An application for a recruiting firm has an external system of record (SOR) for candidate work experience. The candidate work experience SOR supports an API for reading but not updating data. You are developing a job application case type. Candidates must add relevant work experience when filling out job applications. Returning candidates must be able to pull work experience from the external SOR, make changes if necessary, and push these changes back to the SOR. Which integration option do you use to address this use case?
1) Database Integration
2) File Integration
3) Web Service Integration
4) Messaging Integration