David Bernstein

Design patterns aren’t solutions. They’re signals. Signals that reveal the forces inside a problem. If the force isn’t there → the pattern is wrong. New video: Patterns Aren’t Solutions (and Never Were) youtube.com/watch?v=ncUrf-…

Most developers think testability is about tests. It’s actually about design. When tests are painful → your design is telling you something. New video: Testability Is the Ultimate Code Smell Detector youtube.com/watch?v=2IBN03…

Most rigid systems aren’t complex. If construction and usage live in the same function, every new requirement edits that crossroads. Factories centralize identity. Create. Connect. Return. New video: Where Should Decisions Live in Code? youtube.com/watch?v=H_ueru…

5 optional features. 32 subclasses. That’s not bad design. That’s math. Variation belongs in data — not types. New video: Class Explosion (and how to stop it) youtube.com/watch?v=H_ueru…

New blog post: AI Doesn’t Replace Design Thinking — It Amplifies It - passprog.com/ai-doesnt-repl…

This line tells me everything I need to know about the system: order.customer.account.credit_card.charge() Senior developers: this one’s for you. youtube.com/watch?v=dFt_KV…

AI can write working code all day. Only you can tell if it’s any good. youtube.com/watch?v=aKXSfg…

Decorator and Chain of Responsibility look the same in UML — but they solve completely different problems. youtube.com/watch?v=ZhE7Db… Watch where the decision lives. That’s the pattern.

Most developers design too early or too late. This one question tells you when your design is actually ready. youtube.com/watch?v=dMM6Ma…

New blog post: Assertive Code Has Agency, Inquisitive Code Does Not - passprog.com/assertive-code…

If/else isn’t the real problem—your design shape is. Move selection into a factory and compose behavior as a pipeline (Decorator) to stop class explosion. youtube.com/watch?v=ZPcgaZ…

Patterns add freedom. Factories restore coherence. That’s why flexible systems still need constraints. youtube.com/watch?v=vDFEMl…

Dependency injection isn’t about frameworks. It’s about creating seams so code can change safely. youtube.com/watch?v=PuMpRw…

Agile development isn't 'shoot from the hip.' youtube.com/shorts/R2Q1ejP…

AI lets us refactor in minutes what used to take hours, but does it hold up? In this week’s video, I walk through the missing step senior developers use—before choosing patterns or restructuring code—and how AI can help if you ask the right questions. youtube.com/watch?v=VrmjP4…

New blog post: AI-Driven Design Thinking: Why Prompting isn’t Enough - passprog.com/ai-driven-desi…

Most messy code isn’t a coding problem. It’s a planning problem. Outside-in thinking before implementation changes everything. Claude’s Planning Mode makes this shift practical. youtube.com/watch?v=VqzsOb…

The CLI isn’t a tool. It’s a thinking space. Claude on the command line = design → clarity → refactoring → clean code. New video: youtube.com/watch?v=EduaKM…