If Uber, Lyft, Pinterest and Slack go public later this year, as is expected, it will be the culmination of months of work. Executives will have to do everything from preparing financial statements for release to editing revisions to their prospectuses. On roadshows around America and possibly overseas, they will try to convince big investors to buy their stock. Then comes listing day, a potential marketing bonanza with a lot at stake.

Company executives won’t go at it alone, of course. In key sessions will be bankers, lawyers, and advisers from audit, investor relations and communications firms—each of whom will emerge as winners if their clients pull off successful IPOs. Here we detail which firms in these categories are likely to feature prominently.