Work life balance is frowned upon. If you're not in the office late into the evening and answering emails on the weekend you're not working hard enough.
Good luck trying to focus in one of the worst open floor plan offices I have ever worked in. Row after row of bench style desks where stretching your arms might mean an awkward apology to the coworkers sitting on either side of you less than 3 feet away. They typically cram 50-100 people in a given area with no barriers, not even half walls, so you spend the majority of your working day trying to drown out the distractions.
Management is unprofessional and frequently in a position just one level higher than they should be. There is no coherent vision for the company except ignore what's best for the users if it means money can be made.
Finally, there's a reason why Twitter reported the worst representation of women in technical roles (90% male, 10% female). This place is a brogrammer haven. As a woman your faced with a culture that screams petulant college bro from the first day you walk through the doors. Women are frequently given work of lesser importance, have their ideas attributed their male colleagues, are passed up for promotions, and generally made to feel unwelcome. To top it off the women's organizations within Twitter carry no real weight at the company. They are open to all employees so women don't have a safe place to talk about the serious issues facing them without it being made into some kind of joke by male engineers or used against them later.
