Mentoring 1:1s: how to grow engineers effectively

What mentoring actually is

Mentoring is a long-term relationship where one person (the mentor) helps another (the mentee) develop their skills, perspective, and career. It’s distinct from:

• Managing — giving direction, evaluating performance, making hiring decisions
• Coaching — short-term, focused on a specific skill or behaviour
• Teaching — transferring specific knowledge

A good mentor asks questions more than they give answers. The mentee’s growth is the goal, not the mentor’s expertise being demonstrated.

The 1:1 meeting

The 1:1 is the most common mentoring format. It looks like a meeting but it’s actually a development tool. Good 1:1s:

• Happen on a fixed cadence (weekly or biweekly, never less than monthly)
• Are owned by the mentee (they bring the agenda)
• Are 30-60 minutes
• Have no other attendees (1:1, not 1:many)
• Have notes (the mentee writes them down)

The mentee’s agenda

A good mentee brings an agenda like:

1:1 with Alex — 2026-08-08

Topics:
- Career goal for Q3: get comfortable with Ceph tuning
- Stuck on: choosing between bluestore tuning and OSD reweighting
- Tension: I'm not sure if my architecture review feedback is landing
- Question: should I propose for promotion now or wait?
- Personal: my home lab is broken, debugging this weekend

This agenda is better than “what’s up”. The mentee is doing the work of thinking about their development; the mentor’s job is to support.

Question types that develop engineers

The mentor’s toolkit is questions. Some types:

Open-ended

• “What did you learn from that incident?”
• “What would you do differently next time?”
• “What’s blocking your progress?”

Probing

• “Tell me more about why you chose that approach”
• “What did you rule out, and how?”
• “What’s the strongest argument against your plan?”

Reframing

• “How would your manager see this?”
• “If you were the customer, would this matter?”
• “What would you tell a junior in your position?”

Forward-looking

• “Where do you want to be in 12 months?”
• “What’s the next skill you need to develop?”
• “What would a stretch project look like for you?”

Avoid:

• Closed yes/no questions
• Leading questions (“Don’t you think X is better?”)
• Multiple questions at once

Giving feedback

Feedback is the most valuable thing a mentor gives. The SBI model (Situation, Behaviour, Impact) is a clean framework:

Situation: When and where Behaviour: What they did Impact: What effect it had

For example:

“In the architecture review on Tuesday (S), when you cut off Priya mid-sentence (B), the room got quiet and she didn’t bring up her concern later (I).”

Compare to:

“You were rude to Priya.”

The first is feedback; the second is a label. Labels trigger defensiveness; feedback invites reflection.

Receiving feedback gracefully

The other half of feedback is receiving it well. As a mentor, model the behaviour:

• Listen without interrupting
• Ask for clarification if needed
• Acknowledge the impact, not the intent
• Don’t make excuses
• Commit to a change

Building a growth plan

A growth plan is a written document that captures the mentee’s goals, current state, and actions. Structure:

# Growth plan: Alex

## Goal for next 12 months
Be a strong mid-level engineer; ready for promotion in 12-18 months.

## Strengths to build on
- Calm under pressure
- Strong technical writing
- Good collaborator

## Gaps to close
- Less comfortable with ambiguous projects
- Avoids giving feedback to peers
- Limited exposure to architecture-level decisions

## Development activities
- Lead one ambiguous project end-to-end (Q3)
- Practice giving feedback in 1:1s, with my coaching
- Shadow architecture reviews and write up notes

## How we measure progress
- Self-assessment against the level expectations
- Quality of feedback given (tracked in 1:1s)
- Outcome of the Q3 stretch project

## Resources
- Book: "The Staff Engineer's Path" by Tanya Reilly
- Internal: senior engineer shadow programme

This is a living document. Update it every 1-2 months.

Mentoring across experience levels

Different mentees need different approaches:

Career starters (0-2 years)

• Lots of teaching, lots of structure
• High-frequency 1:1s (weekly)
• Focus on fundamentals: technical communication, debugging discipline

Mid-career (3-8 years)

• More coaching than teaching
• Biweekly 1:1s
• Focus on independence: design judgement, navigating ambiguity

Senior (8+ years)

• Mostly peer mentoring, occasional questions
• Monthly or as-needed 1:1s
• Focus on leadership: influencing without authority, mentoring others

Common mentoring mistakes

“I’ll just tell them what to do”

This is teaching, not mentoring. Teaching has its place; mentoring develops the mentee’s own judgement.

“I’ll fix the problems they bring me”

If the mentee brings a problem every 1:1 and you solve it every time, you’re not developing them. Coach them to solve it themselves first.

“I’ll keep it private”

Confidentiality is critical but you should still calibrate with other mentors or managers. “Alex is growing fast” or “Alex seems stuck on feedback” is important context.

“We don’t need structure”

Without a cadence and a plan, 1:1s devolve into coffee chats. Structure is a kindness.

“I’ll mentor everyone”

Better to mentor deeply than widely. 2-4 mentees at a time, full attention.

When to end the mentoring relationship

Most mentoring relationships have a natural arc:

1. Intensive phase: weekly 1:1s, focused on a specific goal
2. Plateau phase: biweekly or monthly, mostly peer conversation
3. Transition: mentee is now independent; relationship shifts to peer/colleague

Don’t force a mentoring relationship to last forever. When the mentee has grown, acknowledge it: “You’ve outgrown me in some areas. Let’s keep meeting monthly for general discussion, but you don’t need weekly mentoring from me anymore.”

Key takeaways

• Mentoring is about the mentee’s growth, not your expertise
• The mentee owns the agenda
• Ask more than you tell
• Use SBI for feedback, model receiving feedback well
• Build a growth plan; update it quarterly
• End the relationship when the mentee has grown

Knowledge check