How to check a lawyer's background?

We have been looking around for a potential immigration solicitor/barrister, and for some lawyers we might be interested in, we could not find his or her backgrounds and if he or she is a legit one.

Is there any website for verifying this type of information?

Thank you.

Don’t trust anyone until you verify them through home office website which is as

https://www.gov.uk/find-an-immigration-adviser

Thanks.
I actually checked the gov.com before, and I'm wondering if there're some other online databases to use.
Also, the 'find an adviser' 'function on gov.com has been down for a while too.