Is it possible to switch to a role in cloud computing after 9 years of experience in a different domain? What advice would you give for someone who wishes to do so?

It is possible once you up skill and and get certified (certification is a good addon when changing lines).

Yes it is possible as long as you put your mind into it! Approach that I see working for others:
1) Self Assessment.. Evaluate your skills and knowledge and identify transferable skills that can use used in cloud universe. For example, project management, business analysis, security, etc.
2) Research. Explore the different areas of cloud computing and the various roles (security, project  management, architect, engineer, etc). 
3) Gap Analysis. Compare your existing skills and knowledge with the role you are considering. Identify knowledge/skills gaps. Prioritise the top ones required.
4) Training. Find training courses that are relevant to the role you are considering with focus on key skills required.
5) Hands on experience. Look to get some hands on experience, starting with Labs (offered by all major CSPs).Also consider internships, open source projects, volunteering or freelancing. 
6) Networking. Join online communities, become active, meet people in the industry.

It take a strong a will to shift from domain to another. If you got that will, then everything else is easy!

Best of luck!

Try to discover gaps, where you can bring in your experience from your previous role. Not all domains are developing equally and by people, switching between domains, a know-how transfer can be achieved.

Yes, totally possible. Start with small things and start learning about cloud basics. Then go for some certifications and hands-on is mandatory. Internal job switching is always easier and can help. Getting a job outside just on the basis of theoretical knowledge is difficult. Might have to do some compromise in terms of band or salary