Things We Build and Learn
A collection of implementation notes, technical walkthroughs and lessons from working on real systems. Some articles cover current projects; others remain here as engineering archives.
Engineering notes ·
Building an Autonomous Website with vLLM, Hermes & Go
How we use vLLM, Hermes and a custom agent driver to autonomously research, maintain and administer SanJuanPuertoRico.org through MCP and Go.
Engineering notes ·
Your Test Harness Should Know When an MCP Tool Calls an LLM
MCP tools are dependencies of your tests. Disclosing LLM inference and external API calls helps you choose assertions, fixtures and verification checks.
Engineering notes ·
Agentic Lab Workflows with Janus, Hermes & Ollama
Build a custom assistant harness connecting Hermes and Ollama to FlaskTrack through MCP, with draft creation, human review and electronic signatures.
Engineering notes ·
Observing AI Workflows with Rust and Langfuse
Connect Rust AI applications to self-hosted Langfuse, reuse existing infrastructure, and keep observability optional and resilient.
Engineering notes ·
Lightweight Analytics for People & Agents
Use Nginx and GoAccess to reduce browser overhead, understand website and agent traffic, and provide useful context for AI-assisted business automations.
Engineering notes ·
Patch Ubuntu, Rust & Go After eMudhra
Update Ubuntu certificate stores, patch Rust TLS dependencies, rebuild Go applications, and verify remediation after the October 2026 eMudhra incident.
Engineering notes ·
Connecting Hermes, Rust & Thunderbird
Connect Hermes AI workflows to Thunderbird with a Rust native messaging bridge, SQLite queues, explicit approvals, and duplicate-send protection.
Engineering notes ·
Building an MCP agent and server in Rust
Archived tutorial on building an MCP server and agent in Rust, exposing tools, and connecting language model APIs.
Engineering notes ·
Building a web application with Rust
Archived Rust web application tutorial covering Tide, Askama, SQLx, and PostgreSQL. Historical examples from Santurce Software.
Engineering notes ·
Keeping websites small
Practical notes on smaller websites: reduce page weight, optimize images, and simplify frontend dependencies.
Engineering notes ·
Machine learning and San Juan traffic
An archived exploration of machine learning for traffic patterns and transportation in San Juan, Puerto Rico.
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