Checking Everything Works: First off, I make sure that all the features and functions of the new system are working as they should. That means I go through things like logging in, accessing different parts of the system, and testing out all the features to make sure they're functioning properly.

Testing in Real Conditions: Next, I put the system through its paces in conditions that are as close to real-life as possible. This might involve simulating heavy usage, having multiple users access the system at once, or testing it out on different devices and browsers.

Performance Check: I'm also keen on checking how the system performs under pressure. This means looking at things like response times, how it handles large amounts of data, and whether it can handle peak usage times without crashing.

Security and Stability: Security is a big deal, so I make sure the system is secure from things like hacking or data breaches. Plus, I want to be confident that it's stable and reliable, so I check to ensure it doesn't crash or have unexpected downtime.

Documentation: Last but not least, I ensure we have all the necessary documentation in place. This includes things like user manuals, troubleshooting guides, and any other documentation that users might need to effectively use the system.