Any way to trigger ECS Task on S3 upload *without* Lambda?

Problem: Trigger an ECS Task on object upload to S3. This AWS tutorial makes it seem like it is possible, however there does not seem to be much information about how to do emulate this using the Serverless Framework.

Constraint: As explained in this AWS tutorial, trigger the ECS task without using an intermediary Lambda

Disclaimer: I am very new to serverless (both the technology and this framework) so I may be misunderstanding something fundamentally. Nevertheless, I am super eager to learn and build with these incredible tools and would appreciate any help/guidance!