Most people practise coding interviews alone and in silence, but real interviews happen out loud. Prep is an Electron IDE where you talk through your approach and the copilot hears you, sees your code (file with line numbers, caret, selection and a diff since its last reply) and answers sentence by sentence.
Navigation commands like "highlight lines 3 to 6 and explain it" run locally with no model call. There are four help modes (Coach, Guided, Pair, Listen), ten one-click agents including an Optimize agent that returns an accept/reject diff, Copilot-style ghost text, and spend brakes: a daily budget, rate brake and live spend meter, because voice loops get expensive fast.
Hard parts
- Barge-in that cancels the model stream and tells the copilot what you did not hear
- Giving every turn precise code context: caret, selection and a diff since the last reply
- Spend controls for an always-listening loop
