RSS preview of Lenny Rachitsky

Rss preview of Blog of Lenny Rachitsky

GPT 5.5 just did what no other model could

2026-04-24 03:39:26

In this mini episode, I break down OpenAI’s new GPT 5.5 and GPT 5.5 Pro after weeks of early testing. I walk through three real jobs I threw at the model: building an app for me to teach my second grader more advanced subtraction concepts, tackling a tech debt problem in the ChatPRD codebase, and hacking into a proprietary Bluetooth pixel display that every other model had failed me on. My verdict: higher intelligence, better efficiency, and genuinely autonomous long-running loops that change what I think is worth tackling.

Listen or watch on YouTube, Spotify, or Apple Podcasts

What you’ll learn:

How I think about GPT 5.5 Pro’s pricing vs engineering time, and when I believe the “intelligence tax” is worth paying
Why I treat GPT 5.5 as a developer model first, and why I couldn’t find a consumer use case that justified its intelligence
The exact prompt pattern I use to unlock a long-running autonomous subagent loop
How I got a near-six-hour autonomous run to one-shot 98% of edge cases in a migration over millions of chat threads and drop my Sentry error rate to the floor
Why I’m now throwing GPT 5.5 at tech debt, flaky tests, and security backlogs first
How I combined a Bluetooth packet sniffer and GPT 5.5 to reverse-engineer a proprietary pixel speaker after Claude Code and GPT 5.4 both gave up
How I use the /personality command inside Codex to swap the default “baked potato” tone for something I actually enjoy working with

In this episode, we cover:

(00:00) Introduction to GPT 5.5 testing

(00:40) What is GPT 5.5 and how much does it cost?

(03:23) Testing GPT 5.5 in ChatGPT: the intelligence overhang problem

(07:12) Moving to Codex: where GPT 5.5 really shines

(16:01) Hacking a Chinese Bluetooth speaker

(21:47) Final thoughts on GPT 5.5’s intelligence and efficiency

Production and marketing by https://penname.co/. For inquiries about sponsoring the podcast, email [email protected].

How Anthropic’s product team moves faster than anyone else | Cat Wu (Head of Product, Claude Code)

2026-04-23 23:01:50

Cat Wu is Head of Product for Claude Code and Cowork at Anthropic, building one of the most important AI products of this generation. Before joining Anthropic, Cat spent years as an engineer and briefly worked in VC. Today, she’s interviewing hundreds of product managers who are trying to break into AI—and seeing firsthand what separates those who thrive from those who fall behind.

Listen on YouTube, Spotify, and Apple Podcasts

We discuss:

How Anthropic’s shipping cadence went from months to weeks to days
The emerging skills PMs need to develop right now
Why you need to build products that don’t yet fully work, so you’re ready when the next model closes the gap
Cat’s most underrated AI skill: asking the model to introspect on its own mistakes
Why Claude’s personality is core to its success
Why Anthropic’s mission alignment eliminates the friction that slows most large organizations
Why “just do things” is the most important principle for working at AI-native companies

Brought to you by:

WorkOS—Modern identity platform for B2B SaaS, free up to 1 million MAUs

Vanta—Automate compliance, manage risk, and accelerate trust with AI

Where to find Cat Wu:

• X: https://x.com/_catwu

• LinkedIn: linkedin.com/in/cat-wu

• Newsletter: https://catwu.substack.com

Referenced:

• Head of Claude Code: What happens after coding is solved | Boris Cherny: https://www.lennysnewsletter.com/p/head-of-claude-code-what-happens

• Anthropic: https://www.anthropic.com

• Assessing Claude Mythos Preview’s cybersecurity capabilities: https://red.anthropic.com/2026/mythos-preview

• OpenClaw: https://openclaw.ai

• OpenClaw: The complete guide to building, training, and living with your personal AI agent: https://www.lennysnewsletter.com/p/openclaw-the-complete-guide-to-building

• Listen: OpenClaw: A power user’s guide to the most powerful personal AI tool since ChatGPT: https://www.lennysnewsletter.com/p/listen-openclaw-a-power-users-guide

• Dianne Na Penn on LinkedIn: https://www.linkedin.com/in/dianne-na-penn

• Head of Growth (Anthropic): “Claude is growing itself at this point” | Amol Avasare: https://www.lennysnewsletter.com/p/anthropics-1b-to-19b-growth-run

• Anthropic co-founder on quitting OpenAI, AGI predictions, $100M talent wars, 20% unemployment, and the nightmare scenarios keeping him up at night | Ben Mann: https://www.lennysnewsletter.com/p/anthropic-co-founder-benjamin-mann

