1) The whole team is growth focused, but I'm the only who helps guide and lead the strategy but for the most part, we know our core metrics and we have a development process for reviewing / assessing / testing / adjusting, etc. So I guess that's me.

2) We have many tools, and all depends on the metric, funnels, etc. As a general rule of thumb we use Google Analytics for all external traffic converting to sign-up, Mixpanel as a data warehouse for all events & funnels, A LOT of custom reports and tools we've built in house required when MixPanel or Google Analytics falls short.

3) We actually use Clarity (whole team) for conducting usability testing with members & experts on specific topics. We create clickeable prototypes and use Clarity to schedule a call & www.join.me to share the prototype for feedback. We also use www.usertesting.com for odering weekly baseline videos on our mobile app. It's not a "tool" but we use the Jobs-to-be-Done framework for conducting interviews when trying to understand intent.

4) Dave Skok has written the bible in my mind when it comes to SaaS metrics http://www.forentrepreneurs.com/saas-metrics/

Hope that helps, feel free to request a call to discuss further.