Loved the chat between @trq212 @_catwu @simonw at AI Eng summit. My top 13 takeaways from their session -> 1. Engineers should become better…

Loved the chat between @trq212 @_catwu @simonw at AI Eng summit. My top 13 takeaways from their session -> 1. Engineers should become better at product/business sense. 2. Don't worry about major rewrites anymore. 3. Claude Tag - Multiplayer by default. Proactive instead of rewrite. Lands 65% of PRs. Claude code is now reserved for the most complex tasks. 4. It’s interesting that they decided not to add sharing to Claude Code, decided that a new category like Claude Tag is better. 5. How to do prioritisation - Dogfood our internal products. Have an internal bar for retention and WAU of the feature before shipping it externally. Advantage is engineers know there is a clear metric they need to hit to ship. 6. Code review - have a GitHub code review bot. Code owners for that field manually need to approve complex PRs. Spent a lot of time CI/CD setup to build trust over a period of time. 7. Anthropic now has different system prompts for different models. Continuing to simplify system prompts as models are becoming better. For example, giving examples helps Fable less than Opus. Frontier models have 80% less tokens in their system prompts. 8. What was insane for me is that in the middle of the session, when Cat got feedback from Simon, she stopped and tagged Claude tag with that feature request (even when there are like 1000 people listening to them on stage). 9. Tool design is still an art instead of science. Keep cardinality low to make sure it’s easy for Claude to know what to call when. 10. Safety and security - Almost everyone in Anthropic uses Auto mode. They have done an insane number of red teaming and evals to tune the Sonnet classifier to ensure it’s “safe”. They have been using it within Anthropic since January to make it strong. Claude tag also internally uses auto mode and it’s a great example of why build vs buy for a “slack bot” should lean towards buy, there are a lot of edge cases to manage. 11. What they want it to do better - Better design and taste (this is shocking because anthropics models are so much better at this than most other models already). Also better at science. 12. Claude tag works when most of the channels are public. It doesn’t search private channels, only public channels. 13. They use workflows even for non coding tasks like travel planning, etc.

Source: Swyx (X) | 2026-07-01