Embedded in DeepLearning.AI courses on Coursera under the last week of each specialization. You will find a link to a form where you can express your interest to volunteer as a mentor for that course. If you sign up using the form, you will be contacted before the next cohort of volunteer mentors begins.
If you are found to be a top contributor in terms of the learner queries you answered, likes received to your replies, and number of accepted solutions you posted, you may be recognized for your efforts, and also offered by DeepLearning.AI staff to become a mentor.
If you wish to sign up to become a mentor of a specialization you’ve completed apply here.