows the same idea: an engineer approves a design before any file is written (28 Sep · 08).
All three pieces are companies describing their own products or choices, and Figma's post recommends its own tools. The Shopify account comes from the open part of a paid article, and no piece reports whether the new approach worked.
Dropbox's engineers sent every AI agent change in Reclaim, their calendar assistant, through the same checks of scheduling rules that people's changes pass, and let users preview it first.
Shopify is rebuilding its React Native mobile apps as separate iOS and Android apps, because AI coding agents have made building each feature twice cheap enough.
Paige Costello, vice president of product at Figma, argues that AI makes prototypes quick, so the hard work moves to choosing a direction, finishing the product and making it distinctive.