Mergers and acquisitions are often driven by strategic growth, market expansion or operational efficiency. But one area that is frequently underestimated during the deal process is technology and that oversight can significantly change the complexity of the integration once the deal closes.
Having gone through several acquisitions, I have seen a consistent pattern emerge. While every integration brings a different level of complexity, many of the underlying technology challenges tend to repeat themselves.
In my experience, real work begins when you start to look under the hood. That is when technical debt, undocumented integrations, inconsistent data models, aging infrastructure and security gaps start to surface. The real surprises are often the things you do not initially see: Dependencies and risks that only appear once teams dig deeper.
Technology rarely determines whether a deal gets signed. But it often determines how difficult the integration becomes afterward, and, in some cases, the underlying technology complexity can make what initially looked like a valuable deal far less attractive than expected.
That is why CIOs and technology leaders must be involved early in the due diligence process. When technology diligence is treated as an afterthought, organizations risk inheriting operational complexity, cybersecurity exposure and integration timelines that are far longer than anticipated.
Bring IT into due diligence earlier
In many acquisitions, technology due diligence happens late in the process. By that point, leadership may already have expectations about the deal’s value, the integration timeline and the synergies the acquisition will deliver.
That is when surprises can emerge.
Over time, I have learned that technology diligence must go far beyond a simple inventory of systems. Understanding how those systems support the business is just as important. How data moves between applications, how reporting is generated and how security controls are implemented often matter more than the systems themselves.
In one integration effort, I experienced the process from the other side when the company I was working for was being acquired. As the acquiring organization began its technology diligence, it became clear that several systems were running versions that were no longer supported or were out of compliance with current standards. While those systems continued to function for daily operations, they introduced real risks for the acquiring company including security exposure, limited ability to apply patches and potential compliance concerns once integrated into a larger enterprise environment.
That experience reinforced how important it is for acquiring organizations to evaluate lifecycle status, supportability and compliance readiness during diligence rather than simply confirming that systems are operational.
Through several acquisitions, I have also found it useful to maintain a technology due diligence checklist that evolves after each integration. Every deal reveals new questions that should be asked earlier the next time. Over time, that checklist becomes one of the most valuable tools a CIO can bring to the deal process.
Industry research reinforces this point. In my experienc,e integrations go more smoothly when leaders treat diligence and integration planning as a discipline rather than a scramble. McKinsey’s research on merger integration highlights the importance of structured planning and governance early in the process (McKinsey’s “Perspectives on merger integration”).
Expect hidden complexity beneath the surface
Even when a target company appears technologically mature, teams often uncover hidden complexity once integration work begins.
One of the most common challenges is undocumented system integrations. Many organizations operate with scripts, scheduled exports or small applications built years earlier that quietly connect systems together. These dependencies may not appear in architecture diagrams, but often support critical business processes. In some environments, the knowledge behind these integrations lives with one or two individuals, creating key man risk if that knowledge is not documented before integration begins.
Data is another frequent challenge.
Two companies may run similar applications, yet their underlying data structures can be completely different. Product hierarchies, customer definitions, vendor records and financial reporting structures often evolve independently within each organization, which makes data integration far more complex than system integration. KPMG’s research on complex deal integration highlights how misaligned data models frequently become one of the largest integration challenges organizations face (KPMG, Mastering Complex Deals and Integration, 2024).
Technical debt is another reality that often surfaces during integration. Systems that appear functional during diligence may be built on legacy platforms that are difficult to scale or integrate with modern architecture. In other cases, organizations discover overlapping applications that perform similar functions or vendor contracts that no longer align with the combined technology strategy. These situations add unnecessary complexity and increase operational overhead across the enterprise.
Security is another area that requires careful attention and this is rarely about assigning blame. Smaller or growing organizations often operate with limited security resources, and their environments may evolve quickly over time. As a result, integration teams may discover outdated security controls, unknown access points or configurations that would not meet the acquiring company’s standards.
Given the constant news around cyber breaches and backdoor attacks, overlooking these risks can create real liability for the acquiring organization. Once an acquisition becomes public, the newly acquired company can quickly become a more attractive target for attackers, particularly if systems have not yet been integrated into the acquiring company’s security environment. Deloitte’s research on cyber risk in M&A transactions highlights the importance of evaluating these risks during diligence (Deloitte on cyber risk in M&A transactions).
Cybersecurity insurance can also become a factor. Policies often require organizations to meet certain security standards and inherited vulnerabilities or aging infrastructure can complicate compliance if they are not addressed early in the integration. In some environments where governance has been limited, technology adoption can resemble the wild west with individuals deploying tools or systems outside of formal oversight, which can unintentionally introduce security gaps or backdoor access points.
For that reason, it is important during diligence to review security policies, understand the organizational structure responsible for technology oversight and examine licensing and system ownership. These steps help identify potential exposure and ensure the acquired environment can align with the acquiring organization’s security standards and cybersecurity insurance requirements.
Another pattern I have seen across acquisitions is that the type of complexity often depends on the size of the organization being acquired.
With smaller companies, the challenge is often that their technology environments are heavily reliant on managed service providers. Core systems may be hosted within an MSP’s infrastructure, and the acquiring organization quickly finds itself navigating contract terms, service agreements and transition timelines. In some cases, systems are tightly integrated into the MSP’s environment, which can make extracting or migrating them more complicated than expected.
Larger organizations present a different kind of complexity. Their environments tend to be more mature but also far more layered. Multiple systems, specialized platforms and deeper technical teams create questions about where capabilities overlap and whether the right skills exist within the combined organization.
Integration success depends on people, process and realistic timelines
Technology often receives the most attention during acquisitions, but successful integrations depend just as much on people and process.
Business leaders understandably want to capture the benefits of an acquisition quickly. But technology integrations rarely follow identical timelines. Each environment introduces its own architecture, technical debt and operational dependencies.
One lesson I have learned is that organizations improve their integration speed over time by building integration muscle. With each acquisition, teams refine their playbooks, improve governance and develop a clearer understanding of how long certain types of work actually take.
Realistic expectations make a difference here. When integration timelines are grounded in experience, both technology teams and business leaders can plan more effectively.
Just as important is ensuring technology teams are partnered with the right business leaders during integration. In several acquisitions I have been involved in, having a representative from the business, often from a business process organization, proved critical in helping bridge the gap between technology and operations.
These leaders help ensure that systems are not simply connected but that the underlying business processes are aligned.
Employees in newly acquired organizations often face uncertainty about their roles, their systems and their future within the combined company. Without clear communication and leadership, that uncertainty can slow adoption and complicate knowledge transfer.
Mergers and acquisitions will always introduce complexity. But when CIOs are involved early in the diligence process, prepared to uncover hidden technology dependencies, integrations become far more manageable.
Technology may not drive the acquisition decision itself. But in many cases, it determines whether the value of the deal is ultimately realized.
As AI becomes more embedded in enterprise operations, it introduces a new layer of diligence and integration considerations. CIOs will increasingly need to evaluate not only systems and infrastructure during diligence but also how AI is being used, governed and secured within the target environment.
Looking under the hood will only become more important as technology environments continue to evolve. The deal may be negotiated in the boardroom, but its success is ultimately decided in the integration.
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