Self-Hosted AI Inference Cluster

Jun 1, 2025 · 2 min read

What this proves: AI — I build and operate AI infrastructure right now: dual 3090s serving Qwen 3.6 35B to real workflows, zero cloud dependency.

This was the v1 single-box build. The current state is a three-server high-availability cluster with a custom routing plane — Highly Available AI Inference Cluster.

Overview

Running local LLMs isn’t a hobby — it’s a production system. This cluster powers everything from agentic coding workflows to personal AI assistance, running entirely on hardware I own with zero cloud dependency.

The core setup: dual NVIDIA RTX 3090s (48GB VRAM combined) running vLLM with tensor parallelism to serve Qwen 3.6 35B. 100K context window, 8 concurrent sequences, and the kind of throughput that actually makes local models usable for real work.

Hardware

  • GPU: 2x NVIDIA RTX 3090 (24GB VRAM each, 48GB combined via NVLink)
  • CPU: AMD Ryzen 9 5950X (16 cores)
  • RAM: 128GB DDR4
  • Storage: NVMe for model weights and cache

Software Stack

  • Inference: vLLM with tensor parallelism
  • Model: Qwen 3.6 35B (quantized)
  • Orchestration: Docker containers
  • API: OpenAI-compatible endpoint
  • Context: 100K token context window

What It Powers

  • Agentic coding workflows (this conversation, for example)
  • Code review and analysis
  • Research and documentation assistance
  • Personal AI tasks across the household
  • Model evaluation and benchmarking

Why Self-Hosted

Privacy, cost, and control. Every API call to a cloud LLM is a data leak waiting to happen. Every token costs money. Every rate limit is a deadline on your productivity. Self-hosted means your AI works when you need it, handles whatever you throw at it, and never charges per token.

The initial hardware investment pays for itself in a few months compared to equivalent cloud API usage. After that, it’s just electricity.

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Derek Armstrong - Payments Engineer · AI · Infrastructure
Authors
Payments Engineer · AI · Infrastructure
I’m a payments & POS engineer who knows the whole stack, from CPU to customer support, and I bring AI into the toolchain end to end: using, building, and maintaining it in production. 12+ years in production payment systems, running on the quiet infrastructure that has to work at 3am whether I’m awake or not.