  Early in the pandemic, we -- leaders in the research areas of programming
languages (PL) and computer architecture (CA) -- realized that we had a
problem: the only way to form new lasting connections in the community was to
already have lasting connections in the community. Both of our academic
communities had wonderful short-term mentoring programs to address this
problem, but it was clear that we needed long-term mentoring programs.
  Those of us in CA approached this scientifically, making an evidence-backed
case for community-wide long-term mentoring. In the meantime, one of us in PL
had impulsively launched an unofficial long-term mentoring program, founded on
chaos and spreadsheets. In January 2021, the latter grew to an official
cross-institutional long-term mentoring program called SIGPLAN-M; in January
2022, the former grew to Computer Architecture Long-term Mentoring (CALM).
  The impacts have been strong: SIGPLAN-M reaches 328 mentees and 234 mentors
across 41 countries, and mentees have described it as "life changing" and "a
career saver." And while CALM is in its pilot phase -- with 13 mentors and 21
mentees across 7 countries -- it has received very positive feedback. The
leaders of SIGPLAN-M and CALM shared our designs, impacts, and challenges along
the way. Now, we wish to share those with you. We hope this will kick-start a
larger long-term mentoring effort across all of computer science.