• GIF from Pirates of the Caribbean: https://tenor.com/view/pirate-of-pirate-of-the-carribean-jack-sparrow-pirati-dei-caraibi-sad-gif-14519798

• What’s New post with Claude powerup feature: https://code.claude.com/docs/en/whats-new/2026-w14

• Claude Code: https://claude.com/product/claude-code

• Terminal guide for new users: https://code.claude.com/docs/en/terminal-guide

• Claude Cowork: https://www.anthropic.com/product/claude-cowork

• Anthropic’s developer conference: https://claude.com/code-with-claude/san-francisco

• Figma MCP: https://www.figma.com/mcp-catalog

• Salesforce: https://www.salesforce.com

• Gong: https://www.gong.io

• Slack founder: Mental models for building products people love ft. Stewart Butterfield: https://www.lennysnewsletter.com/p/slack-founder-stewart-butterfield

• Why AI evals are the hottest new skill for product builders | Hamel Husain & Shreya Shankar (creators of the #1 eval course): https://www.lennysnewsletter.com/p/why-ai-evals-are-the-hottest-new-skill

• Beyond vibe checks: A PM’s complete guide to evals: https://www.lennysnewsletter.com/p/beyond-vibe-checks-a-pms-complete

• Building eval systems that improve your AI product: https://www.lennysnewsletter.com/p/building-eval-systems-that-improve

• Why experts writing AI evals is creating the fastest-growing companies in history | Brendan Foody (CEO of Mercor): https://www.lennysnewsletter.com/p/experts-writing-ai-evals-brendan-foody

• Judging by my tl there is a growing gap in understanding of AI capability: https://x.com/karpathy/status/2042334451611693415

• Formula 1: Drive to Survive on Netflix: https://www.netflix.com/title/80204890

• Free Solo on National Geographic: https://films.nationalgeographic.com/free-solo

• Alex Honnold: https://en.wikipedia.org/wiki/Alex_Honnold

• Waymo: https://waymo.com

Recommended books:

• How Asia Works: https://www.amazon.com/How-Asia-Works-Joe-Studwell/dp/0802121322

• The Technology Trap: Capital, Labor, and Power in the Age of Automation: https://www.amazon.com/Technology-Trap-Capital-Labor-Automation/dp/0691210799

• The Paper Menagerie and Other Stories: https://www.amazon.com/Paper-Menagerie-Other-Stories/dp/148142436X

Production and marketing by https://penname.co/. For inquiries about sponsoring the podcast, email [email protected].

Lenny may be an investor in the companies discussed.

My biggest takeaways from this conversation:

What Claude Design is actually good for (and why Figma isn’t dead yet)

2026-04-22 20:04:31

In this mini episode, I do a full walkthrough of the AI design tools that dropped in April 2026: Anthropic’s new Claude Design, OpenAI’s GPT Images 2.0, and Google Labs’ open-source DESIGN.md format. I import a full design system from Lenny’s Newsletter, build a landing page, turn my own article into a polished deck, generate a brand kit for ChatPRD, and run a personal color analysis from a photo.

Listen or watch on YouTube, Spotify, or Apple Podcasts

What you’ll learn:

How Claude Design handles design system imports and whether it can actually replace Figma
The three best use cases for Claude Design: marketing landing pages, slide decks, and creative redesigns
Why ChatGPT Images 2.0 is a breakthrough for brand kits and layout work
Google’s new DESIGN.md standard
The practical limits of AI design tools (spoiler: you’ll hit credit limits fast)

Brought to you by:

WorkOS—Make your app enterprise-ready today

Rippling—Stop wasting time on admin tasks, build your startup faster

In this episode, we cover:

(00:00) Welcome and what’s in the spring 2026 AI design drop

(01:45) Claude Design overview

(03:05) Importing Lenny’s Newsletter design system into Claude Design

(04:06) How Claude Design structures a design system

(05:42) Google Labs’ DESIGN.md standard

(06:41) Building Lenny Doc, a PRD generator landing page using the Lenny design system

(09:44) Why the three-variation output is Claude Design’s smartest UX choice

(10:20) Hitting the Claude Design limit and paying $200 to keep going

(11:05) Where Figma still wins

(13:20) Reviewing Lenny Doc

(16:19) Turning an Open Claude article into a branded slide deck

(17:57) The ’90s GeoCities “Lenny’s Product Zone” redesign

(19:44) Claude Design recap

(20:15) ChatGPT Images 2.0 and what makes it the first “thinking” image model

(21:25) Generating a multi-page brand kit for ChatPRD and iterating with reference images

(23:43) Personal color analysis demo

(26:02) Recap

Tools referenced:

