In my experience with mid size projects the key to success has always been controlling complexity. I can only imagine that this is even more true for large projects.
Generally the complexity an additional language brings to the table is immense in several aspects.
Specifically Rust has it's own problems and drawbacks.
Looking back at the history of Rust and Firefox/Servo, introducing Rust was overall quite a disservice.
No. Rust jobs are a niche - not even 0.1 % of the jobs out there. Most jobs are in frontend, mobile or standard business backends. So Java, C#, Python or Go are much better choices regarding job prospects and going to be for a long time to come.
In my experience with mid size projects the key to success has always been controlling complexity. I can only imagine that this is even more true for large projects.
Generally the complexity an additional language brings to the table is immense in several aspects.
Specifically Rust has it's own problems and drawbacks.
Looking back at the history of Rust and Firefox/Servo, introducing Rust was overall quite a disservice.