90 Days to Success: What Integrating $1B in Acquisitions Taught Me

I’ve had the chance to integrate over a billion dollars in acquisitions throughout my career. Some were smooth. Some were messy. A few felt like trying to land a plane while rebuilding the runway. But every deal, no matter the size or sector, taught me the same core truth: the first 90 days post-close are where deals succeed or quietly start to rot.

It’s not about the LOI, the diligence, or even the purchase agreement. Those are just the preamble. The real work begins after the ink is dry.

1. The Numbers Matter, But the People Matter More

Most integration checklists start with systems, financial reporting, and compliance. All important. But what derails integrations isn’t usually a missed system sync—it’s misalignment, fear, and silence.

In founder-led or tightly held businesses, selling is emotional. So is handing over control. You might walk in as the new owner or operator with the best intentions and a rock-solid plan, but if you don’t earn trust fast, you’ll be solving the wrong problems while the real ones hide in plain sight.

I’ve learned to start with conversations, not controls. Ask the operators: What’s working? What’s broken? What do they think will change now? And then listen like their answers are the real diligence.

Because often, they are. Far too often, new owners disregard the institutional knowledge of the existing team, particularly in the back office. Leveraging the resources you already have and aligning incentives to create buy-in across the board will set the go-forward organization up for success.

2. Speed Creates Stability

There’s a myth that the safest way to integrate is slowly and carefully. But in practice, a slow integration usually leads to confusion, inconsistent messaging, and organizational drag.

That doesn't mean move fast and break things—it means be decisive.

I was brought into a client once where months had passed without any effort to consolidate back-office functions. That gap became a breeding ground for conflicting processes, duplicate vendors, and mistrust. When we did eventually force the functions together, there was significantly more resistance and pushback because of siloes which were created in that time gap.

So I now prioritize two things in week one:

1. Financial control and visibility

2. Clear roles and decision-making authority

That doesn't mean you're changing everything right away, but it does mean that everybody knows who's driving.

3. Don’t Lead with the Org Chart

One of the worst mistakes I see in early integration is treating it like a spreadsheet exercise: change reporting lines, cut duplicate roles, roll up the org. Technically correct. Culturally disastrous.

When you show up talking structure before strategy, people brace for impact. Productivity drops. Rumors fly. The very talent you paid to acquire starts looking elsewhere.

Instead, focus first on shared objectives: What does winning look like in this business now? What changes—if any—are truly urgent? From there, structure becomes a tool to support outcomes, not the starting point.

4. Accounting Is Your Early Warning System

If something’s off in the business, you’ll see it in the books first. That’s why one of my first moves post-close is a deep dive into accounting.

I don’t mean a superficial month-end review. I mean understanding how revenue is recognized, how costs are tracked, what manual workarounds are masking real gaps. This also ties back to the importance of historical knowledge, as cutting staff too quickly means that this critical information can be lost forever.

Clean, disciplined accounting early in the integration process is non-negotiable. It’s the difference between scaling on purpose and tripping in the dark.

5. Set the Tone—And Keep Repeating It

The first 90 days are where you set culture, even if you don’t mean to. If you’re reactive, vague, or hiding behind email, the company will mirror that. If you’re direct, transparent, and decisive, they’ll follow.

I’ve learned to over-communicate. Weekly updates. Open Q&As. Clear summaries of what’s changing and what’s not. And above all—a promise that when we say “we’re still figuring that out,” we mean it, and we’ll circle back.

People don’t need every answer in week one. But they do need to believe you’re leading with integrity and intention.

The Bottom Line

Integrating an acquisition isn’t just about systems or synergies. It’s about humans, habits, and hidden history. And in those first 90 days, you’re not just implementing change—you’re writing the first chapter of a new company story.

If you get it right, you set the tone for everything that follows. If you get it wrong, you’ll spend the next year cleaning up something that didn’t need to break in the first place.

$1B later, here’s what I know for sure: start fast, listen hard, and never underestimate the value of clarity.