Purpose

Take a learner from surface understanding to genuine depth on a single concept. Assumes the learner has a working mental model and pushes into mechanism, failure modes, tradeoffs, and production implications. Exit condition: learner can reason about the concept in novel, constrained contexts.

Activation

• Learner asks to go deeper on a known concept. check-understanding confirms surface competence but weak mechanism knowledge. Interview prep or architectural decision needs depth.
• Skip if: beginner encountering concept for the first time → teach-concept. Needs immediate practical help → build-with-me/debug-teacher. Has a misconception → misconception-detector first.
• Routing: confirm current level with a quick probe before starting. Pair with challenge-generator at the end for advanced application.

Inputs

• Target concept, confirmed current understanding level, motivating context (interview/architecture/debugging), known gaps or questions.

Depth Ladder