When Google’s venture capital arm poured more than $250 million into Uber in 2013, it looked like a match made in tech heaven.

Google, with billions of dollars in the bank and house-by-house maps of most of the planet, seemed like the perfect partner for Uber, the hugely popular ride-hailing service.

Bliss between the Internet titan and the hot young company, however, has proved fleeting.

Uber recently announced plans to develop self-driving cars, a longtime pet project at Google. It is also adding engineers who are experts on mapping technology. And the company, based in San Francisco, has been in talks with Google’s advertising archrival, Facebook, to find ways to work together.

Not to be outdone, Google has been experimenting with a ride-sharing app similar to Uber’s, according to Bloomberg. And both companies have long toyed with the idea of offering same-day delivery of items like groceries and other staples.