Found the following solution:
Add job level parameters:
parameters:
- name: run_timestamp
default: "some_default_value"
Reference in task level parameters:
tasks:
- task_key: my_task
spark_python_task:
python_file: ../../script.py
parameters:
- --run-timestamp
- "{{job.parameters.run_timestamp}}"
Deploy to Databricks and override default value of job level parameter when triggering the backfill runs.