Infrastructure I can explain
I like infrastructure that one person can understand end to end. I run my own, and that is how I learn what breaks.
Virtualisation and compute
I use Proxmox VE to run virtual machines and containers for my own services and experiments. Working with real hypervisors, instead of only a cloud console, is what taught me where the failure modes are: storage latency, memory pressure, a node that drops out.
Storage and data integrity
TrueNAS with ZFS is where I keep data I cannot afford to lose. ZFS checksums and scrubs catch silent corruption, and snapshots make rollback cheap.
Containers and orchestration
Docker Compose is enough for most of what I ship. For clusters I use K3s, a small Kubernetes distribution, when a workload needs scheduling across several nodes.
Choosing ownership deliberately
Self-hosting is a trade, not a creed. It removes subscription dependency and keeps data on hardware the owner controls, and it moves backups, updates and hardware failure onto the operator. Several of my products are self-hosted because the customers' constraints made that the better answer. For other workloads a managed service is the right call.
Backups and recovery
Every project documents what is backed up, where it goes and how it is restored, and the restore is tested. See DevOps.