Weave

Weave (W25) helps engineering teams understand whether their AI coding tools are actually making them more productive. Its models measure the work humans and agents produce and compare that output with AI spending. The company recently raised a $13.5M Series A led by Standard Capital and launched Weave Router, which selects models for different coding tasks. In this fireside, @WorkWeave co-founders @adambcohen93 and @AndrewChurchiII join YC's @snowmaker to share how the company evolved alongside the rapid rise of AI coding, from measuring the impact of tools like Cursor to helping teams build software factories that can work autonomously. They explain how the best engineering teams are learning to measure the real output of their agents, spread the habits of their strongest AI users, and optimize for a future where much more software is written without a human at the keyboard. 00:00 — Optimizing AI Coding With Weave 04:02 — Getting More From Your AI Budget 08:39 — Measuring Work Beyond Lines of Code 12:30 — From AI Adoption to Optimization 16:47 — Measuring AI ROI and Coaching Engineers 20:16 — Building Software Factories 25:38 — The Future of Model Routing

I got flown out to SF for tech week! I want to meet as many people as possible in the next 72 hours. Thank you to Weave for making this happen.

How does a company allocate token budget to it's employees? One interesting analogy is to how multi-strat hedge funds allocate balance sheet amongst different pods. I think there are multiple startups to be built in this space. Let me know if you're building something here.

SF Tech Week FOMO? We’re flying out creators + builders to SF TONIGHT. Flights + hotel covered. Build with us, explore Tech Week, & meet great people. First one out: @jackprice. Good at what you do? DM me or @adambcohen93

pov: checking the bill after giving our agent the DoorDash CLI and telling it to “handle lunch”

Weave is launching the number 1 prompt router in the world. It enables you to get 70% more efficient use of your tokens. We analyzed millions of prompts and found that the vast majority don't need a frontier model. Weave Router fixes that. It analyzes your prompt and routes it to the highest quality model with the lowest cost (across open and closed source models). This all happens in your current workflow on Claude, Cursor or Codex so you don't have to change a thing. Early customers have seen an ~70% reduction in costs without any slowdowns. Source code available.