I'm building a career coaching tool that will connect me with people who are for example ex-Google (my current company) and have had similar role as me so that I can receive a personalized and very contextual advice on how to scale up in this company. Do you think this is a viable idea?
I would recommend you brainstorm your idea by preparing a lean canvas. That way you will get a clear understanding of various other aspects of monetization, existing players, delivery channels, differentiators, etc.
I also had a similar struggle in the past. Then I finished a business coaching course by myself. This helped me to explore more new frameworks on business validation and building MVP.
I wrote a blog about validating your business idea without spending any money through Lean canvas. Have a look and you will get some clarity to build your own canvas for your idea. Happy hacking.
https://www.tham.xyz/evaluate-your-next-big-idea-with-lean-canvas/