Good advice but I strongly disagree with technical advice #1. Testing and continuous integration are not that difficult to set up especially in today’s SaaS/PaaS CI world and taking time to automate process in general are well spent investments. Once these systems are in place they will surely return time and money with future deployments and should help reduce the amount of potential bugs within your infrastructure. I think it is wise not to go over board with testing, but to at least have some smoke tests for mission critical functionality.

I would be curious to hear about what metrics developers should measure. In a big company like Google it might be about reducing the time for the search results page to load, but back when Google was smaller it might have been about reducing the bounce rate. Google may have A/B tested a few different landing pages until they arrived at a lower bounce rate. Increasing revenue and profit are important but if you have a high churn rate of subscribers its probably worth investing some thought into figuring out why customers are churning and work towards correcting that metric or pivoting into a new idea.