Newsletter #67 – Algorithms to Live By, New podcast – TypeScript MCP, and the Future of AI Agents

DanielNovember 13, 2025November 13, 2025

Hey! It's Daniel here, author of 📘 Building Al Agents with LangGraph js and 📕 LangChain for JavaScript Developers.

I hope your November has started well! Mine was tiring (what else is new?) but I had a good time with family and some Claude AI side project work.

Anyways, let's learn:

• 🎙 A couple of days ago, I interviewed Paolo Ricciuti, senior software developer at Mainmatter. Paolo is a core contributor to Svelte.js and also a maintainer of the TypeScript MCP library. We touched on many things, but a really interesting topic was what the Svelte team is doing with its MCP server to upgrade code to new versions. Instead of putting the code as training data, they are passing the rules to the LLM on how to upgrade the code.
• 🎬 Over the weekend, I had time to listen to this great video with Aaron Francis on the best practices for making excellent screencasts and technical videos. Last year, Aaron produced over 250 videos, and he explains in detail the logic and process behind them.
• 🤓 A book I’ve recently enjoyed is Algorithms to Live By: The Computer Science of Human Decisions, a very nerdy and useful exploration of how mathematical algorithms can be applied to our everyday lives.
• 🎯 And speaking of using algorithms in real life, I particularly liked the Secretary Dilemma. You meet candidates one by one and must pick the best without going back. Best simple rule: use the first 37% to learn what's good, then pick the next candidate who’s better than all you’ve seen. It’s great for picking the perfect job, apartment, or any solution when you don’t know the best possible outcome.
• 📡 Mastra AI — the TypeScript Agent Framework — just raised $13M USD. And this makes me very happy! The JavaScript AI ecosystem keeps growing and improving, and it reminds me of a tweet I once read that said something like, “Python is for training AI models, while JavaScript is for building with them.” I couldn’t agree more!
• 🎧 Btw, I interviewed Sam Bhagwat from Mastra AI some time ago. You can watch the interview below. Sam was also the founder of Gatsby.js, so he definitely knows what he’s doing.
• 📖 And if you want to get a deeper look at what the guys from Mastra AI are doing, you can request a free physical copy of their book Principles of Building AI Agents. Great stuff!
• 🔎 When someone buys my book and I see an email like name@company.com, I always check the company out. And this is how I discovered Parallaxis AI. They have some really good content on their blog and YouTube. I particularly liked this short episode on Metrics of Models.
• 💬 I’ve realised that the culture in Eastern Europe is much less forgiving of failure than in the U.S. Experiencing a professional failure is often seen as shameful. People don’t talk about their failures for fear of appearing weak. We can thank the legacy of communism for some of that mindset. There are fewer entrepreneurs since no one wants to be the one who tried and failed, given the harsher judgment by those who remained in line.
• 🧰 Idea: LLMs, with their natural language processing capabilities, will become the UI. For example, you won’t need to learn Excel’s clunky interface or functions, as the LLM layer will understand commands like: “Give me the average of the top 50% of values from the salary column.” And this is where tools such as LangChain.js and LangGraph.js can help a lot!
• 🇪🇸 Continuing our Spanish adventures, we took a 3-day trip to Nerja. Just check out this picture! I'm a bad photographer, but when the landscape and light are so beautiful, even I can take decent pictures.

And with that, we finish this edition of the JS-Craft newsletter! Be kind, keep coding, and keep learning! See you the next time!