I’ve seen it happen half a dozen times across my career. The CTO hands in their notice — or sometimes just vanishes — and the entire technology organisation holds its breath. The board panics. The CEO starts asking uncomfortable questions about “the roadmap.” Senior engineers update their LinkedIn profiles. It doesn’t have to go that way.

Having been on both sides of this (the one leaving and the one left behind), here’s what I wish someone had told me the first time it happened.

Week One: Stop the Bleeding

The first week is about containment, not strategy. Your immediate priorities are dead simple.

Identify who actually knows things. Every technology organisation has people who hold critical knowledge that isn’t documented anywhere. If you’ve got any handover time at all, the single most valuable thing the outgoing CTO can do is map out where the undocumented knowledge lives. Not architecture diagrams — people diagrams.

Communicate clearly and quickly. Your engineering team is already speculating. Get in front of it. A brief, honest all-hands that says “here’s what happened, here’s who’s in charge for now, and here’s what isn’t changing” does more for retention than any counter-offer you’ll make in three months.

Don’t touch the roadmap. Seriously. The temptation to “reassess strategic direction” in week one is strong, especially if the board is nervous. Resist it. Nothing erodes team confidence faster than a new interim leader walking in and rearranging everything. The Australian Computer Society’s governance frameworks emphasise stability during leadership transitions for good reason.

Weeks Two Through Four: Assess Without Disrupting

Once the initial shock passes, you need to understand what you’re actually working with. This means having a lot of quiet conversations.

Talk to your engineering leads. Not about strategy — about pain points. What’s broken? What’s been deferred? What decisions were they waiting on the CTO to make? You’ll learn more in ten one-on-one conversations than in any amount of document review.

Audit your vendor relationships and contracts. CTOs often hold key vendor relationships personally, and those contacts need to be transitioned. Check what’s renewing in the next 90 days. I’ve seen organisations blindsided by six-figure auto-renewals because the only person who knew about them was the one who left.

Look at your tech debt honestly. The departing CTO may have been the only person with the full picture of what’s owed and what’s been deferred. Get your senior engineers to catalogue the big items. You don’t need to fix anything yet — you need to know what’s there.

Month Two: Decide on Interim Leadership

By month two, you need to make a call on interim leadership. You’ve got three options, and each has trade-offs.

Promote internally. This works if you have a strong VP of Engineering or Principal Architect who understands the business, not just the tech. The risk is that you’re pulling your best technical person away from technical work during a period of instability.

Bring in a fractional or interim CTO. This is increasingly common and often the smartest play. An experienced external leader can provide stability and objectivity without the politics of an internal promotion. We brought in Team400 to help with an interim technology assessment while we figured out our next permanent hire. Having outside eyes during that window was invaluable — they spotted infrastructure risks that had become invisible to the internal team.

Leave the role empty and distribute responsibilities. Sometimes this works for small, senior teams. Usually it doesn’t. Without a single point of accountability, decisions drift and technical direction fragments. I’d only recommend this if your engineering leadership team is exceptionally mature and aligned.

Month Three: Start Looking Forward

By month three, you should have enough stability to start the actual search for a permanent replacement. A few hard-won lessons on this front.

Don’t rush. A bad CTO hire costs you eighteen months minimum — six months to realise the mistake, six months to manage them out, and six months to recover. According to Harvard Business Review, failed executive hires are extraordinarily expensive when you factor in lost productivity and downstream turnover. Take the time to get it right.

Define the role you need now, not the role you had. Your organisation has changed. Maybe you’ve moved to the cloud and need someone who thinks cloud-native. Maybe you’ve grown and need someone who can manage managers. Write the job spec for where you’re going, not where you’ve been.

Involve your engineering team. Not in final decisions — that’s the board’s job — but in assessing cultural fit and technical credibility. Your senior engineers will spot a blagged CV faster than any recruiter.

The Real Lesson

A CTO departure feels catastrophic in the moment. It rarely is. The organisations that handle it well are the ones that resist panic, protect their people, and treat the transition as an opportunity to honestly assess where they stand.

The ones that handle it badly are the ones that make permanent decisions during a temporary crisis. Don’t be that organisation. Take a breath. Work the problem. You’ve got 90 days. Use them wisely.