Mentorship: junior pairing
This course covers mentoring a junior developer in one specific Rails codebase, written almost entirely by one author and documented in a 659-line MEMORY.md. It starts with the conventions a newcomer cannot derive from reading the code, then compares four pairing modes. It covers choosing how to answer a question, writing labelled review comments with reasons, and deciding what belongs in the shared document. It ends with choosing tasks for growth, giving actionable feedback, and a plan for a newcomer's first month.
What you'll learn
- ✓The five conventions in this codebase that reading the code cannot reveal
- ✓Four pairing modes and when each one fits
- ✓Choosing a rung on the question ladder, with a timebox for asking for help
- ✓Labelled review comments that give the reason behind each rule
- ✓Deciding what to write down and keeping MEMORY.md accurate
- ✓Stretch tasks with support and situation, behavior, impact feedback
What this codebase asks of a newcomer
Mentoring is specific to a codebase before it is anything else, so start with this one. What does someone joining have to know before they can write a line that would be merged?
Read the full lesson free →Curriculum
7 lessonsWhat this codebase asks of a newcomer
Why one author's consistent conventions are hard to join, the five rules the code cannot reveal, and good first tasks.
Pairing modes
Driver and navigator, ping-pong, strong-style and silent observation, with when to use each and common failure modes.
The question ladder
Four ways to respond to a question, how to choose between them, timeboxes, and when to interrupt.
Code review as mentorship
Labelling review comments, giving the reason for each rule, citing MEMORY.md, and habits that discourage a newcomer.
Answering once
What MEMORY.md does well, two places it drifted from the code, and which questions deserve to be written down.
Growth, not throughput
Pairing stretch with support, delegating outcomes with a pointer, situation-behavior-impact feedback, and four traps for mentors.
Putting it together: a first month
A week-by-week plan for a newcomer's first month, and a test for whether the mentoring worked.