How to outsource a monolith?

Question

Outsourcing

Good day.

In the place where I work, a separate direction of development, a separate project, is planned, a rather large project is planned.
It is a problem to recruit people, so we are thinking of using outsourcing developers, freelancers.

Actually the essence of the question : how to do this and avoid draining the source?
Making a monolith means giving access to the entire project.
Microservices are simpler, ok, but to return to outsourcing, you will have to cut into services, roughly speaking, limited to 4 rest methods, and a bunch of sdk for all services for interaction. How to control this - no experience.
Logical microservices (such as: user account, file cleaning, messenger, project LC, internal processes) - again, "internal processes" and "project LC" will be quite large, and rather it can be attributed to a monolith.

Share your experience, as it happens in large companies, where even between departments they do not know about the work of another department

Answer 1

as an option to roll the application into nuget packages for example.
And give outsourcers only projects with connected packages.
Well, the most important thing is trust in the contractor and clearly defined boundaries in the contract