The art of simplicity

As developer or architect, you make a lot of design decisions every day. You picked Redis for caching, or REST over GraphQL, ... . You move on after your decision was made, but in the back of your head a voice keeps asking "should I bother a colleague and ask for a second opinion?" , "what if I forgot something?" , "is this really the right choice?" The GitHub Copilot app can help you out with a (new) slash command: /spar . What /spar actually does /spar switches Copilot from "help me build this" to "convince me this is a bad idea." Instead of accepting your plan and generating code, it starts poking at your assumptions, asks about edge cases, and points out tradeoffs you may have skipped past. Remark: this is different from /plan , which helps you break a task down. /spar assumes you already have a plan and wants to stress-test it before you commit. How to use it Type /spar in the chat composer, followed by whatever...

Microsoft just released The Story of VS Code , an official documentary directed by Stefan Kingham that traces the editor's ten-year journey; from a small team in Zurich building a browser-based editor called Monaco, to the tool most of us now open dozens of times a day. Watching it made me think back on my own relationship with VS Code, which turns out to be more of a slow conversion than a sudden switch. Two editors, one workflow For most of my career I've been a Visual Studio guy. Full IDE, integrated debugger, the whole .NET toolchain in one window. That didn't change overnight. What did change is that VS Code quietly became my default for anything web-related — a bit of JavaScript here, a config file there, a quick edit to a YAML pipeline. For years I ran both editors side by side, each with its own job. Visual Studio for "real" application code, VS Code for everything lighter and faster. The extensions ecosystem got me curious I always liked what t...

In my previous post , I covered what Copilot Spaces are and how to set one up. Spaces live on github.com by default, but you don't have to leave your editor to use one. The GitHub MCP server exposes your Spaces as tools, so you can pull that curated context straight into VS Code. Prerequisites You'll need the remote GitHub MCP server configured for VS Code, and the copilot_spaces toolset explicitly enabled. It's not part of the default toolset. The easiest way is to install the GitHub extension in VS Code. This will also add the GitHub MCP server. But as I mentioned above, you will not find the copilot_spaces toolset out-of-the-box. You need to open up the MCP configuration and explicitly add it there. Add this to your .vscode/mcp.json (or your global MCP configuration): { "servers": { "github": { "type": "http", "url": "https://api.githubcopilot.com/mcp/", "headers"...

A lot of developers are using GitHub Copilot as their day-to-day agent harness. But most of them seem to be unaware that with a GitHub Copilot license comes more than a CLI and Visual Studio (Code) plugins. One thing you get access to are GitHub Copilot Spaces. GitHub Copilot what? Let me first explain what Spaces are and why they are useful. Why GitHub Copilot Spaces? If you've used Copilot Chat for a while, you recognize the pattern: you paste in the same background information for the third time this week. The same coding conventions, the same architecture decisions, the same "no, we don't use that library anymore" context. Close the conversation, and Copilot forgets all of it. Remark: Part of the answer can be found in building up your CONTEXT.md file and using the GitHub Memory feature but it’s not always the right solution. That's because source code lives in your repositories, requirements live in issues and pull requests, and team conventions o...

If you've built anything with the Microsoft Agent Framework (MAF), you'll notice that your tool calls can fill up the context window quite fast. A function that returns a list of 50 orders as JSON easily costs you a few hundred tokens on braces, quotes and repeated field names alone. That cost hits you twice: once on the way into the model as tool output, and again on every subsequent turn where that history gets replayed. That's where TOON (Token-Oriented Object Notation) comes in. Let's explore this. What TOON actually is TOON is a line-oriented, indentation-based encoding of the same data model JSON uses. It borrows YAML's indentation for nested objects and CSV's tabular layout for arrays of uniform objects. The trick is in that last part: if you have a list of objects that all share the same fields, TOON declares the field list once and then just streams the values, row by row, instead of repeating every key for every item. Take a small object like t...

There's a version of leadership that looks busy, looks needed, and looks like it's working but turns out to be the least effective version there is. This summer I read Bob Chapman's Everybody Matters , and one distinction from the book kept coming back to me weeks after I'd finished it: firefighting versus firelighting, as two fundamentally different modes of leadership.   Chapman's point is simple to state and harder to live by. A firefighting leader spends their energy reacting: jumping from one problem to the next, stepping in to rescue a team the moment something goes wrong. A firelighting leader does the opposite. They don't chase problems. They ignite something in people, so the problems get solved without the leader showing up with the extinguisher every time. In the book, the differences are listed like this: Firefighting: Reactive by nature . You wait for the smoke before you act. The leader becomes the bottleneck. Nothing moves unti...