My team and I use HackerOne for coordinated vulnerability disclosure and triage for cloud and enterprise infrastructure, which includes AWS, Azure, or on-prem, focusing on IAM, network exposure, misconfiguration, and remediation across multi-customer environments.
An example of how we have used HackerOne for vulnerability disclosure in our environment is that we use it to receive and triage reports on publicly exploited exposed cloud assets.
An additional use case for my team with HackerOne is that we use this product for centralized intake for external security findings, prioritizing based on asset criticality, SLA-driven remediation tracking, and audit-ready reporting for cloud and enterprise infrastructure across multiple customers.