The problem
At a billion keys, you're not paying for a database. You're paying for RAM.
Redis and other in-memory stores keep every value in DRAM — hot or cold. Cloud RAM costs 15–20× more per gigabyte than NVMe SSD, so the bigger your dataset grows, the more you pay simply to hold it in memory. That's a bill that scales with your data, not your revenue.
In-memory (Redis)
$3,000–5,000
/ month · ~250 GB DRAM
- Every value pinned in memory, hot or cold
- P99 spikes when AOF rewrite runs
- Cost grows linearly with dataset size
≈ 10× lower
VeltrixDB on NVMe
$300–500
/ month · ~160 GB NVMe
- Values on NVMe, only pointers in DRAM
- Flat P99 — GC never blocks reads
- Fixed cluster pricing, no per-op meter
Illustrative — 1 billion keys × 128-byte values, GCP list pricing. Your mileage will vary; the ratio won't.