How do you shop around for a lender?

[Woojin Joo]

When people shop for lenders, what does it look like in practice? Is it something that's typically done after entering escrow?

Will it require a hard credit pull for each lender I talk to to get an accurate estimate? If so, how will that affect my credit and loan estimate?

While in escrow, should I be calling around different brokers and/or direct lenders? And how many?