People often ask me to compare working for Bezos vs Zuck. I worked with Mark much more closely for much longer, but I did work directly with Jeff in my last 2 years at Amazon incubating the Kindle. Here are some thoughts on similarities that make them both generational leaders:

Jeff was 30 yrs old when he started Amzn, and he was 35 by the time I joined in '99. Mark started FB at 19 yrs old and was 22 when I joined in '06 (and is now 36!). After I joined FB, I shared with Mark that I thought he most closely resembled Jeff among all the tech founders.

They both lived in the future and saw around corners, always thinking years/decades ahead. And at the same time, they were both obsessive over the tiniest product and design details. They could go from 30,000 feet to 3 feet in a split second.

In the best tech companies, product defines strategy and culture. Jeff and Mark were both product CEOs first and foremost (though Jeff is arguably more commercial). Amazon and Facebook’s products are also an embodiment of Jeff and Mark’s individual personalities and values.

Neither of them would ever dwell on success. Every time I took a hill and looked up to celebrate, Jeff or Mark had already moved on to the next hill. They set unrealistic goals and were insanely intense, disciplined, hard working and hard driving.

At the same time, they each had a great sense of humor (albeit with very different styles). When you're working tirelessly and driving people really hard, it's important to break it up with occasional bouts of levity. I laughed a lot around them.

Both of them engendered profound loyalty from their teams. The senior folks at Amazon & Facebook have been there for a very long time, mostly because they couldn't imagine working for anyone else. When you get to learn from one of the greatest, it's hard to leave.

They were both incredibly deep thinkers and read voraciously. I've participated in small group conversations with each of them (eg on airplanes) lasting hours where they would ask endless questions and have more stamina than anyone else. Great leaders have deep-seated curiosity.

The skill set required to start a company is insanely different than being CEO of a mega corporation. Scaling of this magnitude requires tireless commitment, crazy focus, thick skin, unbridled ambition. You have to be a learning machine, constantly growing and pushing yourself.

Their personalities are obviously quite different. Jeff is gregarious with his big laugh and well-honed stories. Mark is more quiet, gracious, kind; sometimes a bit awkward but always authentic. When Jeff is unhappy he will throw you out of the room; Mark simply ends the meeting.

The cultures they built are also very different. Amzn is more siloed/secretive, while FB is radically open/transparent. There are pros and cons to each (which I will cover in a future post), but culture at both companies runs deep and is rooted in the values of the founder.

I feel fortunate to have worked for two of the greatest founders in history. I sponged knowledge and rode each of their coattails as they built iconic companies. One of things I most enjoy now about being in venture capital is sharing what I learned from Jeff & Mark with others.