Chapter 11 starts from soft assignments in Gaussian mixtures, uses Jensen's inequality to construct the ELBO, interprets EM as alternating maximization over a variational distribution and model parameters, and extends the idea to VAEs through approximate posteriors and reparameterization.
CS228's official prerequisite is a single line — 'basic probability theory and algorithm design and analysis' — with no named course. But ExploreCourses shows it was last offered in Winter 2024, and the next slot, Winter 2027, still has a blank instructor field. What a self-learner can actually get is cs228-notes: 16 chapters, complete, last touched in June 2025.