Real-World Case Studies
How OpenAI Deep Research, Claude Code, Perplexity, Cursor, and Devin work under the hood. Production architecture breakdowns with design decisions for interviews.
Last updated
Real-World Agentic Architectures
How five of the most impactful AI products actually work under the hood — with the architecture decisions and metrics you can quote in an interview.
OpenAI Deep Research, Claude Code, Perplexity, Cursor, and Devin look like five different products, but under the hood they reuse a small set of patterns: tiered model routing, execution isolation, action classification, a self-correction loop, and a human gate for risky actions. Learn the patterns, not the trivia — then you can reason about any agentic product an interviewer throws at you.
Below, each case study leads with the one architectural idea it made famous, shows how the pieces fit together, and ends with the line you can actually use in an interview. First, the lay of the land: