This depends on what platform you’re working with. The three main players have extensive learning programmes to validate your expertise. For AWS, the foundation certificate is the AWS Certified Cloud Practitioner. After completing that, you can choose to take additional levels of certification, which are available for associate level and professional level in architecture, development and operations. You can also look at taking specialty certifications in areas like Big Data and advanced networking.
Microsoft Azure also has a number of certifications split broadly into three levels – Fundamental Level, Associate Level and Expert Level, while Google Cloud has its own training platform with Associate and Professional level certifications.