What I Found Interesting in Claude Code's Source
A breakdown of the most interesting engineering patterns in Claude Code's leaked source code: composable system prompts, runtime instruction injection, context compression, forking, prompt caching architecture, and more.
The Spec Can Come Later - The Phoenix Architecture
When I say things like "delete the code, keep the spec," many people seem to interpret that as a rule: write the specification first, and only then are you a…
The Spec Can Come Later - The Phoenix Architecture
When I say things like "delete the code, keep the spec," many people seem to interpret that as a rule: write the specification first, and only then are you a…
Diving into Claude Code's Source Code Leak
Engineer’s Codex is a publication about real-world software engineering.
Sourcegraph — Code Understanding, Oversight and Evolution
Give humans and agents complete context to understand, oversee, and evolve the world's largest, most complex codebases.
Entire Claude Code CLI source code leaks thanks to exposed map file
512,000 lines of code that competitors and hobbyists will be studying for weeks.
Software 4.0: When Code Stops Being an Artifact
The next step in Andrej Karpathy’s Software evolution: what happens when code is generated at runtime, executed once, and never saved…
Specs 2
Specs 2 is an ecosystem for specs driven component development. Via the plugin, turn a selected Figma component or component set into a compact, complete, schema-valid specification — computed directly from the file, not inferred from a screenshot. From the command line, generate specs from an en...
When Science Goes Agentic
In a couple of years, we will inspect AI-generated source code about as often as we inspect the assembly output of a compiler. Which is to say, far less often—outside of high-stakes and adversarial settings. The trajectory is clear: vibe coding is not a fad but a transition, a stepping stone. Debugging AI-generated code will shrink dramatically for a lot of everyday software—not because the code will be flawless, but because the feedback loops between generation, testing, and correction will tighten until human inspection becomes the bottleneck rather than the safeguard. In this respect, requiring the co-generation, with code, of mechanically verifiable formal attestations can also improve the process.
crawshaw - 2026-05-07
The industry-established code review process, review-then-commit, was a straightforward mechanism that allowed a relatively low-trust group of engineers to collaborate. It appears to have been initially developed for the Apache server OSS project in the 90s, corporatized by Google in the early 2000s, and popularized throughout the industry by several means, most notable of which was the GitHub PR.
Emelia (@thisismissem.social)
Their code was messy to say the least & did things that simply made no sense to do if you want to preserve interoperability. It looked more vibe coded than written by a competent developer. A few of us tried to nudge them in the right direction, and then they went closed source.
Priivacy-ai/spec-kitty
Spec-Driven Development for serious software developers. Spec Coding with with Claude, Cursor, Gemini, Codex. Kanban dashboard, git worktrees, auto-merge and more.
