Name three most challenging areas while thinking of migrating applications to cloud? and WHY?

Based on my experience, the following are the3 areas of concern:

1, Security: Since you are handing over the custody of your data to an external entity you need to make sure they do meet the security and compliance requirement of your industry otherwise you might end up in a big mess.

2. Vendor Lock In: Once you move to a cloud service provider, you might be constrained by the product being offered. If they are open platform who support all the different typpe of solutions.

3. Performance: Application performance might be an issue as you would be dependent on the cloud service provider's infrastructure. An application with high bandwidth requirement might not be suitable.