The First 90 Days as a New Head of Growth

A new Head of Growth joining a B2B company at growth stage has roughly 90 days before their observation period ends and active execution is expected. What they do in that window largely determines whether they're building from a clear foundation or from assumptions that will turn out wrong six months later. Most new Heads of Growth spend the 90 days on a mix of meeting people, absorbing context, and launching initial tactical work. This feels productive and usually isn't, it produces activity but not the structural understanding that makes subsequent work compound.

This article is written for someone who's just taken a Head of Growth role, or who's about to. The structure of 90 days that actually produces compound outcomes rather than activity. What to investigate, what to resist doing, and how to set up the first real initiative so it lands on solid ground.

Why Most First 90 Days Produce Activity Without Compounding

Three specific patterns that make new Heads of Growth underperform in their first quarter.

Pressure to show fast wins. The leadership team (and often the hire themselves) wants to see movement within weeks. This produces tactical work, launching a campaign, refreshing landing pages, restructuring the team, that demonstrates activity without addressing the underlying issues. Tactical wins at month 2 often mask foundational problems that emerge at month 8.

Inherited assumptions treated as given. The existing team has a way of describing the business, who the ICP is, what's working, what the constraints are. New leaders tend to absorb these descriptions as fact rather than testing them. When the descriptions turn out to be incomplete or wrong (which they usually partly are), the strategies built on them fail.

Team management displaces strategic work. The new Head of Growth inherits direct reports who each have immediate needs, review priorities, approve budgets, give feedback on in-flight work. This management work fills the calendar and squeezes out the investigation the role actually requires in the first quarter.

The pattern that works inverts this. Defer tactical wins, test inherited assumptions rigorously, and protect time for structural understanding even at the cost of feeling less productive in weeks 2-6.

What The First 90 Days Should Actually Produce

Three specific outputs by day 90 that indicate the first quarter was spent well.

An honest diagnostic of the current growth operation. Where the funnel is actually broken (not where the team thinks it is). Which channels are producing pipeline versus producing noise. Whether the ICP definition matches who the business closes. Whether the positioning is testable or generic. Whether the team structure matches the work that needs doing. This diagnostic should differ meaningfully from the description the CEO gave during interviews.

A named 90-day plan for the next quarter with specific commitments. Not a broad strategy document, a specific plan that names 3-5 initiatives the team will execute in the coming quarter, what each is meant to produce, and what the team will stop doing to make space. The plan should be defensible with the evidence from the diagnostic.

A credibility foundation with the CEO and leadership team. Not based on fast wins, but based on having produced a diagnostic that leadership recognises as sharper than what they had before. This credibility is what lets the subsequent work get space and support rather than second-guessing and interference.

The Structure Of The 90 Days

Three 30-day blocks, each with a specific primary focus.

Days 1-30: Observation And Data

The first month is spent deliberately not making commitments. The goal is absorbing the business accurately rather than pattern-matching to previous experience.

Primary activities: structured conversations with 20-25 people across leadership, growth, sales, customer success and product, plus 5-8 recent customer research calls (not sales calls), 3-5 churned customers if accessible, and a few prospects in active deals. Each conversation follows a similar structure so you can compare across them.

Quiet data investigation: pull the actual numbers for the last 12 months. Pipeline by source, closed-won by segment, conversion rates at each stage, retention cohorts, CAC by channel. Compare what the data shows to what people describe. The gaps are informative.

CRM and tooling inspection: get admin access. Look at data hygiene, field population rates, workflow configurations. Understand what the infrastructure can produce versus what it currently produces.

Existing content, collateral, and marketing audit: read what's been published. Review the sales deck. Look at the website as a prospect would. Note the gaps between what's there and what the diagnostic will likely show is needed.

What not to do in the first 30 days: launch anything new, make any personnel decisions, commit to targets, or announce a strategy. These all come later. The first 30 days are for seeing the business clearly.

Days 31-60: Diagnosis And Hypothesis

The second month converts observation into a working diagnosis. What's actually the constraint? Where is the business losing the most leverage? What would need to change for growth to compound rather than fragment?

Primary activities: running the diagnostic frameworks you'd run for a client. The growth readiness assessment. The full-funnel audit. Whatever structured diagnostic you trust. The output isn't a report for leadership, it's your own view, written down, that you can challenge and refine.

Testing assumptions with data: the team said LinkedIn produces pipeline. Does it actually? The CEO thinks the ICP is Segment A. What does the closed-won data show? Testing specific claims against data surfaces which parts of the inherited narrative hold up and which don't.

Drafting a hypothesis tree following the growth hypothesis tree pattern. What does the business's plan actually depend on being true? Which of those are confirmed, weakly evidenced, or assumed? The tree at end of month 2 will be rough; refined version comes at month 3.

Socialising early insights with the CEO: ongoing conversations where you share what you're seeing and test your interpretations. This prevents the month-3 presentation from being a surprise and lets the CEO adjust early if your diagnostic is heading somewhere they weren't expecting.

What not to do in days 31-60: commit to a plan, restructure the team, or launch major initiatives. You still don't know enough to make these calls well.

Days 61-90: Plan And Commit

The third month produces the plan for the coming quarter and begins committed work.

Convert the diagnostic into a 90-day plan: three to five named initiatives that, if executed, address the most load-bearing constraints the diagnostic surfaced. Each one specific enough that someone could execute it, with clear success criteria.

Communicate the diagnostic and plan to leadership and team in a formal presentation. This is the first moment you're meaningfully visible as the Head of Growth to the broader organisation. The quality of this presentation significantly shapes how the subsequent quarter goes.

Team and structure adjustments if required: by month 3, if specific roles, hires, or agency relationships need to change, you've earned the credibility to make the calls. Making them earlier usually lands badly because you don't have the evidence to defend the decisions.

Launch the first one or two initiatives, not all five at once. The highest-leverage and cleanest to execute. This produces early momentum for the plan without stretching the team across too many simultaneous changes.

What To Resist In The First 90 Days

Five specific urges that will arrive and should be resisted: a big team off-site in the first month, committing to pipeline or revenue targets in the first month, major spend changes in the first month, personnel decisions in the first month, and external agency changes in the first month. The honest answer to "what are your targets" in week two is "I'll have targets at the 90-day mark after I've completed the diagnostic." Most CEOs respect this when framed confidently.

Where This Fits In The Broader Role

The first 90 days set the foundation for the next 18 months. A well-executed first quarter produces a diagnostic that remains valuable, a team that trusts the new leader's judgement, and a strategic direction that's defensible. A poorly-executed first quarter produces the opposite on all three, and those deficits are hard to recover from.

If you're about to start a Head of Growth role and want to pressure-test your 90-day plan, or you're partway through and uncertain whether you're on the right track, get in touch for a strategy call. We've walked this path with enough operators that pattern recognition helps.