• Claude Design: https://claude.ai/design

• ChatGPT Images 2.0: https://openai.com/index/introducing-chatgpt-images-2-0/

• Midjourney: https://www.midjourney.com/

Other references:

• Google’s DESIGN.md: https://stitch.withgoogle.com/docs/design-md/overview

• Lenny’s Newsletter: https://www.lennysnewsletter.com/

• Jamie Gannon “How I AI” episode on reference styles: https://www.lennysnewsletter.com/p/mastering-midjourney-how-to-create

• Brand prompt inspiration: https://x.com/riomadeit/status/2046682442791071787

• Figma team “How I AI” episode on design systems: https://www.lennysnewsletter.com/p/from-figma-to-claude-code-and-back

Where to find Claire Vo:

ChatPRD: https://www.chatprd.ai/

Website: https://clairevo.com/

LinkedIn: https://www.linkedin.com/in/clairevo/

X: https://x.com/clairevo

Production and marketing by https://penname.co/. For inquiries about sponsoring the podcast, email [email protected].

New: A free year of Cursor, Google AI Pro, Notion, Supabase, Gumloop, and Fin for subscribers

2026-04-21 23:03:33

👋 Hey there, I’m Lenny. Each week, I answer reader questions about building product, driving growth, and accelerating your career.

Subscribe now

My mission with this newsletter (and podcast) is to give you the advice, community, and tools you need to build a world-class product and career. Because things are changing so fast, there’s a growing divide—in terms of career opportunities, financial outcomes, and how much you enjoy your work—between the people who benefit from the transformation we’re living through and those who get left behind. I want to make sure you’re in the first group.

To further that mission, I’m thrilled to announce that Lenny’s Product Pass now includes a free year of six additional incredible premium products:

Cursor* ($240 value): The best way to build software with AI.
Google AI* ($240 value): Higher access to Gemini, NotebookLM, Antigravity, Nano Banana, Flow, 5 TB of cloud storage, and more.
Notion ($240 value): Collaborative AI workspace where teams and agents work together.
Supabase* ($300 value): An all-in-one, easy-to-use, open-source managed Database, Auth, Storage, Edge Functions, Realtime, and Vector search.
Fin + Intercom (5 seats and $100/month in AI outcome credits, $7,140 value): Deliver perfect customer experiences with the #1 AI customer service agent.
Gumloop ($444 value): Build agents across all your apps and share them with your team. No engineering required.

→ Already a paid subscriber? Grab your free products here.
→ Not yet a subscriber? Subscribe and then grab your free products here.

I’m also super-excited to welcome back Replit and Gamma* to the Product Pass!

This is on top of the 17 premium products already available to subscribers: Canva Pro*, ChatPRD, ElevenLabs*, Factory, Framer, Granola, Linear, Lovable*, Magic Patterns, Manus, Mobbin, n8n*, PostHog, Railway, Stripe Atlas*, Warp, and Wispr Flow.

* These products are available for Insider-tier subscribers only

The total value of the Product Pass is now over $30,000. That’s 25 of the hottest, most important, and most beautifully crafted products in the world, free with your Lenny’s Newsletter subscription.

This all sounds way too good to be true, but it isn’t.

Many readers expense this subscription out of their workplace’s learning and development budget. Here’s an email you can send to your manager.

How to redeem these offers:

Step 1: Get an Annual or Insider subscription to Lenny’s Newsletter.
Step 2: Redeem your codes here.
Step 3: Have fun!

A note about how I hope you’ll approach these offers

The Product Pass is a community-powered collaboration. Many of these companies are brand-new and very excited for our community to try their products. Companies aren’t paying to be in the Product Pass, and I only include tools that I love and recommend. Similarly, my (very small) team is working hard to make this a seamless experience. Things will break, codes will run out, and I promise we’ll do our very best to resolve issues as fast as we can. Ultimately, my core offering is this newsletter, the podcast, and the community. These deals are the cherry on top.

What are the new products?

1. Cursor Pro* ($240 value)

What it is: The best way to build software with AI.

How people use it:

Building a personal OS (while building AI product sense)
Structuring AI workflows to build and ship real products (even as a non-technical builder)
Accelerating PR velocity and code quality at scale

2. Google AI Pro** ($240 value)

What it is: Get higher access to the newest and most powerful features in Gemini, Flow, and NotebookLM, as well as AI-powered assistance from Gemini directly in the Google apps you know and use. Plus, you get 5 TB of cloud storage to keep photos and files backed up.

How people use it:

Coding beautiful 3D pixel art based on a single image prompt
Building a physics-consistent ocean waves simulator
Using Nano Banana 2 to create video game backgrounds, UI design, home renovations, and highly detailed imagery

3. Notion Business ($240 value)

What it is: Collaborative AI workspace where teams and agents work together.

