Leave. Unless you really love the company. Then talk to you manager/anyone who has an impact on future projects about this, ask what the plan is to prevent this, and then leave.
Deadlines are typically not strict unless there is a contract in place. They can be moved. Asking people to put in some extra time once in a while is fine, even if not ideal, but not for extended periods of time. That leads to burnout and the company is valuing delivery over your health and your future ability to work for them.
Deadlines are typically not strict unless there is a contract in place. They can be moved. Asking people to put in some extra time once in a while is fine, even if not ideal, but not for extended periods of time. That leads to burnout and the company is valuing delivery over your health and your future ability to work for them.