System Design
System design stories and patterns focused on latency, scalability, and reliability, with concrete examples from booking engines, in-memory indexing, and Elixir/BEAM architectures.
Can a Couple of Rows in Postgres Really Cost This Much?
I got tired of paying for managed PostgreSQL, moved my projects onto Hetzner, and added a LiveView dashboard to Supavisor. A practical guide to Ecto, pooling, SSH, deployment, and migrations.
I Built a Vector Engine in Rust. Then I Started Wondering Where Elixir Had Gone.
Why I moved Vettore's canonical records out of Rust and into ETS, what it changed for HNSW recovery, and where binary vector search loses accuracy.
WhatsApp Had Acknowledged the Message. My Client Kept Waiting.
An actual ACK regression, two WhatsApp addressing identities, a priority queue built with Erlang, and the limits of backpressure in a GenServer.
I Wanted an AI-Managed Blog. I Ended Up Using Git as the Database.
Why ExBlog keeps articles in Git and serves them from ETS, and how it handles atomic index replacement and concurrent readers in Phoenix.
I Taught My Agents to Remember. The Hard Part Was Keeping Deleted Memories from Coming Back.
Tombstones, append-only memories, physical deletion and an erasure-fence regression test for concurrent writes in Spectre Mnemonic.
Why my Phoenix node “finished loading” but RAM never came back
A hands-on story about tracking down stubborn RAM usage in a Phoenix node after a heavy data load.
How to Leverage Git Trees for Parallel Agent Workflows
Learn how to leverage Git trees to let multiple agents work on the same project in parallel using branches and worktrees for clean, conflict-free workflows.
Why You Might Not Need A Vector Database When PostgreSQL Can Power Your RAG
Want to build RAG without dragging a new vector database into your stack? In this guide we walk through how to turn plain old PostgreSQL into a serious RAG backend.
How I Ended Up Pricing Boats With Bitmaps And ETS
I wanted a booking search that felt instant, not “wait while I join five tables and cry”, so I ended up encoding availability and prices into tiny bitmaps and shoving them into ETS. Here’s how and why that works.