Summary of "We’ve lost the Tech"

Summary of “We’ve lost the Tech” Video

The video provides a critical technical analysis and engineering review of Anthropic’s Claude Code TUI (Terminal User Interface), focusing on its architectural and performance choices.

Key Technological Concepts & Product Features

Claude Code TUI Overview

Claude Code’s UI is described as a complex TUI that behaves more like a small game engine rather than a simple terminal interface. It renders text and UI elements using a scene graph constructed from React, which is then rasterized and diffed each frame to generate ANSI escape codes for terminal display.

Rendering Pipeline

The rendering pipeline involves:

React building a scene graph
Laying out UI elements
Rasterizing in 2D
Diffing against the previous frame
Generating ANSI strings for terminal rendering

ANSI codes control text color, cursor position, and screen clearing.

Performance Constraints

The system targets a 16 ms frame budget (about 60 FPS), with 11 ms spent just on React layout for roughly 2400 “pixels” (characters). This is considered excessive given the nature of the UI.

Engineering Critique

The demand for 60 FPS in a TUI interacting with a slow backend (a language model with seconds-to-minutes response times) is seen as a fundamental engineering misstep.
Using React, a web UI framework designed for complex browser interfaces, is criticized as an inappropriate and legacy-driven choice for a terminal UI, leading to unnecessary complexity and performance overhead.
Maintaining a full scene graph and diffing every frame is likened to game engine design, which is overkill for a mostly static, text-based interface with limited interactivity.

Alternative Approach Suggested

A more straightforward, event-driven rendering model that updates the UI only on input, output, or minor UI state changes (e.g., throbbing indicator) would be more efficient.
No continuous frame loop or 60 FPS requirement is necessary because user input and output from the language model are inherently slow and sparse.
Layered rendering with scrollback history and minimal interactive elements can be handled without React or a scene graph, using immediate mode or simple diffing strategies.

Performance Testing

The presenter built a custom rendering test outside React, simulating high-frequency updates with thousands of small boxes rendered per second on a modern GPU-accelerated terminal. The test showed that terminals can render far faster than 60 FPS, implying the bottleneck is in React or architectural choices, not the terminal or JavaScript.

Engineering Management Insights

The insistence on 60 FPS and React-driven scene graph diffing is seen as a failure of engineering leadership and management, reflecting poor decision-making and legacy constraints rather than technical necessity.
The video stresses the importance of stepping back to question initial design decisions rather than blindly solving immediate technical challenges.
It is suggested that Anthropic should consider hiring developers with experience outside web UI frameworks—such as game or tools developers—to rethink the architecture.

Broader Lessons

Using the “most comfortable tool” (React, TypeScript) rather than the best tool for the job can lead to inefficient, overcomplicated systems.
LLM-generated code or hype around AI-driven development does not guarantee good engineering decisions or outcomes.
Hard engineering skills and critical thinking remain essential to build performant, maintainable software.

Guides, Tutorials, and Reviews

The video includes a mini performance test tutorial demonstrating how to benchmark terminal rendering speeds using JavaScript and modern terminals.
It provides a conceptual guide on how TUIs should be architected for efficiency, advocating event-driven rendering rather than continuous frame loops.
It reviews the Claude Code TUI’s architectural choices and provides a detailed critique of their React-based rendering pipeline.

Main Speakers / Sources

The primary speaker is an experienced engineer and engineering manager (unnamed in the transcript) providing commentary and analysis.
References and quotes are made to:
- Tyreek (Twitter user who made the original tweet about Claude Code’s React rendering performance).
- Will McGugan, a respected engineer with experience in TUIs and game development, whose insights on the complexity of TUIs and architectural choices are cited.

Overall Summary

The video is a deep dive into the engineering trade-offs and pitfalls in the design of Anthropic’s Claude Code TUI. It highlights how legacy decisions and inappropriate technology choices (React for terminal UI) have led to unnecessary complexity and performance issues. The video advocates for simpler, more appropriate engineering approaches and better management oversight.