Don't just hand an integration plan to functional leaders post-close. Involve them early in the process as co-architects. Their input is crucial for validating financial models and strategic assumptions, ensuring realistic expectations and fostering ownership of the deal's success.

American investors often underestimate the need for a physical management presence in Italy. Successful integration requires local leaders who can liaise with suppliers, customers, and authorities. Attempting to manage an Italian acquisition remotely from the US or another European hub is a common point of failure.

To ensure Day 1 alignment and retain key talent, treat integration planning as a collaborative process. Share the developing integration plan with the target's leadership during due diligence. This allows them to validate assumptions, provide critical feedback, and feel like partners in building the future company, rather than having a plan imposed on them.

The most critical lesson from integrating 22 acquisitions wasn't about perfecting data migration. Instead, success was determined by spending significant time with acquired teams *before* migrating core systems. This human-centric approach ensures teams feel supported and bought into the new direction, which is more impactful than technical flawlessness.

To avoid a broken handoff, embed key business and integration experts into the core deal team from the start. These members view diligence through an integration lens, validating synergy assumptions and timelines in real-time. This prevents post-signing surprises and ensures the deal model is operationally achievable, creating a seamless transition from deal-making to execution.

During a merger, prioritize people over process. Technical integration is secondary to building trust between teams. Use simple, cultural activities like joint happy hours and "show-and-tells" about the tech stack to humanize the engineering effort and foster empathetic collaboration early on.

A process where the deal team hands off a signed transaction to a separate integration team is flawed. State Street integrates business and integration experts into the deal team from the start. This ensures diligence is informed by integration realities, timelines are realistic, and synergy assumptions in the deal model are achievable.

The key to post-acquisition integration isn't a perfect plan, but spending significant time on the ground with the acquired team. Leaders must earn the right to lead by demonstrating consistency and empathy over weeks and months, as initial promises are met with skepticism. A single presentation won't win anyone over.

The handoff from due diligence to integration is a critical failure point. M&A leads should personally walk functional leaders through diligence findings mid-process, well before close. This builds crucial buy-in and ensures resource commitment for post-close execution.