As part of my career advancement strategy, I am heading down the technical track of software development (as opposed the managerial track, in case anyone is wondering). 

For all the Principal/Staff/Lead Software Engineers ...

1. What advice do you have for working toward that goal?

2. Knowing what you know now, would you do anything different as part of your journey to your current role?

3. What concepts/designs/educational material have been instrumental in obtaining your current role?

A bit of background, I am currently at a Senior level and have been in full-time software development for about 4 years (I have about 7 years of prior IT experience). I've primarily developed web apps in the JavaScript space (TypeScript, React, Vue, Node, etc.) and have some experience in various cloud environments and using some strongly-typed, OOP languages such as Java and C#.

If any additional context is necessary to help answer the above questions, I'm happy to answer them. Just tag me in a comment. 

Thanks!