Built-in exclusive locking

We have a (somewhat complex) process that is designed to be able to be executed completely async/parallel/multi-instance, except for a few Service Tasks that are sensitive and need to be exclusively synchronized, so that they are executed one-at-time (no matter what the number of started parallel process instances is).

Does Camunda offer a built-in mechanism to achieve this? Or is it expected to do this using other means, for instance using an external distributed locking system?