Usually there is no problem in working again for a previous employer, as long as it is good for you.
For example, I was in a company where I had stagnated, where I was the unofficial leader of the team but was trying to make it official. Since that would involve payment raise, I was having trouble achieving it.
I then received an invitation to join another company as a team leader and accepted. However, the job was not what I was told it would be, and I started having to do a lot of overtime. For the first 9 weeks in this new job, I had no weekend, for example.
Failing to solve that issue internally, I started looking for a new job five months later. My previous employer discovered and called me to talk and offered me the leadership of my previous team.
Then I returned and stayed there for 3 years, and it was good for both parties.
So, short answer, if it will be good for you, and you know why you are choosing it over the tech giant, go for it. If, however, you are a little concerned of going to a new place and would feel more comfortable going to an already known place, maybe you should reflect more before deciding.
good luck :-)