The strangler fig pattern was introduced by Martin Fowler as a way to manage risk when modernizing or rewriting large, monolithic systems. The pattern is an analogy for a type of plant that begins life as a vine growing alongside an older, established tree. As the vine grows, it spreads to completely consume and ultimately replace the host tree, leaving a new, strangler fig tree in its place

Follow these best practices when using the strangler fig pattern, so you can independently scale and deploy your application more smoothly:

Select a component that has good test coverage and less technical debt associated with it. Starting with this component can give teams a lot of confidence during the modernization process.

Select components that have scalability requirements, and start with one of these components.

Select a component that has frequent business requirement changes and frequent deployments.

To implement this pattern at scale on AWS, deploy the refactored ASMX services in a Windows container that is running in Amazon Elastic Container Service (Amazon ECS), and publish your modernized REST API by using Amazon API Gateway.

https://docs.aws.amazon.com/prescriptive-guidance/latest/modernization-aspnet-web-services/fig-pattern.html