Looking on the internet deeply has found these results:

I have just joined the company is the most popular phrase on the web.

I have just join the company 149,500 results on the web	I have just joined the company 149,800 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
My mother wants me to join the company. Couldn't just join the Boys Club, pal? Well, I'll just join the queue, then. I'm not asking you to just join the team. Please, just join the end of the line. 'Cause if you don't, I won't just join the war... I'll lead the charge. did you just join the Navy? Jack, did we just join the C.I.A.?	Iraqi patrol just joined the party. Mr President, I know I have just joined you, but I have been watching the monitor at a very important group meeting and I just wonder why we are not going seriatim. Among these are the new countries which have just joined the European project and which are among those suffering the most. You just joined the losing team. Now they have just joined the defense team of the Jackson Hale trial. This sharing is true for those who have just joined the EU and those who are going to join. I just have to go to this benefit tonight because my mother just joined the board of a new dance company. Of course, more needs to be done in future even in this direction, especially to respond to the request for solidarity voiced by the countries that have just joined the Union.

I have just join the company

149,500 results on the web

I have just joined the company

149,800 results on the web

More popular!

Iraqi patrol just joined the party.
Mr President, I know I have just joined you, but I have been watching the monitor at a very important group meeting and I just wonder why we are not going seriatim.
Among these are the new countries which have just joined the European project and which are among those suffering the most.
You just joined the losing team.
Now they have just joined the defense team of the Jackson Hale trial.
This sharing is true for those who have just joined the EU and those who are going to join.
I just have to go to this benefit tonight because my mother just joined the board of a new dance company.
Of course, more needs to be done in future even in this direction, especially to respond to the request for solidarity voiced by the countries that have just joined the Union.