The list of services they provide should be examined to determine whether they can meet your needs, and case studies should be examined to determine whether they have experience working on projects similar to yours.
Then, you might wish to read customer reviews to evaluate their dedication, work ethic, and communication style. In addition, you can discreetly inquire about their experiences by getting in touch with the business's previous customers.
In order to prevent any of your sensitive data from being leaked to rivals, your potential IT partner should be willing to sign an NDA.