Headless Android App Automation (No GUI / No Emulator UI)

I am looking for an experienced developer to automate a registration and reservation workflow inside an Android application.
Important:
* The automation must run without GUI interaction (no visible emulator or manual interaction).
Preferred approaches:
* API-level automation (if endpoints can be used directly)
OR
* Headless Android emulator controlled via ADB
OR
* Programmatic interaction using approved automation frameworks
Scope of work:
* Automate form submission
* Handle validation responses
* Implement retry logic
* Log responses and errors
Requirements:
* Experience with Android automation
* Knowledge of reverse engineering network calls (if applicable)
* Clean, stable, and maintainable code
* No modification of the original app binaries
Please include:
* Similar previous work
* Proposed technical approach
* Estimated timeline