What project types best prepare students for real-world software engineering?

This question is too broad and subjective and isn't a good fit for this specific site that focuses on actual programming and software development problems. It's likely a better fit for https://softwareengineering.stackexchange.com/ or https://workplace.stackexchange.com/ where questions for academics and students, and career-related topics are permissive.

The question should still be more topical and reasonably-scoped in order to be answerable.

Perhaps one project could be an API Gateway and Rate Limiter ?

A service that manages and restricts API traffic to a protected backend service.

Technologies: Python or Java.

Real-World Engineering Challenges: Concurrency control, shared memory storage (Redis), traffic analytics, custom response handling.

Learning Value: Essential infrastructure skill, teaches about security, API management, and service stability.

What do you regard as a "typical beginner project" and why don't you think it will teach anything?

You can still teach engineering skills even if the finished product has no real-world use.