In terms of the practical realities of organizing developers, check out Tech Solidarity or your local DSA branch. Both groups are deeply involved with helping workers organize and restore a sane power balance to the American economy.
I’d like to echo the sibling comment to visit your local DSA branch if you want more information.
Look at the school walkouts in the United States lately.
Helicopter video on the news of 1,000 Googlers marching out of their offices would do a lot more to raise the nation's awareness of the issue, and put a lot more pressure on the C-level, than an internally-circulated letter.
Unions are great, when they are great.
The West Virginia teacher strikes were wildcat strikes, meaning they did not have the support of their union. The union was against the strikes but the teachers had the support of their community, which is far more important.
In short, and due to the recent Janus Act, unions in the US are not going to be very helpful for a while. But, more important is building a popular consciousness ready to articulate these struggles within a capitalist system.
DSA has a few very positive tech-focused organizing efforts underway in SF and NYC. I recommend starting at http://dsausa.org