Pros
Unlimited freedom to push the boundaries. You are not faulted for your failures. Rather, you are encouraged to analyze and learn from your mistakes and become non-linearly better. You will work with the very best in industry whether it has to do technology or field or operations. People are kind and and will do whatever to help you. Your team has your back. Management is chiseled off a different stone. It is an environment that sets you up for greatness. Grit and determination can compete with sheer intellect to succeed at Xcalar -- you can have either and do very well; having both, a rarity, will be truly recognized.
Cons
This company is not for all. It's like joining the Special Forces. The pace, discipline and focus on the highest quality can be punishing. If you think that joining a great startup will take you some place better than where you are then this is not the right company for you. At Xcalar no one tells you when to come or when to go., but the culture of work is addictive. You end up pushing yourself to the limit and making sacrifices elsewhere. The company manages it resources very carefully. Think stock not cash.