The Wikimedia Foundation is a terrible place to work. It's completely averse to change, despite management saying they are open to constructive feedback (do not fall into this trap, you'll be shunned by your manager and their followers). They have great values on paper, there is a lot of talk about excellence but it's all make-pretend. You'll see new hires coming and going, frustrated that they are at the place with the best mission ever but the worst workplace culture. If you care about your skills and careers, think twice.
Flexible hours, travel, mission
Vague goals, politically charged environment, averse to change, bad practices