How do we validate that our product strategy is the right one?

This is a natural question and I would specify the question a bit to say "how do we validate that our product strategy is the right one for us?" 

Might seem like a small delineation, but the truth is, no one strategy is right for every company or product. What works amazingly for one company could yield paltry results for another. 

For that reason, I'd say the best starting place to determine whether you're developing a strategy that is right for your situation is

1. To be clear on the first principles you're designing around
2. Try your hardest to maintain an environment of intellectual honesty that normalizes healthy friction (by healthy friction, I mean people care, are not afraid of unnecessary repercussions for sharing original ideas, and communicate in a compassionate way with one another) 
3. Have a bias for action instead of perfection

Every strategy looks great in a deck or on a whiteboard, but you have to be willing to put something out there and see what the world tells you. To paraphrase Mike Tyson, everyone has a plan until they get punched in the mouth. If you've designed your strategy from your principles, aligned them to your goals, brought people along the journey with you, and aren't afraid of changing your mind due to feedback (👊🏾 ), you'll be able to inch yourself closer to what's best for your company.

First, define "right" by establishing clear goals – is it product-market fit? Is it growing an existing product to a certain milestone? These will help you determine the right form of validation to apply to each stage. 

For products that haven't yet achieved market fit, early & rapid customer feedback cycles are the best form of validation I've seen – push your target users to tell you over & over again in surveys & interviews that what you're building is something they must have, ideally by getting them to sign up or even pay you before you've even built it. 

Once you have a clear sense of your goals after product-market fit, figure out what inputs drive those outputs – for example, if your goal is 10x growth in total customers in a year then maybe you need to significantly grow your weekly signups. And if your product initiative is to reduce the number of steps in your signup flow, then your target metric is likely to be improving conversion at the end of that flow. Once you implement your product initiative, test whether it's hitting your goal and iterate rapidly until you find the best path forward. 

Pick the right input metric for each product initiative based on the goal for the initiative & track it closely to figure out whether your product strategy will get you to your goals.