Software integration refers to the process of connecting software applications with one another, which can include connecting internal teams' applications or connecting a product with third-party applications used by clients. To successfully build and maintain software integrations, several best practices should be implemented, including prioritizing integrations based on specific key performance indicators, establishing error-handling processes for edge cases, and tasking an engineer with overseeing documentation to ensure it is thorough and up-to-date. Additionally, security should be kept top of mind by implementing proactive measures such as encrypting data and using secure authentication methods. Adopting a unified API solution can also help meet customer demand for integrations at scale, and platforms like Merge offer unified APIs and integration maintenance support to take the load off engineers. By following these best practices and leveraging the right tools, organizations can build, maintain, and manage product integrations effectively.