The strangler fig pattern helps migrate a monolithic application to a microservices architecture incrementally, by adding a facade between the old and new service.

The image below explains the process:

By adding a facade between the API and the service, you can migrate the requests redirecting them to the new service.

After all migration, you can then remove the monolith and the facade, completing the migration.

References

• https://learn.microsoft.com/en-us/azure/architecture/patterns/strangler-fig

• https://docs.aws.amazon.com/prescriptive-guidance/latest/cloud-design-patterns/strangler-fig.html