I am running top-1000 site in one of EU countries on one 4 core machine with 20-30% load. Around 1000 http/https reqs/s. Most of those requests do couple of postgres reqs (read and write) and couple of redis reqs.

Elasticsearch - for searching/recommendations

Redis - hot data (certain data is only kept in redis)

Postgres - for the rest of data

Clickhouse - analytics

Most of the system is written in Go. Whole system was tuned for performance from day one. As to latency, data from the last 21 million requests today:

p99: 17.37 ms

p95: 6.86 ms

avg: 2.37 ms