“WE REALLY f***ed up.”

This is the confession from a disillusioned former Google staff member.

Developer Chris Messina, who invented the hashtag and spent three years helping create Google+, has written a scathing blog on Medium about the tech giant’s “failure”.

The brutally honest post details his view about how Google+, which was meant to be a one-stop home for Google users’ online identities, instead turned into a copycat of Facebook, CNN reports.

Messina, who left Google more than a year ago and joined a start-up company, wrote: “Lately, I just feel like Google+ is confused and adrift at sea. It’s so far behind, how can it possibly catch up?”

He said Google+ was meant to stand out as a trusted base for users to share information about themselves with only the people they wanted to see it.

“What’s sad to me is that the promise of Google Me (the original name for Google+ internally) could be found in launch post: ‘We want to make Google better by including you, your relationships, and your interests’,” Messina wrote.

“It was like Google was saying, ‘We’re going to be your trusted partner in cyberspace, and we’ll help you surface the right information to the people you choose, at the right time’. It was a functional search-oriented value proposition, rather than a social networking one.

“Thus, for me, when I searched for my mum’s phone number on Google, I actually find it — because it would be on her profile and she would have shared it with me. Suddenly a query like ‘mum phone number’ would work.”

Instead, he says it became a kind of “Facebook- lite”.

“Why did the world need another Facebook, unless to benefit Google by making their ad targeting more effective?”

He went on to point out that Google+ launched a polling ad unit five years after Facebook did (in 2009). He also criticised the company for its lack of innovation, saying Google+ and Hangouts apps have been updated half as often as YouTube and Chrome (six updates versus 15 and 16 respectively). It’s way behind Facebook, which has had 19 updates, Instagram with 29 updates and 33 for Twitter.

Ultimately, it was all “too little, too late” for Messina, who says he’s ashamed to admit to spending years on a tool he believes will become irrelevant.

But Messina wants Google to succeed, to provide competition against Facebook. He says there are plenty of resources and strong leaders in the company, so they should be able to succeed.

news.com.au has contacted Google for comment.