So I am familiar with designing the schema of a relational database using PHP. I've hired a Ruby on Rails agency to make a web app. I've been asking them to provide me the schema design and run all changes to the schema by me. (The app has a lot of details that I can tell they don't have a strong grasp of and I want to make sure they're not relying on a schema that has errors in it/ needs to be changed as later specs get implemented). They have danced around my request for the past week and today ended up telling me to "not worry" because they use migrations and any mistakes made with one migration can I am assuming be fixed with another. This is not reassuring – at all. It also comes across as a red flag to me. I pointed out some incorrect attributes they had as part of an object and you would think that would teach them to reach out to me to verify what they have / proactively confirm any changes they want to make with the schema.. but they are very stubborn on not doing this.
What is the professional process for putting together a schema for a RoR app? Is this cowboy approach they've got going on actually accepted / the standard in the industry? If not, what process should they be following? Like I said, I have designed relational databases in PHP and I am used to a more ordered approach to creating the schema, not a cowboy/fix things as they are broken approach. Advice is appreciated.