When it comes to achieving product-market fit there is nothing more effective than talking to customers, however, it seems like there are different ways to approach Users. The YC way, where you build an MVP -> launch early -> talk to customers -> iterate till you find PMF -> scale. (Airbnb, Doordash..etc)
The Lean startup, on the other hand, focuses more on understanding the problem/solution fit first then build an MVP to validate PMF then to scale. Their flow is like: talk to customers, validate the problem-> talk to customers, validate the solution -> build MVP sell to the customers -> build product to scale.
What are your thoughts on this?