Which service is specifically mentioned for sending notifications through custom workflows?

PagerDuty is specifically mentioned as a service for sending notifications through custom workflows. This platform is designed for incident management and alerting, allowing teams to respond effectively to issues in real-time. Its integration with custom workflows enables organizations to automate notifications and escalate issues according to predefined protocols, making it a vital component for operational efficiency in many IT and security operations.

While Google Chat, Slack, and Zoom are valuable communication tools that can facilitate collaboration and communication, they are not primarily designed as notification services within the context of custom workflows. Instead, they function more as platforms for messaging and videoconferencing, which can enhance communication among team members but lack the specialized features that PagerDuty provides for incident notification and management.