Jon Karrer

Journal

I like to journal while coding. It helps organize ideas and keep track of progress. Also a great tool for remembering context when switching between projects. Here is a collection of some of those entries.

Entries

Image Classifier

Training an image classifier in Rust using tch-rs and transfer learning on top of a pre-trained ResNet18.

Language Classifier

Rolling a custom transformer-based NLP classifier in Rust with the Burn framework for the US patent phrase-matching task.

Patent Classifier

Preparing, tokenizing, and batching patent phrase-matching data for a Rust-built transformer classifier with padding masks and embeddings.

Raspberry Pi DNS

Turning a Raspberry Pi into a LAN-wide DNS server and ad blocker using Pi-hole inside Docker.

Shuttle Portfolio

Notes on moving the portfolio site to Shuttle with a markdown-powered journal page backed by Turso.

SQLx for SQLite

Using SQLx in Rust to run SQLite migrations, manage a connection pool, and wire up repository traits.

Titanic Binary Classification

Walkthrough of building a Rust neural network from scratch to predict Titanic survival and iterating on its hyperparameters.

Alpaca Rust SDK

Designing an open-source Rust SDK for the Alpaca trading API using a Serde-backed builder pattern.

AWS Certificate Manager

Step-by-step guide to serving an ECS service over HTTPS with an ALB and an ACM certificate.

AWS CLI Auth

Installing the AWS CLI on macOS and configuring IAM credentials to authenticate against AWS services.

AWS Elastic Container Registry

CLI reference for creating, pushing to, pulling from, and deleting Elastic Container Registry repositories.

AWS Elastic Container Service

Walkthrough for deploying a Docker image from ECR to a Fargate ECS cluster via the console and CLI.

Clap CLI Tool

Building a small Clap-based CLI in Rust for managing journal entries in a Turso SQLite database.

Claude Prompting Guide

Anthropic's tips for effective prompting, with concrete before-and-after examples for common writing and analysis tasks.

CSS SVGs Basics

Reference of the seven basic SVG shapes and the attributes that control their geometry and styling.

Daily Linear Classifier

Running thirteen hyperparameter experiments trying to train a baseline linear classifier to predict next-day stock direction.

Digit Classifier

Building a baseline MNIST digit classifier in Rust using Candle and tensor-averaged "ideal" images before moving to SGD.

Docker Basics

The minimum commands to write a Dockerfile, build an image, run a container, and clean up after it.

Docker Vite

Short recipe for containerizing a Vite app with a multi-stage Dockerfile and serving the build via nginx.

HTTPS Nginx Certbot

Setting up Nginx as a reverse proxy with Let's Encrypt certificates via Certbot, including a Docker Compose variant.

Algo Trading Bot

Overview of building a Rust-based stock trading bot that ingests live market data and executes bracket orders.

© 2026 Jon Karrer