Web usability: select from very large data

On the project I joined, somewhere the user has to select a value (a person) from a very large set (average 1 000, can go up to 30 000). The current solution is to ask for at least 3 letters of the {firstName lastName} string, and then populate a dropdown with all the matching people so there is a lot less to scroll before finding the right person.

I find it quite painful to use, are there other ways to handle selection from large data?