I believe it means Apple/Amazon/Google/Facebook/Microsoft

I was also unsure and searching for it basically only gave HN things.

Apple, Amazon, Google, Facebook, Microsoft.

i.e. the big tech players that employ a ton of people and pay high, predictable salaries.

It sounds like a combination of Apple+Amazon+Google+Facebook+Microsoft.

Apple-Amazon-Google-Facebook-Microsoft would be my guess.

Apple, Amazon, Google, Facebook,Microsoft