Pros
Most if not all Atlassian employees truly live the company values. Everyone works hard to make this a great place to work, with lots of places to find "your people" and for individuals to add to the company culture. Product and marketing teams genuinely seek to be the change you seek while still balancing periodic waves of feedback and navigating several sources of feedback from customer-facing teams.
Cons
While Atlassian is truly a wonderful place to work, I've seen people become too comfortable and stop pushing themselves to do "the best work of their lives". Experiences with recruiters have been hit or miss internally and externally with seemingly little incentive to progressing employees with internal mobility outside of stats by functional group. Career success and growth seems to be mostly based on the initiative and drive of the individual and their connections rather than something that is front of mind for some managers.