For PhD students specifically:

  1. OpenReview: ML deadlines plus your submission history in one place.
  2. WikiCFP: broadest CFP coverage across CS.
  3. Google Scholar alerts: your keywords, your inbox.
  4. Conference Alerts: set-and-forget email digests.
  5. Your advisor's forwarded CFPs: still the highest-signal channel.

The PhD-specific trick: maintain a personal venue shortlist of 6 to 8 conferences, ranked by fit, with their typical deadline months. Update it yearly with your advisor. Every paper then gets a venue in an afternoon, not a month of dithering.

Introduce new PhDs to the tracking system in week one; deadline literacy is a lab skill, not a talent. Sources: IEEE, ACM Track calls, but also track outcomes: which venues accepted your lab's papers, with what acceptance rates. Your lab's history predicts your chances better than any global statistic. The best app is the spreadsheet your senior labmates already maintain. Ask for a copy.