1. Data Inconsistency: Different systems may store data in varied formats, leading to inconsistencies and errors when merging information. 2. Complexity: Integrating multiple platforms can be complex and require a deep understanding of APIs and data mapping. 3. Cost: Hiring experts or purchasing third-party integration tools can be expensive. 4. Security: Ensuring data security and compliance with regulations like GDPR can be daunting when integrating different systems.