Just to brag a bit: I actually had a successful factoring session with Colab using the GPU branch of GMP-ECM for stage 1 and a local machine for stage 2.

It was only a 146 digit number and it took quite a while, but still, it worked!

Colab connected me to a T4 which gave me 2560 cores on which I ran stage 1, with the -save option. The local machine "watched" for the residue file, using the tunneling setup by chalsall, described elsewhere. The local machine used ecm.py by WraithX to run stage 2.

A minor session, but it proved the concept.:smile: