• I run 50+ websites
• MariaDB instances
• PostgreSQL instances
• Docker container
• Mbin, Nextcloud, GitLab, GitLab runners, gitea, bitcoind, fulcrum, grafana, prometheus, influxdb, Synapse, Angie, telegraf and various other services like fail2ban etc. etc.

All optimized for performance and fine tuned as well, eg. lets say you run mariadb vs how I run null

innodb_buffer_pool_size = 8G
innodb_flush_log_at_trx_commit = 2
innodb_log_file_size = 2G
innodb_log_buffer_size = 32M
innodb_max_dirty_pages_pct = 90
innodb_io_capacity=5000
innodb_io_capacity_max=20000
innodb_read_io_threads=8
innodb_write_io_threads=8
query_cache_type = 1
query_cache_limit = 2M
query_cache_min_res_unit = 2k
query_cache_size = 128M
tmp_table_size= 128M
max_heap_table_size= 128M

[mysqld]
max_connections = 200
character_set_server = utf8mb4
collation_server = utf8mb4_general_ci
transaction_isolation = READ-COMMITTED
binlog_format = ROW
innodb_file_per_table=1
# Increase open files based limits.conf value
open_files_limit=65535

Same idea for Postgresql.. You can run "postgres" or.. actually run postgresql in production correctly like:

shared_buffers = 6GB
work_mem = 20MB
maintenance_work_mem = 2GB
maintenance_io_concurrency = 200
max_worker_processes = 14 
max_parallel_workers_per_gather = 4
max_parallel_maintenance_workers = 4
max_parallel_workers = 12

synchronous_commit = off
commit_delay = 300

checkpoint_timeout = 30min
max_wal_size = 60GB
min_wal_size = 4GB