How people use it:

Running a Weekly Briefing agent that generates a summary of key updates, what’s coming up, and what needs attention that week
Building out an AI operating system for work, giving everyone at the company a personal Notion agent and cutting productivity-tool costs at Ramp
Using Notion as a lean “OS” where AI answers questions instantly, new hires onboard themselves, and every team builds exactly what they need at Cursor

Building a Scheduling Assistant agent that does meeting prep—automatically creating meeting notes, linking them to a CRM, and updating calendar events with links

4. Supabase Pro* ($300 value)

What it is: An all-in-one, easy-to-use, open-source managed Database, Auth, Storage, Edge Functions, Realtime, and Vector search.

How people use it:

Building an app to learn English
Crafting a tool to upscale images and generate videos
Hosting the database and analytics for a bulk URL shortener
Creating an open source app for finding a home for your food scraps

5. Fin AI Agent + Intercom Advanced (5 seats and $100/mo credits in AI outcomes, $7,140 value)

What it is: Deliver perfect customer experiences with an AI Customer Service Agent.

How people use it:

Transforming support operations for Anthropic
Supporting 50M users with 20 agents and Fin for Gamma
Involving Fin in 90% of support queries and resolving 50% over email, chat, and Slack for Clay

6. Gumloop Pro ($444 value)

What it is: An AI agent-building platform that makes it effortless for anyone on your team (not just engineers) to collaborate on and deploy agents. Describe exactly what tasks you want the agent to perform, when, and with which apps, and the agents will build themselves.

How people use it:

Using Gumloop agents to coach sales reps, prepare for renewal meetings, and monitor for clients at risk of churning at Gusto
Instantly answering data analytics questions and making visualizations with an agent that any team member can @ in Slack
Building a sales agent that can update your CRM and research and schedule meetings with customers
Creating an automated personal assistant agent integrated with Granola MCP that can draft its own emails, Slack messages, and Linear tickets
Running an entire global support operation by giving two humans a team of interconnected, specialized AI agents

Important offer details (read before subscribing):

For each product, you must be a new customer to take advantage of the free year. If you’ve already paid for one of the products yourself (monthly or yearly) or redeemed a code from one of our previous bundles, you won’t be able to get a free additional year of that specific product.
You must get an Annual or Insider subscription to Lenny’s Newsletter to be eligible for this offer. Monthly subscribers aren’t eligible.
Both existing and new subscribers of Lenny’s Newsletter are eligible for this deal. Existing subscribers can redeem the offer here.
We may run out of codes for a product at any time. Your code is only secured once you claim it. You need to claim each code individually, so hop on the products you are most excited about.
Your access to the Product Pass is contingent on your subscription remaining active. If you cancel or don’t renew your paid subscription at any time, your codes and active trials may be deactivated.
Your one free year of the product begins when you redeem the deal on the partner’s website, not when you purchase this newsletter subscription or claim your code.
All sales are final once you redeem your first code. We won’t issue refunds if a couple of products are out by the time you claim them. The deal is already so good, even if a couple of products are missing. If you request a chargeback for your subscription, all of your codes will be deactivated. We need to do this to avoid fraud.

To summarize, your paid subscription now includes:

A deeply researched newsletter and podcast with a 5+ year back catalog of evergreen content
A 30,000+ members-only global Slack community with local meetups, AMAs, mentorship programs, book clubs, and more
This growing collection of premium tools

It’s everything you need to build a world-class product and career.

Subscribe now

* These products are available for Insider-tier subscribers only
** Google AI Pro’s $239.88 value is based on monthly recurring subscription price. Redeem the offer by December 31, 2026, at 11:59 p.m. PT. Cancel anytime. Gemini in Google AI Pro and Gemini for Gmail, Docs, and more are only available for ages 18+. Gemini for Gmail, Docs, and more is available in select languages. Existing Google One users can redeem this offer, but this free trial period cannot be added to an existing free trial. Users can only use one trial at a time, and promotion lengths are not stackable. If a user has an existing trial and redeems a new trial, their existing trial or subscription plan will be revoked and their new trial will begin, regardless of how much time they have left on their existing offer. The offer is not available to: Google One users subscribed to an add-on, Google One users subscribed to a higher-tier plan than the one being offered, Google One users on a family plan who are not the plan manager, Google One users who have a Google One subscription through a third party or affiliate. See full terms.

If you’ve already got a subscription, consider gifting a subscription to a colleague or purchasing a group subscription for your team.

