Here’s a major problem with being a non-technology founder and using an agency to build your MVP.
There’s more technology in a technology business than just the product. In particular, there is a ton of “IT” stuff that you need to build related to actually growing the business.
You can get so far hustling on an ad hoc basis, but ultimately you will need proper marketing automation and sales automation, and you sort of need to grow the business around those systems and segue them into the actual product to create a cohesive experience.
Among the problems that non-technology founders have with software agencies is this issue that they will take a specification and try to build a working product around it, but that doesn’t get you a business, it just gets you a product.
There are a lot of “growing pains” for non-technology founders using agencies – one of them is weaning yourself off using the agency and having your own team, another is this issue that you need to start building out in-house systems to scale the business.