I have used this solution for one year. 

I've been using this solution for over five years. 

In my portion of the company, we've been using it for about six months, but we've had it for a couple of years in other portions.

We have been using this solution for three years. 

We've been dealing with Couchbase just very recently, approximately two months now.

I have been using Couchbase for three years.

Currently, I am using version 6.0.

I have been using Couchbase for approximately two years.

We have recently started using the solution.

I have been using Couchbase for six to eight months.