Engineering Reads — Week of 2026-04-02 to 2026-04-10#

Week in Review#

This week’s reading reflects a fundamental inflection point: raw LLM intelligence is no longer the bottleneck in software development. Instead, the industry is pivoting toward the hard systems engineering required to constrain probabilistic models—whether through strict data ledgers, living specifications, or formal verification harnesses. The dominant debate centers on how we preserve architectural taste, mechanical sympathy, and system ethics as the mechanical act of writing code becomes increasingly commoditized.

Simon Willison — Week of 2026-05-08 to 2026-05-15#

Highlight of the Week#

The standout development this week is Simon’s rapid adaptation to the latest frontier model capabilities, most notably releasing llm 0.32a2 to expose and visualize the new interleaved reasoning tokens of GPT-5 class models directly in the terminal. This perfectly pairs with his hands-on explorations of embedding LLM calls deeply into developer workflows, such as executing prompts via script shebangs and leveraging models to output rich HTML rather than just Markdown.

Engineering Reads — 2026-04-07#

The Big Idea#

The defining engineering challenge of our time isn’t just writing logic—it’s managing the friction between abstraction layers. Whether you are evolving storage interfaces to reduce data friction, stripping away software abstractions to respect hardware cache lines, or using standardized protocols to finally introspect opaque build systems, effective systems design requires knowing exactly when to hide the underlying machinery and when to expose it.

Simon Willison — 2026-05-12#

Highlight#

The standout update today is the alpha release of llm 0.32a2, which adapts to OpenAI’s new endpoints to expose interleaved reasoning across tool calls for GPT-5 class models. It’s a great example of Simon quickly evolving his CLI tools to make the latest LLM reasoning capabilities highly visible and practical for developers.

Posts#

llm 0.32a2 · Source Simon dropped a crucial update to his llm CLI to support the latest reasoning-capable OpenAI models (like the GPT-5 class), which now use a different endpoint rather than /v1/chat/completions. This shift enables interleaved reasoning across tool calls, and the CLI now natively displays these summarized reasoning tokens in a distinct color directly in the terminal. For those who prefer a cleaner output, you can easily suppress the reasoning steps using the new -R or --hide-reasoning flags.