Mentoring juniors & conducting interviews
Mentoring: pair on real PRs, run weekly 1:1s, set growth goals tied to outcomes, give specific feedback close to the moment, model good debugging by thinking aloud. Interviews: structured rubric, calibrate across the panel, focus on signal not trivia, write detailed notes, separate observation from judgment, take a debrief seriously.
Mentoring and interviewing are skills senior engineers grow into. They're judged less on output and more on leverage.
Mentoring
What works
- Pair on real PRs, not abstract exercises. Reviewing their code while they explain is high-bandwidth.
- Weekly 1:1s — short, focused. Ask about blockers, growth goals, what's confusing.
- Tie goals to outcomes, not activities. "Ship the migration" not "learn React."
- Specific, timely feedback — at the PR, in the moment, not saved for review season.
- Think aloud while debugging. Juniors learn the meta-skill of how a senior approaches an unfamiliar problem, not just the answer.
- Sponsorship, not just mentorship — advocate for them when they're not in the room (promo committees, project assignments).
What doesn't
- Solving their problem for them every time. They don't grow.
- Vague feedback ("you need to ramp up").
- Treating juniors as ticket factories.
- Saving feedback for performance review.
Interviews
Structured rubric
Define the signals you want (problem decomposition, code quality, communication, edge cases, debugging) and what each looks like at each level. Score per signal, not vibes.
Calibrate
Run multiple interviewers on the same candidate. Compare notes before debrief. The point of a panel is independent signals — don't groupthink before the debrief.
Focus on signal
- Open-ended over trivia. "Implement debounce" beats "what does Object.create do." Most jobs don't quiz you on built-ins.
- Real-shaped problems. Build a small feature, not invert a tree.
- Talk it through. How they reason matters more than whether they finish.
Notes
Write detailed notes during, not after — observations and quotes, not conclusions. "Said: 'I'd use useMemo to avoid recomputing'" is more useful than "good React knowledge."
Separate observation from judgment
In notes: Observation: X. Judgment: Y. Bias correction is easier when they're separated.
Debrief
A real debrief, not a thumbs up/down. Each interviewer reads notes; discuss disagreements; remember the rubric. Don't reveal scores until everyone has shared — anchoring is real.
Adjust for nerves
Some candidates struggle in the first 5 minutes. Reset the question. Don't penalize panic; penalize lack of progress over the whole interview.
Hiring bar
Hire only for net positive. If someone is "neutral," pass — they cost more than they add at scale. Avoid optimizing for "no false negatives" — most companies should be optimizing for "no false positives."
Inclusive practices
- Same rubric for everyone.
- Don't ask "trick" questions; they correlate with prep access, not ability.
- Take-home + onsite hybrid for candidates who don't perform under pressure.
- Diverse panels.
Interview framing
"For mentoring: pair on real PRs, weekly 1:1s, specific timely feedback, think aloud during debugging, sponsor as well as mentor. For interviewing: structured rubric per signal, calibrate across the panel, focus on real-shaped problems not trivia, take detailed observation-based notes, debrief with rubric and without anchoring. Hire for net positive, not no-false-negative. And separate sponsorship from mentorship — advocate for people when they're not in the room."
Follow-up questions
- •How do you give feedback to someone resisting it?
- •What's the difference between a mentor and a sponsor?
- •How would you fix a broken interview loop?
Common mistakes
- •Vague feedback.
- •Doing the work for them.
- •Anchoring before debrief.
- •Quizzing trivia in interviews.
Performance considerations
- •Mentoring's ROI is multiplicative — a strong mentor lifts 5 engineers' output. Bad interviews cost in wrong hires and missed great candidates.
Edge cases
- •Mentoring someone outside your team.
- •Cross-cultural communication differences.
- •Underperformers — separate growth conversation from PIP.
Real-world examples
- •Lara Hogan's resilient management writings, Will Larson's Staff Engineer book, Camille Fournier's Manager's Path.