joel@ibm:~$ whoami

Joel Hanson

Software engineer at IBM Event Streams. Kafka, Kubernetes operators, and AI tooling. I write about what I build and learn.

~/pinned

Configuring Kafka Connector with Docker: A Step-by-Step Guide

12 October 2024 6 min

In this tutorial, we’ll walk through the process of setting up a Kafka connector using Docker and docker-compose.yml. We’ll focus on configuring a file connector, which is useful for reading data from files and writing data to files using Kafka.

Supercharging Your AI: Setting Up RAG with PostgreSQL and pgvector

30 September 2024 4 min

Learn how to implement a powerful Retrieval-Augmented Generation (RAG) system using PostgreSQL and pgvector. This comprehensive guide covers everything from setting up a custom PostgreSQL Docker image to creating a fully functional RAG query system with vector embeddings and language model inference.

#PostgreSql #PGVector #RAG #Vector Database

Convert Your Django DRF Project to MCP in 5 Minutes

3 August 2025 13 min

The Problem: When APIs Meet AI Assistants # A few weeks ago, I was experimenting with Model Context Protocol (MCP) for a Kafka integration project. The experience was eye-opening - being able to interact with complex systems through natural language felt like a glimpse into the future of development workflows.

#Django #MCP #AI #API

Setting Up a Kafka Cluster Without Zookeeper Using Docker

5 October 2024 4 min

Introduction # In this post, we will walk through the process of setting up an Apache Kafka cluster without using Zookeeper, leveraging Kafka’s KRaft mode for metadata management. Kafka no longer requires a Zookeeper instance, simplifying the cluster setup. We will use Docker to deploy this Kafka cluster with the latest version of Kafka.

list_topics.py python

1from mcp.server.fastmcp import Context, FastMCP23mcp = FastMCP("Kafka MCP Server", lifespan=kafka_lifespan)45@mcp.tool()6def kafka_list_topics(ctx: Context) -> str:7    """List all topics in the Kafka cluster"""8    manager = ctx.request_context.lifespan_context.kafka_manager9    if not manager:10        return "Error: Not connected. Use kafka_initialize_connection first."1112    try:··…

Building an MCP Server for Your Kafka Cluster

7 June 2025 5 min

A step‑by‑step guide to using FastMCP and the MCP protocol to expose Kafka operations (topic management, produce/consume, troubleshooting) as LLM‑accessible tools.

#Kafka #MCP #FastMCP #Python

~/posts

Wayfare: I Plan Trips More Than I Take Them

1 August 2026 6 min

I keep losing trip research across ChatGPT, Claude, and Cursor. So I built Wayfare: a travel bucket list with savings tracking, plus MCP so connected chatbots can use the same trip context.

#Wayfare #MCP #Travel #Side Project

MQSinkTask.java java

1} catch (final RetriableException rte) {2    if (firstFailureTime == null) {3        firstFailureTime = System.nanoTime();4    }56    final long elapsedMs =7        (System.nanoTime() - firstFailureTime) / 1_000_000L;8    if (elapsedMs >= errorRetry) {9        firstFailureTime = null;10        throw new ConnectException(11            "Retry timeout of " + errorRetry + "ms exceeded. Killing task.",12            rte);··…

The Connector That Kept Retrying and Never Said So

30 July 2026 3 min

A customer reported that their Kafka Connect MQ Sink connector looked completely healthy — no errors on the connector CR, no failed tasks — but no messages were reaching MQ. This had been going on for hours.

Aesthetic Habit Tracker: A Challenge Grid That Lives in Your Browser

7 June 2026 4 min

Most habit apps want an account, a subscription, and a notification every hour. I built a minimalist challenge tracker that stores everything locally, exports to PDF, and ships free on GitHub Pages.

#Habit Tracker #GitHub Pages #PWA #Next.js

From Prompt to Home Screen: Shipping Nursing Tracker with GitHub Pages

7 June 2026 6 min

My wife was losing track of feeds, so I built a one-tap nursing timer that grew into a pumping log, and shipped it for free on GitHub Pages with no database and no app store.

#GitHub Pages #PWA #Side Project #Web Development

Send Half the Bytes Over the Network: Cut Kafka Integer Payloads with Bijou64

6 June 2026 7 min

Every Kafka record with a Long value you produce sends 8 bytes over the wire, even when the value is 42. Bijou64 encodes integers in 1–3 bytes with drop-in serializers, cutting network transfer and replication traffic on integer-heavy topics by up to 50% or more.

#Kafka #Java #Performance #Serialization

Stream Wars: A Simple Game to Explain Kafka

19 December 2025 4 min

I built Stream Wars as a tiny tap game to demo how Kafka works, by turning every tap in the browser into a real Kafka event you can inspect.

#Kafka #WebSockets #Real-Time #Event Streaming

[all posts →]

~/series

Reading paths for Kafka Connect and MCP.

Kafka Connect

From a KRaft cluster to custom connectors, tombstones, tests, and streaming into Kafka.

7 posts

MCP

Expose Kafka, Django APIs, and REST APIs as tools for AI assistants via the Model Context Protocol.

3 posts

[all series →]

~/projects/platform

Kafka, MCP, connectors, and related open source work.

Apicurio Registry

Led Apicurio Registry V2→V3 for Event Streams; upstream HTTP MCP + OAuth forwarding is an open PR under review.

ContextLayer

Transform any REST API into an MCP server — connectors that make existing APIs usable by LLM tools.

Kafka MCP Server

Expose Kafka cluster operations as LLM-accessible tools via the Model Context Protocol.

bijou64

Shrink Kafka integer payloads with a compact encoding library for Java/Kafka apps.

Kafka Connector Template

Production-ready Kafka Connect template with Testcontainers integration tests.

Stream Wars

A real-time multiplayer tap battle that turns every click into a Kafka event you can inspect.

SSE Kafka Connector

Kafka Connect source that turns Server-Sent Events streams into Kafka topics — used in Event Streams demos.

Django DRF → MCP

Turn an existing Django REST Framework project into MCP tools for AI assistants in minutes.

~/projects/personal

Side apps and smaller tools.

Markdown2Medium

Convert Hugo-friendly Markdown into Medium-ready posts with a live preview and one-click copy.

Wayfare

Travel bucket list and savings tracker with MCP. Same trip context in ChatGPT, Claude, and Cursor.

Antarctic Iceberg Tracker

Real-time iceberg monitoring with NASA data, automated pipelines, and GitHub as a data platform.

Habit Tracker

Aesthetic challenge-grid habit tracker hosted on GitHub Pages.

Nursing Tracker

Home-screen PWA for nursing/feeding logs, built and shipped on GitHub Pages.

[all projects →]

~/discoveries

Short finds: snippets, demos, and link-outs.

[media] 2026-08-01

Wayfare: trip context over MCP and OAuth

Travel bucket list and savings tracker. Same trip data in Claude, Cursor, and ChatGPT, per user via OAuth.

Built partly to learn MCP OAuth and how to ship a secure, production-ready MCP server. Connect once, and each assistant only sees your trips and fund.

[media] 2026-06-07

Challenge-grid habit tracker, no account

A local-only challenge grid — tap a day, export PDF, ship on GitHub Pages.

Built for “Day 12 of 30” goals instead of calendar-month trackers. Everything stays in the browser.

[link] 2026-06-06

Shrink Kafka int payloads with bijou64

Variable-length unsigned 64-bit ints — small numbers stay small on the wire.

Drop-in Java serializers for Kafka so you can swap encoding without rewriting app logic.

[all discoveries →]

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