The timing of this question is fantastic, we are actually implementing password-less email login right here on Hashnode. It should be available to you in a couple of days.
We'll come up with a story on its merits, but for now let me just say that the days with email and a password are long gone. You need to remember a password for starters when you have one and from an engineering perspective, you need get into hashing (and other jazz) to store your password in the database. A password-less login will ideally be based on a link that's generated on the fly when you want to log in. The moment you login, the link is destroyed from the database, making the sign in process super secure. I'll link the story we're working on to this question as soon the feature is live on production.
Slack, Basecamp and Yammer are some products that have already done this (in fact, they inspired us to implement this feature).
any progress on this?