AWS Instance Troubleshooting

I need help with my AWS instance that won't start. The issue began after I changed the instance type. I'm looking for a professional who can diagnose the problem and get my instance up and running as soon as possible.

Ideal Skills:
- Extensive experience with AWS
- Proficient in troubleshooting cloud-based instances
- Knowledgeable in instance type configurations
- Able to work under pressure