I once had two tech leads who couldn’t stand each other. And it was becoming everyone’s problem.

Both were strong engineers leading their own sub-teams. The kind of people you want in positions of responsibility — smart, opinionated, invested in doing good work.

The problem was they’d stopped talking to each other and started talking about each other.

How It Started

There was no single triggering event. It wasn’t a stolen credit or a blown deadline or a technical disagreement that spiralled out of control. It was subtler than that — and more dangerous because of it.

Poor communication. A misread comment here, a skipped invitation there. The kind of small friction that most teams brush off but that, left unaddressed, compounds like technical debt on your worst codebase.

Over weeks, each of them had built a narrative about the other. And once you have a narrative, you start seeing everything through it. A neutral Slack message becomes passive-aggressive. Being left off a meeting invite becomes deliberate exclusion. Silence becomes judgment.

By the time it landed on my desk, it wasn’t private anymore. Their teams could feel it. People were picking sides. Collaboration between the two groups had basically stopped. Technical decisions that required both leads were getting delayed or made unilaterally.

As the team leader, I couldn’t let this continue.

The Conversations

I set up one-on-one meetings with each of them. Separately. No agenda. Just a direct opening:

“I know there’s a conflict between you and [the other person]. I’d like to hear your side.”

And then I listened.

The first lead spoke for about twenty minutes. Passionate, frustrated, hurt. The grievances poured out:

“He talks behind my back.”
“He doesn’t respect my work.”
“He questions my decisions to other people instead of coming to me.”
“I feel like he’s constantly judging everything my team does.”

I took notes. I asked clarifying questions. I didn’t defend or attack anyone.

Then I had the same conversation with the second lead. Same opening. Same listening.

And he said the exact same things. I mean the exact same things.

Not similar things. The same things. Almost word for word.

“He talks behind my back.”
“He doesn’t respect my work.”
“He questions my decisions to other people instead of coming to me.”
“I feel like he’s constantly judging everything my team does.”

I sat there staring at my notes thinking: these two people are mirror images of each other, and neither of them knows it.

The Mirror

Armed with this, I went back to each of them. Same one-on-one setting. Same direct approach.

I told each of them two things.

First, the accountability piece: “You hold an important position on this team. This conflict is visible to everyone. It’s affecting how your teams work together. We need to find a way to stop this.”

Both nodded. They knew. They weren’t oblivious — they just didn’t know how to fix it.

Then I told them what I’d found.

“I had the same conversation with [the other person]. And he told me the exact same things you just told me. He feels attacked by you. He thinks you don’t respect his work. He believes you’re talking behind his back. He’s hurting the same way you are.”

The reaction was identical both times. A pause. Wide eyes. And then:

“Really? He thinks that about me?”

That single moment — the realisation that the person you think is your adversary feels exactly the same way about you — removes the aggression instantly. You can’t keep attacking someone when you realise they’re not the villain you imagined. They’re just another person feeling the same hurt you are.

What Happened Next

They didn’t become best friends overnight. They were different people with different styles, and that’s fine. But the hostility evaporated.

They started having regular one-on-ones. They began collaborating on technical decisions that affected both teams. When there was a disagreement, they brought it to each other directly instead of letting it fester.

The change was visible to everyone. Their teams noticed. The invisible wall between the two groups came down. Decisions started flowing again.

All from two conversations and one observation.

Why This Worked

This particular conflict was driven by imagined intent, not actual wrongdoing. And in my experience, that’s a common pattern — though certainly not the only one.

When communication breaks down, people fill the gaps with the worst possible interpretation. The gap between “he didn’t reply to my message for three hours” and “he’s deliberately ignoring me” gets filled by imagination. And imagination, fuelled by existing friction, always goes dark.

When that’s what’s happening — when the conflict is built on assumptions rather than real wrongdoing — you don’t need a formal mediation process or an HR intervention or a team-building offsite with trust falls. (Please, never trust falls.)

You just hold up a mirror. “The person you think is attacking you? They feel exactly the same about you.”

This won’t solve every conflict. Sometimes one person really is the problem. Sometimes people genuinely have incompatible working styles and need to be separated. But when the root cause is broken communication and imagined intent, concrete empathy cuts through it faster than anything else I’ve tried.

What I’d Do Differently

If I could go back, I’d have acted sooner. By the time the conflict landed on my desk it had been festering for weeks, maybe longer. The narratives were deep. I got lucky that the mirror was so clean — if I’d waited another month, the damage to the teams might have been harder to undo.

As a fractional CTO I’ve dealt with variations of this since. The pattern I follow now:

Listen separately first. Never put two people in conflict in the same room as your first move. People are more honest — and more vulnerable — one-on-one. You need the unfiltered version from each side.

Look for the mirror. Check if they’re saying the same things about each other. It’s not always there, but when it is, you have a powerful key.

Be direct. This is the part most managers get wrong. Don’t hint. Don’t “facilitate a conversation.” Tell each person, plainly, what the other person feels. The shock of recognition does the work — but only if you deliver it straight.

And don’t take sides. The moment you align with one person, you lose the ability to be the honest broker. That’s the whole game.

Most engineering managers get zero training in this stuff. We promote the best engineer to lead the team and then act surprised when they don’t know how to handle two adults who won’t talk to each other. But this is half the job. Architecture and code matter, but they don’t matter much if the people building them can’t work together.

If your team has friction that’s slowing everything down, I might be able to help. This is a big part of what I do as a fractional CTO.

The Mirror That Ended a Team War