On occasion, and this was rare - the servers would go down, so the team was unable to utilize the platform. This would never last more than a few hours, at most. I'm sure the developers at Bullhorn work hard.
There are also filters and features that are a little excessive- however since the database is so modifiable - you can either exchange the fields or disregard features completely. For me, largely an administrator as well as a user - found the arrangement of data useful and the analytics incredible.
Lacking in the ability to parse a resume with graphics - since the plugin would pull text without formatting; any Word document or other CV or resume file that was built with comprehensive graphics or tables would fail or appear jumbled. There was the ability to program in a company letterhead and footer, pull identifiable information from the candidate's document... but it never worked to the point of being client-ready. I lacked the coding chops to program it - would have involved to get it right (pull text, page breaks, general HRXML etc.) For what it's worth, the system is accessible and with enough customization available that one day I could have fixed this process.
(I'm not sure if this is contract specific - but hosting graphics online publicly, even for a simple logo - wasn't really an option either).
Finally, it was also difficult to search the database in BOOLEAN - which is worth learning as a practice but not necessarily easy to master. I know a few team members had voiced complaints about this. It is probably the most specific approach to data search, though. Review collected by and hosted on G2.com.