
howardchen.substack.com
June 16, 2026
12 min read
44/100
Summary
DeepSeek V4 Pro is available at 5% of the cost of Claude and offers a range of features including hash-anchored edits, a sticky prefix cache, and autonomous loops for production code. It has been used for various applications such as training dose-prediction models for radiotherapy and developing a financial research agent, with no associated charges.
Key Takeaways

Improving 15 LLMs at Coding in One Afternoon. Only the Harness Changed
Feb 12, 2026

The Harness Is the Thing
Aug 26, 2026

Why Software Factories Fail (or: harness engineering is not enough)
Jul 23, 2026

The agent harness belongs outside the sandbox
May 2, 2026

Claude Code sends 33k tokens before reading the prompt; OpenCode sends 7k
Jul 12, 2026