Datadog uses PostgreSQL. See [1].<p>[1]: <a href="http:&#x2F;&#x2F;www.enterprisedb.com&#x2F;success-stories&#x2F;postgresql-success-stories&#x2F;datadog" rel="nofollow">http:&#x2F;&#x2F;www.enterprisedb.com&#x2F;success-stories&#x2F;postgresql-succe...</a>