Best Unified API for Read and Write ATS Integrations

Unified's ATS API provides a streamlined solution for integrating with multiple Applicant Tracking Systems (ATS) by offering a consistent set of objects and endpoints, minimizing the complexity typically associated with individual ATS integrations. This unified API allows for efficient management of core objects such as candidates, jobs, applications, and interviews, while accounting for provider-specific variations in authentication, object models, and write constraints. The API supports both native and virtual webhooks to ensure reliable event delivery, with polling used when native webhooks are unavailable, though the latency may vary depending on the provider. By normalizing ATS objects and allowing for provider-specific fields when necessary, the API reduces engineering overhead and enhances the developer experience with SDKs, authorization components, and observability tools, ensuring that teams can maintain robust integrations without extensive provider-specific code paths. The service emphasizes real-time, pass-through data processing without persistent storage, offering comprehensive support for 68 ATS platforms like Greenhouse, Lever, and JazzHR, while clearly documenting provider-level write constraints to enable intentional, scalable feature design.