Don't believe all of the negative press
Pros
Having worked at Facebook for a number of years, and having experienced many other companies prior, I am still incredibly proud to work at such a company that values its employees, is so open and transparent, and that has a mission I truly believe in. Speaking with a number of employees who left Facebook only to return once again, while no company is perfect, there is a lot that Facebook has to offer - not just in terms of benefits, but with the impact that our apps and services have on this world - for people and businesses alike. Our open culture is pretty amazing to understand the vision of our company and where we're heading. Leadership has been consistently transparent in ways that many other companies are not - even other tech companies - with weekly Q&As, open posts, and quarterly all hands. And they address tough issues or topics head on. There are a lot of career opportunities within the company - as we often refer to the "jungle gym" that you can take your career internally. There are incredibly passionate people who work at Facebook, and I never cease to be amazed by the level of intelligence and care demonstrated by my coworkers around the world to help our company deliver on our mission.
Cons
Particularly as of late, Facebook has been subject to a lot of negative press. While some of it may be deserved, a lot of it feels sensationalist. So employees have to develop a thick skin and resilience to a lot of this scrutiny and ensure that we are focused on the long-term, not just the short-term. But perhaps the primary area of improvement is that people are driven and work hard - which sometimes comes at the expense of the work/life balance that we all try to achieve.