I run a production AI app for €60 a month. Here is the actual bill

Description and use

In a small pet‑health AI app, inference costs only a few cents per heavy user per month; storage and database dominate. Smart choices—single multimodal calls, caching, per‑user counters, and a simple VPS stack—keep the bill €60–200/month.

Problem

How to keep a production AI pet‑health app running on a single VPS for €60–200/month while serving AI features

Outcome

Inference costs only a few cents per heavy user per month; storage and database are the main cost drivers. A simple VPS stack with caching and per‑user limits keeps the bill between €60–200/month for a small user base.

Workflow

• 1. Send audio once to a multimodal model for transcription and structured output
• 2. Apply rule prefilter, vector rank, then one model pass for recommendations
• 3. Cache recommendations for seven days
• 4. Use per‑user daily counters instead of global rate limits
• 5. Run NestJS, Postgres, pm2, nginx, Cloudflare on one VPS
• 6. Prune original images, re‑encode to WebP
• 7. Store confidence scores and require user confirmation before writing to record

Evidence

A very heavy user — thirty assistant messages a day plus a daily health check — costs a few cents a month in inference. Their storage and database footprint costs more than their AI does.

Source

Inference is a tiny fraction of the bill; storage, database, and caching dominate.

Source

We spent months worrying about the wrong line item.

Source