An interim CISO can provide immediate leadership during transitions, incidents, or transformation programmes. We outline best practice for scoping, sourcing, and managing interim security leaders.
← Back to Insights
When your CISO leaves unexpectedly, or you've just experienced a security incident, or you're running a transformation programme, you don't have months to wait for a permanent hire. An interim CISO can give you immediate leadership, decision-making authority, and the experience to navigate the crisis or change. Done well, an interim engagement is not a band-aid—it's a strategic move that can stabilise your security posture while you build for the long term.
The right interim leader brings more than a title. They bring credibility with your board, the ability to operate effectively from day one, and the judgment to know what needs attention and what can wait.
Several scenarios call for interim CISO appointments. There's the straightforward gap: your permanent CISO departs and a replacement won't start for three months. A senior security incident demands immediate, credible leadership to manage the response, coordinate with regulators, and guide your organisation through recovery.
Transformation programmes—whether implementing a new security operating model, migrating to a cloud infrastructure, or building out a new SOC—often require specialist expertise for a defined period that a permanent hire can't justify. And sometimes a board needs experienced guidance before they can even define what the permanent CISO role should look like.
In each case, the interim serves a distinct purpose: unblocking decisions, providing credibility, and buying time to get the permanent hire right.
The difference between an effective interim and a wasted budget is clarity at the start. Be specific: what outcomes are you expecting? What decisions do they need to make? How long is the engagement—three months, six months, until a permanent hire is in place?
Define reporting lines and decision-making authority. An interim who is sidelined by layers of approval or treated as a contractor filling a seat will deliver neither impact nor credibility. They need genuine authority to make decisions within their remit and to drive change.
Equally important: make clear that they're building sustainable capability, not creating a dependency. The best interim engagements end with documented improvements, trained staff, and a clearer picture of what the permanent role requires. They should be leaving you stronger, not just quieter.
The interim CISO market is different from permanent recruitment. You're not looking for someone who fits your culture long-term or shows potential for development. You're looking for someone who can operate effectively on day one.
That requires proven leadership experience—ideally in your sector or similar operational environments. It requires the ability to deliver impact quickly and comfort with ambiguity. A CNI organisation recruiting an interim needs someone who understands the regulatory environment, the geopolitical context, and the operational pressures of critical infrastructure.
Specialist search firms maintain networks of vetted interim leaders who can be deployed at pace, often within two to four weeks. They've worked with these individuals before, they know their capability, and they can match you to someone who fits your specific challenge.
Once you've appointed an interim, give them space to operate. Weekly board updates, overly restrictive approval processes, or micromanagement will undermine their effectiveness. They're hired for their judgment—use it.
Maintain regular check-ins on progress against objectives. If you've scoped the engagement clearly, you'll both know what success looks like. And plan for succession: how will you transition from interim leadership back to permanent, or from one interim to another? Poor handovers can undo the work of the interim period.
The interim CISO market reflects a broader reality: the most experienced security leaders in CNI are in high demand and often unwilling to commit to permanent roles unless the context is exactly right. Interim engagements tap into a talent pool that traditional recruitment can't reach.
They also buy you time to hire properly. Rushing a permanent CISO hire because you're desperate for leadership is how organisations end up with the wrong person for three years. A three-month interim engagement might cost more per month, but it's cheaper than a bad permanent hire and the disruption that follows.
For organisations in critical national infrastructure—energy, transport, finance, defence—having access to experienced interim security leaders is a strategic asset. It's insurance against the unexpected and the means to run programmes that require specialised expertise for a defined period.
The demand for experienced CISOs in critical national infrastructure far outstrips supply. We examine what's driving the gap, how organisations can compete for scarce talent, and why traditional hiring approaches are failing.
AI spending on network automation will reach $20 billion by 2028. For CNI operators, deploying AI effectively requires professionals who understand both the technology and the operational context of critical infrastructure.
Trusted by security leaders at
"I can't recommend Gyles and the team at Foundations enough. We struggled to find a suitable candidate for 5 months, Foundations found 3 perfect candidates in 24 hours."
Manager of EMEA & APAC Network Engineering, Equinix
