What matters when mentoring Junior Engineers

Over the past few years, I’ve given a talk about mentoring junior engineers at several conferences. What surprised me most was what happened afterwards: people kept coming up to share their own stories.

Someone would say, “Oh wow, that happened to me exactly like that.” Sometimes it was even: “This is the reason why I left the industry.” Others told me, “I will definitely try this out when working with my juniors.”

These conversations made me realize something important: mentoring rarely fails because people don’t care. It fails because we underestimate how much the small things matter. And in tech, mentoring rarely happens in formal programs anyway - it happens in everyday collaboration: during a pull request review, while debugging together, or when someone nervously asks their first “stupid” question. These moments often shape how people experience their first years in the industry — and whether they want to stay.

My own perspective comes from both sides of the mentoring relationship. I started my career in tech relatively late. So after being a senior mentoring juniors in my field for many years, I found myself being a junior again - mentored by experienced engineers. Seeing mentoring from both sides made one thing very clear to me: interactions we often consider routine can have a huge impact on someone who is just starting out. That’s why I thought it might be worth sharing some of these ideas here as well.

The first thing to understand: Juniors are overwhelmed

When someone joins the industry as a junior engineer, they are stepping into a world that is far more complex than it looks from the outside.

It’s not just the code. It’s:

unfamiliar tooling
complex systems
team dynamics
implicit expectations
and a whole vocabulary nobody explained.

Even asking questions can feel risky. So many juniors constantly worry: Is this a stupid question? Should I already know this? Am I slowing everyone down? A good mentor understands this invisible pressure - and works actively to lower it. And sometimes the most important sentence you can say is simply: “That’s a good question.”

Mentoring is not about being the smartest person in the room

One of the biggest misconceptions about mentoring is that mentors need to know everything. You don’t.

In fact, the best mentors often don’t immediately give answers at all. Instead they ask questions like: What have you tried so far? What do you think might be happening? Where would you start debugging this? This helps juniors build something far more valuable than quick solutions: confidence in their own thinking process. And that’s the real goal. Because sooner or later every engineer will end up staring at a problem nobody else understands either.

Small moments matter

Mentoring rarely happens in big dramatic teaching moments, but in small interactions:

reviewing a pull request together
debugging something side by side
explaining why a design decision was made
encouraging someone to present their work

Those moments might feel routine to you. For a junior engineer, they can be nerve-wracking. As a mentor, these are great opportunities to slow down a little. Explain your thinking, ask what they would try next, or simply acknowledge when something was done well. Small interactions like these often have a bigger impact than long formal teaching sessions.

Feedback is a skill

Giving feedback is one of the most powerful tools mentors have - and also one of the easiest to get wrong. Helpful feedback is:

specific
constructive
focused on growth

Instead of saying: “This code isn’t very good.”

try: “This part works well. For this section, you might consider splitting the function so it’s easier to test.”

The goal isn’t just to correct mistakes. It’s to teach how to improve.

Pro Tip: Instead of suggesting to split the function - ask the junior if they have any ideas for improving further.

Psychological safety beats perfection

Junior engineers learn fastest in environments where they feel safe to experiment. That means:

mistakes are expected
questions are welcome
curiosity is encouraged

If someone is afraid of looking stupid, they will stop asking questions. And when questions stop, learning stops too. Good mentoring hence builds a culture where people feel comfortable saying: “I don’t understand this yet.”

Mentoring is also about trust

One of the hardest things for mentors is learning when to step back. If you constantly jump in and fix everything yourself, juniors never get the chance to solve problems independently. Instead, try this:

give hints instead of solutions
let them explore possible fixes
support them if they get stuck

I get it - watching someone struggle a little can feel uncomfortable. But those moments are often exactly where the real learning happens.

The best mentors remember what it felt like

It’s easy to forget how confusing the beginning of a tech career can be. Most senior engineers eventually reach a point where things feel natural:

reading code
navigating large systems
debugging complex problems

But for juniors, none of that is obvious yet.

Good mentors remember what it felt like to be new - and treat questions with patience instead of frustration. Because every experienced engineer today once asked those same questions.

Why this matters

Mentoring isn’t just about helping one person. It shapes teams, cultures, and careers. A supportive mentor can:

help someone stay in the industry
give them confidence to speak up
encourage them to try new challenges
and sometimes change how they see themselves as engineers.

Those effects can last far longer than any single project.

Summing up

The best mentors rarely do anything spectacular - they do small things consistently:

listening
encouraging
explaining
asking good questions
and making learning feel safe.

And those small things often turn out to be the ones people remember years later.

So if you’re mentoring someone right now - or thinking about starting - remember: You don’t need to have all the answers. Sometimes the most powerful thing you can do is simply say: “Let’s figure this out together.”

If you’re curious about some of the real mentoring situations behind these ideas, you can watch the recording of the talk where I share a few examples.