Product-related risks could refer to the definition and the actual development/ implementation of Minimum Viable Product. A poorly-defined product, regardless of how well-built, will probably fail to solve the problem and deliver value to its users. Poor implementation of a well-defined product will also fail to create value to the user. Engineering-heavy startups tend to put more effort than needed on the technical aspects of the product. You need to apply agile and experimentation principles, an effective way to improve your product and create value to your users.