Matt Williams 
Pro gives people instant price estimates for any home improvement project (tailored to their zip code) and helps them schedule verified professionals to complete that project.
Now, its service will integrate with Build to let customers easily pick out the materials and products they want to use from its database of 700,000 options.
The idea: To give people a complete understanding of how much any given home project will cost, and then give them all the tools they need to order the right materials and schedule a professional to get it done.
Led by Matt Williams, the former Digg CEO, Andreessen Horowitz entrepreneur in residence, and long-time Amazon employee Pro launched in May after raising a $3.5 million round of funding from Madrona Ventures, Andreessen Horowitz, Bezos Expeditions (Jeff Bezos' personal venture capital firm), and others.
What seems like a simple process on the surface - users simply visit the site, enter any project they need done, fill in their zip code, and get a price estimate - is the "tip of the iceberg" of an incredibly complex system. Pro's team needed to refine its natural language search and figure out an algorithm (based on tons and tons of research) for adjusting different professional costs across the country.
Williams told Business Insider that over half of Pro's 30-person team has worked at Amazon at some point, and part of what makes the team so strong is its members' robust engineering background.
"We're as much a search engine as a home projects system," Williams said.
Although Pro has vetted professionals all across the country - and started getting thousands of cost estimate requests soon after launching - the full scheduling product is only available in Seattle for now.
Eventually, Williams sees Pro's system offering services for more than just home improvement projects. The idea of delighting customers has been ingrained in Williams thanks to his 12 years working at Amazon in various roles (he even shadowed CEO Jeff Bezos for a while). Williams joined the company after his startup LiveBid was acquired in 1999.
When asked whether he's nervous about the rumors that Amazon itself could be launching a local services platform, Williams played it cool. There's enough room for both of us, he says.
As part of this new partnership, Pro.com users will receive a 5% discount from Build.com on their first order.
Disclosure: Jeff Bezos is an investor in Business Insider through his personal investment company Bezos Expeditions.