Today's entrepreneur: Sachin Agarwal

Posterous

BackType

I want to invent something cool.

Mixpanel, BackType, Groupon

The most rewarding part of working at a startup (especially a web startup) is how quickly you can push features out to your users. You can literally go from idea, design, implementation, and customer ship in a day. You won't get that speed at a large company.The most frustrating part is not having enough hours in the day to do everything you want to do. There are so many things you can build, so many great ideas, but you have to focus and prioritize.

Entrepreneurs make a ton of mistakes. I make mistakes every day. But that's part of what makes being at a startup so great.

One mistake I see quite often is when an entrepreneur doesn't build for "normal" people. What I mean is, they build software that makes sense to them, their friends, and the startup community.

But for non technical people, the software is way too hard to use.

Apple is the best at building very powerful products that normal people can just pick up and use. I'd love to see all entrepreneurs strive for that.

1. You have to build software that you are personally passionate about. You should build something that you use yourself every day or tackle a problem that excites you. If you find that you are building for users that aren't you or your friends, you're in trouble.

2. Ship early. It's been said many times but I think it's the most important lesson I've ever learned. The earlier you can ship something to users, the better. Then iterate as fast as possible. It's just too easy to keep building and never ship.

3. You HAVE to have work/life balance. It's tough. You will always think, "this quarter is hard but next quarter I'll take it easy." Nothing ever changes. There's no end to the work that needs to get done. So don't sacrifice your life totally. Make sure to spend time with your family and to stay in shape.