Claude Code on desktop now works with the iOS simulator.
Build and run your iOS app, and the simulator opens in a panel right next to your conversation. Available today in public beta.
YC and Together AI are partnering to bring the first dedicated YC GPU cluster online, giving YC startups easier access to the compute they need to build and scale.
In this Founder Fireside, YC's @agupta and @togethercompute co-founder & CEO @vipulved dig into why compute has become one of the biggest bottlenecks for modern AI companies, how Together AI is helping more than 8,000 customers—from early-stage research teams to companies like Cursor, Cognition, and ElevenLabs—train, fine-tune, and serve AI models, and why flexible access to GPUs is becoming a competitive advantage for the next generation of founders.
00:00 — Partnering on a GPU Cluster
00:26 — What Together AI Does
01:22 — From Research Labs to Cursor: Together's 8,000 Customers
01:58 — The Landscape of AI Native Startups
03:24 — How Building an AI Company Has Changed Since 2018
04:56 — Why the Cost of Compute Keeps Going Up
05:29 — YC as the Biggest Seed Funder of Research Companies
08:47 — Flash Attention, Mamba, and the Science of Production AI
10:43 — Compute Planning Advice for Early Stage Companies
12:39 — When Your Compute Bill Is Bigger Than Your Cash Balance
13:31 — How Companies Are Using the Cluster Today
14:24 — What's Next
Most founders obsess over dashboards and aggregate metrics, but some of the best product insights come from understanding how individual users actually use their product.
In this episode of Startup School, YC's @dflieb walks through one of his favorite tools for better understanding your users, the dot plot. It's a simple two-dimensional grid that reveals usage patterns no aggregate chart can show you.
He’ll cover why it gives founders a better sense of product health, what patterns to look for, and real-world examples of how dot plots helped teams at Google Photos and PayPal.
00:52 — Why DAUs Lie to You
01:39 — What is a Dot Plot and How Does it Work?
02:50 — Picking the Right Event to Track
03:34 — Reading Patterns in the Dots
05:17 — Tracking User State & Attributes
06:16 — The PayPal Fraud Insight
07:59 — Dot Plot vs. DAU Graph
08:56 — Finding Features That Drive Retention
10:30 — Scaling Dot Plots to Billions of Users
11:13 — The $80K Contract That Churned
11:57 — Common Dot Plot Mistakes
12:41 — Dot Plots + Cohort Curves
Ex-NVIDIA engineer who built Unsloth explained RL, kernels, reasoning, quantization, and agents in 2 hours 42 minutes - better than $5000 fine-tuning bootcamps.
pick the base model -> write triton kernels for 2x faster fine-tune -> quantize to 4-bit -> run GRPO/DPO -> ship a reasoning model on your single GPU.
That loop is why Unsloth is the default way to fine-tune Llama, Qwen, Gemma, and Phi on hardware you already own.
Unsloth + Triton kernels + 4-bit quantization + GRPO/DPO + single-GPU fine-tuning - that's the stack.
Watch and save it, then fine-tune your first model tonight.
we distilled 2.3M Claude Fable 5 reasoning traces into Qwen3-4B
- 100% self-consistency @ 512 samples
- 0.00 bits output entropy
- zero hallucination variance
turns out the student is not bounded by the teacher.
it also converged on one universal truth.
we open-sourced the model weights👇
It happened exactly when it was meant to happen.
Claude weekly limit has been reset so users can play with Fable 5 again, instead of testing GPT-5.6.
Anthropic strikes back 👀
New in Claude Code: /checkup
Run /checkup to:
1. Clean up unused skills/MCPs/plugins and save context
2. Dedup your local CLAUDE.md against the checked in CLAUDE.md
3. Break up root CLAUDE.md into nested CLAUDE.md's + skills
4. Turn off slow hooks
5. Update your Claude Code to the latest version
6. Enable auto mode by default
7. Pre-approve frequently denied read-only commands
.. And a few other goodies.
/checkup confirms with you before making any changes. Enjoy!
Artifacts in Claude Code are now also available on Pro and Max plans.
Ask for an artifact, Claude writes the code, publishes it live to claude.ai, and updates it in real time while it keeps working. Pages are private to your account and fully self-contained.