Pros
The company is truly progressive, not just in what they said, but in their actions. Employees are encouraged to express their opinions freely, whether they are positive or critical, and regardless of whether they're in direct opposition to leadership. One of the first things I noticed about Atlassian when I was interviewing was how many people have been there for 5+ years; Ive spent the last 5 years in software and I've never seen this anywhere else. In working at Atlassian, I understand why this is - there are a lot of opportunities for growth and incredible benefits. My manager has been really supportive of me doing more of everything I enjoy and less of everything I don't enjoy. I plan on staying with Atlassian for as long as I can (10+ years). I have incredible work/life balance and this is something the company supports wholeheartedly.
Cons
Working for a company this large can be pretty confusing, especially if you're coming from a smaller compan. The size of the company is both a blessing and a burden - because of its size, there are a ton of resources; however, with so many employees across so many teams and so many locales, figuring out exactly who to speak to about specific issues can be challenging. Also, the company currently determines salaries based on the going rate for the market each employee is based in. A lot of employees have expressed criticism about this and I'm hopeful that this will change in the near future.