MoxiWorks has a hybrid infrastructure, using two physical datacenters, AWS, and Azure. In addition to bare metal, they run Linux VMs under VMWare, KVM, Proxmox, and EC2. They also run docker containers directly under ECS, and are in the process of migrating to EKS. Most services run under Rails, with some WordPress, .NET, and Java.
I was the DBA for our PostgreSQL servers, which is used by the Rails apps. MoxiWorks runs PostgreSQL clusters on bare metal, on VMs (both on-prem and in AWS), in RDS, and in Aurora. I was also the DBA for our MySQL and MariaDB servers, which are the backends for the four WordPress farms.
I was also primary on DNS BIND, which MoxiWorks uses to host roughly 15,000 domains.
I also supported the rest of the data center infrastructure, including networking (Cisco), disk (Netapp), Hypervisors (KVM/VMWare/Proxmox), hundreds of VMs, Redis, Memcached, Elasticsearch, and HAProxy.
I participated in the 24/7 on-call rotation, usually one week in five. Additionally, when not officially on-call, I would be called in to help resolve production issues.
I migrated servers and services into AWS, and was part of the team supporting the wide range of AWS products MoxiWorks uses, including SES, EC2, ECS, S3, VPCs, EKS, Transfer, and EFS.