A software product is hard to see, so the site has to explain it. Lean Labs' article on B2B SaaS website design advises a clear product message, navigation people can use, a layout that works on a phone, a way to measure results and a defined path from first visit to conversion. Those are jobs for a strategist and a writer as much as for a designer.
Suppose you sell scheduling software to outpatient clinics. An operations manager finds you through a search, reads the homepage and wants to know what the product does, whether it connects to the clinic's records system and what it costs. Assume the next step you want is a demo request, sent by a form to your CRM for a sales rep to pick up.
That path sets the brief. The homepage needs a message a clinic manager understands in a few seconds, which is a writing job. The integrations and pricing pages have to be designed, and the demo form has to be built so the request reaches the right rep with the facts sales needs. The firm you hire should be able to show each of those in a site it has already launched.