Abstract. After presenting some generalities on the congruence subgroup problem, I will focus on Prasad's work that completely resolved the problem of computation of the metaplectic kernel and also established centrality of the congruence kernel in many situations. Along the way, I will also explain Prasad's contributions to the investigation of strong approximation and the Kneser-Tits conjecture. 

Video: https://www.youtube.com/watch?v=lIQmCRxOc38&feature=youtu.be