Two year employee

At Amazon, the entire company is built around the idea of a 2-year employee. There is a phrase in the company called "The Golden Handcuffs" - the stock bonuses that mature years later such that you're always leaving something on the table. Benefits, training, bonuses, everything is built around keeping an engineer for two years - and less than 2% of employees make it past that point. If Amazon will ever hope to gain the benefit of the knowledge and expertise of longer term employees, they're going to have to treat employees very differently.