William Imoh, founder of Hackmamba, shows Claire Vo the native Norwegian-practice app he built with Codex and discusses how agents assist his company. This is a founder’s account, not an independent assessment of the app or a language-learning study.

Start with the missing experience

  • After a 1,000-day Duolingo streak, Imoh says he still couldn’t hold a Norwegian conversation. People often answered his hesitant Norwegian in English, removing the practice he needed.
  • He wanted a patient conversation partner that stays in Norwegian, corrects mistakes and adapts to his level. An earlier hackathon attempt produced a poor experience.
  • He knew web development and had worked as a product manager, but had never written Swift. He chose Swift for iOS and Kotlin for Android rather than limiting the product to languages he knew.

Specify the interaction, then revise the design

  • His initial Codex prompt described a real-time voice conversation, a pulsating orb, captions, minimal controls and warm autumn colors. He specified a real-time speech model for low-latency turns.
  • The first design came back in dark mode; he rejected it and asked for light, warm colors. The working brief needed feedback, not just more adjectives.
  • Vo argues that design vocabulary and a clearly described user journey matter more here than a generic instruction to make a polished app.
  • In the live demonstration, Imoh asks the tutor to switch to English. It refuses and keeps the conversation in Norwegian; he reviews its correction of a grammatical mistake afterward.

Costs and operating boundaries

  • Imoh says the real-time voice sessions are expensive, then gives conflicting estimates for a 30-minute session. Treat the costs as a rough personal report, not a verified price per user.
  • He describes separate workspaces for business operations, sales and growth, with a weekly start/stop/continue brief. He also uses role-based agents for company functions; this post does not recommend the particular agent product discussed in the interview.
  • His access policy is strikingly permissive: he says his agents can reach most of his work tools, including browser and computer-use actions, while excluding bank write access and customer data. That is a security risk to evaluate, not a default configuration to copy.
  • When an agent fails, he restarts, specifies the steps and asks for a review. He worries that relying on agents across many simultaneous sales and hiring tasks makes the company vulnerable if they stop working.

“I wanted to speak Norwegian … to something first that wouldn’t judge me and something that would correct me.” — William Imoh