The Daily Index — Wednesday, March 25, 2026 · TLDR Index

PROGRAMMING, DESIGN & DATA SCIENCE

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WHAT WE WISH WE KNEW ABOUT BUILDING AI AGENTS

The capabilities of agents are unquestionably valuable, but sometimes an MCP server is a better fit. A harness is not a moat - context is your advantage. Set up observability and evaluation from day one, as understanding user experience is critical to building a successful agent. It doesn't matter how 'cool' your capabilities are, as solving customer problems is the goal. Building an agent is a product engineering problem that requires talking to users, shipping features they want, and iteration.

newsletter.posthog.com · 9 min

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MY PRODIGAL BRAINCHILD

Meta has decided to shut down its Metaverse project, which the company reportedly spent $80 billion on. The company's vision of people wearing devices on their faces all the time is unlikely to be realized. People care too much about what they look like, and there is too much social stigma against being recorded without permission. There are already hundreds of millions of people in metaverses that don't require a headset to access.

nealstephenson.substack.com · 12 min

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AGENCY

Agency is the ability to hold the entire development loop in your head and act on it. A high-agency person can move through the whole sequence without waiting for someone else to hand them the next step. Agency is what you call it when one person can cover the full distance. What matters is that the whole thing exists in a user's hands, and that it was driven there quickly by one person's judgment.

links.tldrnewsletter.com · 11 min

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hands-on Microsoft Build 2026, June 2-3. Learn more.

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fandf.co

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META EXECUTIVE WILL SPEARHEAD PUSH TO GET EMPLOYEES USING MORE AI

Andrew Bosworth will oversee Meta's 'AI For Work' initiative to help drive AI adoption across the company's 78,000-person workforce.

links.tldrnewsletter.com · 3 min

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CHOOSE BORING TECHNOLOGY AND INNOVATIVE PRACTICES

Be conservative in the software you use, but be freely innovative in how you use it.

buttondown.com · 2 min

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ARM RELEASES FIRST IN-HOUSE CHIP, WITH META AS DEBUT CUSTOMER

It is unknown what the terms of agreement are, but if Arm gets even 5% of Meta's up to $135 billion of capital expenditures slated for this year, it will be a game-changer for its top line.

cnbc.com · 8 min

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THE CASE FOR WORRYING ABOUT AI-SPECIFIC COGNITIVE DEBT

AI could create a shortage of engineers who can possibly understand codebases.

natemeyvis.com · 3 min

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OSSATURE

Ossature is an open-source harness for spec-driven code generation.

ossature.dev · 11 min