Questions to ask to make sure you built a great Product roadmap

This is a very broad question. It depends on couple of dimensions : who your customers are and who your competitors are. Now depending on whether you are a product team, infra team or a services team, your customers and competitors will vary. The rest of the blog analyzes this from the perspective of a Product Engineering Manager

Product EM

Customers : Users
Competitors : Other industry products

Questions to ask

1. What is the mission and 2 year vision of the team?
2. Where does this put us in terms of competitor landscape in 2 years?
3. What are the latest trends in the product landscape that can disrupt the product? Examples : ride-sharing disrupted taxis, stories disrupted feed, mobile disrupted traditional camera, e-commerce disrupted brick and mortar. 
4. What is the strategy of the team that supports that mission/vision
5. How many customers(measured in MAU, DAU,WAU) and what is their level of engagement(impressions, clicks, sales, communication, usage, retention) needed for the north star
6. Reverse engineer into half over half goals
7. Ideate and prioritize(cost, confidence, impact) top engineering projects that can hit those goals
8. Roadmap should have a balance of short term, medium term and long term projects. There should be a mix of exploration and exploitation. The balance 50-50, 20-80, 70-30 may change half over half to compensate for new learnings and data as you go.