In this episode, Toby and Krisztian share their hands-on experiment building a real group management app using Claude Code and agentic engineering. Toby spent roughly a month's worth of hours prompting Claude to build a cross-platform mobile and web app with Expo, a Node/Express API, Postgres on Scaleway, Hanko authentication and Terraform infrastructure — all without looking at the code. They discuss what worked surprisingly well, what fell apart, the token costs, how agentic engineering compares to managing juniors, and what they would do differently next time.

Chapters

0:00 Introduction: the experiment

1:15 Why Expo for cross-platform mobile and web

2:54 The architect document approach

5:50 How the initial prompt and brainstorming worked

7:45 Not looking at the code

9:05 Context7: giving Claude access to latest API docs

10:35 First pass results

12:46 API and database quality: better than expected

14:40 UI issues: the weak spot

17:20 The bug list testing session

24:23 How sub-agents and parallel work played out