Having just launched a software product myself I realize that the work we did before starting the project was the most important work we did. Before you begin developing a software product you need to answer a few questions first:

1. What is the demand for your product?
2. Who are your competitors?
3. Who currently owns your audience?
4. What is your MVP Minimum Viable Product?
5. What is your MMP Minimum Marketable Product?
6. How will you monetize your platform?
7. Who are the influencers in your product audience?

I think there's a lot that goes into this besides creating a roadmap. I think your first focus needs to be to answer the above questions and then decide how you want to move forward. Then you can move into a roadmap, finding the skillset you need to develop your product, creating a marketing strategy for your product, creating effective demand and scarcity for your product launch, etc...

Hit me up if you need additional help. I'd be happy to chat with you about this.