https://newsletters.rafacastello.com/ A daily themed digest of design, branding, tech, and culture newsletters, Substacks, and top Google News stories — prepared every weekday morning for Rafa Castello. en-us rafacastello@gmail.com (Rafa Castello) rafacastello@gmail.com (Rafa Castello) Wed, 29 Apr 2026 20:25:35 +0000 https://newsletters.rafacastello.com/2026-04-29.html https://newsletters.rafacastello.com/2026-04-29.html Wed, 29 Apr 2026 12:00:00 +0000 Ana Andjelic’s latest Sociology of Business arrives timed to Rick Rubin’s Rock and Roll Hall of Fame induction this November — but uses it as the springboard for something sharper. Taste is everywhere on Substack. So is The Devil Wears Prada 2. The movie about the foremost taste-making industry in the world almost certainly measured its promotional campaign in impressions, reach, and views. Andjelic’s point: impressions are evidence that people scrolled past you. They are not cultural relevance. https://newsletters.rafacastello.com/2026-04-28.html https://newsletters.rafacastello.com/2026-04-28.html Tue, 28 Apr 2026 12:00:00 +0000 Ky Decker’s essay in today’s Sidebar asks the question that a growing cohort of designers and engineers are whispering in DMs but not saying in standups: Do I belong in tech anymore? The subtitle frames the triptych: quitting, the spread of AI, and the loss of an ideal. It lands differently when paired with the week’s other data point about what “belonging in tech” now looks like from the inside. https://newsletters.rafacastello.com/2026-04-27.html https://newsletters.rafacastello.com/2026-04-27.html Mon, 27 Apr 2026 12:00:00 +0000 Ana Andjelic’s “What Rick Rubin and Duomo Have in Common” in this week’s Sociology of Business opens a provocation that has been quietly spreading across the strategy Substacks: taste, not reach, is the durable competitive advantage. Rick Rubin gets inducted into the Rock & Roll Hall of Fame this November. His most important line, delivered to Anderson Cooper: he trusts his taste completely. https://newsletters.rafacastello.com/2026-04-24.html https://newsletters.rafacastello.com/2026-04-24.html Fri, 24 Apr 2026 12:00:00 +0000 Matt Webb published a compelling argument for headless everything — personal AI agents should interact with services through CLIs and APIs, not by clicking around a GUI with a bot-controlled mouse. His reasoning is practical: CLIs inherit Unix philosophy, designed for interoperability. Traditional apps force users through rigid “user journeys,” but real people multitask across services. Headless access is quicker, more dependable, and dramatically more composable. https://newsletters.rafacastello.com/2026-04-23.html https://newsletters.rafacastello.com/2026-04-23.html Thu, 23 Apr 2026 12:00:00 +0000 Anthropic launched Claude Design this week, and the design community is processing what it means. Describe what you need, Claude builds a first version. Refine through conversation, inline comments, or direct edits. If your team has a design system, Claude reads it and applies your tokens, components, and brand automatically. The handoff to Claude Code is built in — straight from design to production. https://newsletters.rafacastello.com/2026-04-22.html https://newsletters.rafacastello.com/2026-04-22.html Wed, 22 Apr 2026 12:00:00 +0000 Three separate newsletters converged on the same story this week: the economic foundations of AI services are cracking. The era of flat-rate subscriptions that let users burn $8–$13 worth of compute for every $1 of subscription revenue is coming to an abrupt end. https://newsletters.rafacastello.com/2026-04-21.html https://newsletters.rafacastello.com/2026-04-21.html Tue, 21 Apr 2026 12:00:00 +0000 Kai Brach's editorial in Dense Discovery #385 is the sharpest thing written about tech this week — and it has nothing to do with products or funding rounds. It's about the growing rift between what we value and how we actually live.