Dan Lewis, co-founder and CEO of trucking logistics start-up Convoy and a former Amazon executive, speaking at the CNBC Technology Executive Council summit it New York City on Oct. 29, 2019.

Dan Lewis, CEO of trucking logistics start-up Convoy, spent many years at Amazon before founding his own company. Among the biggest projects he worked on as Amazon's general manager of new shopping experiences was helping to build an online ratings and reviews model. It was a big problem from the online retail giant in its early days.

"The original problem we were trying to solve at Amazon was customer confidence. You can't touch, see, smell — how do you get confidence to buy?" Lewis explained at the recent CNBC Technology Executive Council summit in New York City.

Peer reviews, with a rating of one to five stars, solved the original customer confidence problem. But in that success, Lewis says he learned a key lesson about setting oneself up for failure, a lesson he vowed he would not repeat at his new company. In a nutshell: falling in love with solutions rather than never-ending problems.

"We didn't name the group that works on the problem the 'customer confidence team.' We named it the ratings and reviews team," Lewis said.

Amazon employees like Lewis who worked on the original solution became convinced their job was to make ratings and reviews better, instead of thinking of other solutions, and newer technologies, that could solve the problem better. It took other teams within Amazon disrupting them internally to build new solutions, such as ways for buyers to ask questions of merchants before making purchases, for Lewis to realize the magnitude of the problem. Amazon disrupting itself was a success — it just was not a success that was spearheaded by the original team problem solvers.

"Oftentimes you protect the thing you built versus remembering the existential problem you are trying to solve. Problems are evergreen. They tend to last for a long time, but the solutions that come along to solve them change and depend on the latest technology, and the thing every team at our company is trying to do is solve a problem, not make their solution successful."

"We've changed how we've gone to market several times in five years," Lewis said.

The approach is working for Convoy. On Wednesday, it announced a $400 million funding round co-led by Al Gore's investment firm that nearly tripled the start-up's valuation — from $1 billion to a reported $2.7 billion.