Sincerely,

Lenny 👋

🎙️ This week on How I AI: How Intercom 2x’d their engineering velocity with Claude Code

2026-04-20 23:33:11

How Intercom 2x’d their engineering velocity in 9 months with Claude Code | Brian Scanlan

Listen now on YouTube • Spotify • Apple Podcasts

Brought to you by:

Celigo—Intelligent automation built for AI

Cursor—The best way to code with AI

Brian Scanlan, Senior Principal Engineer at Intercom, breaks down how the company doubled engineering throughput in just nine months by going all-in on Claude Code. He shares how custom skills, deep telemetry, and a culture of permission turned AI into a true force multiplier.

Biggest takeaways:

Treat your engineering org like a product, and instrument everything. Intercom tracks skill invocations in Honeycomb, stores anonymized Claude Code sessions in S3, and built custom dashboards that show engineers how they compare to peers. This isn’t surveillance—it’s the same product thinking you’d apply to customer-facing features. You can’t improve what you don’t measure, and you can’t scale AI adoption without visibility into what’s working and what’s breaking.
The 2x velocity gain is real, but only if you prepare your foundation. Intercom doubled their merged PRs per R&D employee in nine months, but they already had mature CI/CD, comprehensive test coverage, and a high-trust culture. AI magnifies your strengths and weaknesses—if your deployment pipeline is broken or your code review process is manual chaos, AI will just help you ship broken code faster. Fix your fundamentals first, then pour gasoline on the fire.
Custom skills with hooks enforce quality at the point of creation, not after the fact. Intercom’s “Create PR” skill blocks Claude Code from using the GitHub CLI directly and forces it to write context-rich PR descriptions instead of just regurgitating code. Build guardrails that make the golden path the only path.
Code quality improves when you ship twice as fast because you finally have capacity for tech debt. Intercom’s partnership with Stanford researchers shows their code quality metrics are going up, not down. When the cost of fixing flaky tests, improving developer experience, and tackling technical debt compresses to near-zero, you can actually do those things instead of just talking about them in retros. The business constraint on internal projects disappears when agents can execute them in hours instead of quarters.
The most important job of technical leadership in the AI era is giving permission and taking accountability. Brian’s framework is simple: Tell people they can do things, and if anything goes wrong, blame me. Engineers don’t need more tutorials or documentation; they need permission to connect Claude Code to Snowflake, to ship code from their phone on the subway, to build a CLI that bypasses email verification. The activation energy for experimentation is cultural, not technical.
Make your product agent-friendly or watch customers build it themselves. Brian built an Intercom CLI that can autonomously sign up for Fin, verify email addresses by accessing Gmail, and complete installation without human intervention. If you don’t build this, your customers’ agents will just brute-force your website, burn more tokens, get frustrated, and eventually press escape and build it themselves. The switching cost is literally one keystroke. Your conversion funnel is now invisible, and your drop-off point is “forget it, let’s do this a different way.”
All work will become agent-first, and you should set a deadline for it. Brian’s vision is that by the end of any given month, the first response to an alarm, a planning meeting, or a customer question should be an agent doing the basic work. This isn’t aspirational—it’s a realistic expectation given the current state of models and harnesses. The bottleneck isn’t the technology; it’s organizational willingness to reimagine workflows from first principles and give people permission to experiment.

Detailed workflow walkthroughs from this episode:

How Intercom Doubled Engineering Output: Brian Scanlan’s 4 AI Workflows for Claude Code: https://www.chatprd.ai/how-i-ai/how-intercom-doubled-engineering-output-brian-scanlan-ai-workflows-for-claude-code
Design an Agent-Friendly CLI to Automate SaaS Product Onboarding: https://www.chatprd.ai/how-i-ai/workflows/design-an-agent-friendly-cli-to-automate-saas-product-onboarding
Build a Self-Improving AI Agent to Automatically Fix Flaky Tests: https://www.chatprd.ai/how-i-ai/workflows/build-a-self-improving-ai-agent-to-automatically-fix-flaky-tests
Automate High-Quality Pull Request Descriptions with a Custom AI Skill: https://www.chatprd.ai/how-i-ai/workflows/automate-high-quality-pull-request-descriptions-with-a-custom-ai-skill

If you’re enjoying these episodes, reply and let me know what you’d love to learn more about: AI workflows, hiring, growth, product strategy—anything.

Catch you next week,
Lenny

P.S. Want every new episode delivered the moment it drops? Hit “Follow” on your favorite podcast app.

How Intercom 2x’d their engineering velocity in 9 months with Claude Code | Brian Scanlan

2026-04-20 20:03:25

Brian Scanlan is a senior principal engineer at Intercom, where he’s led the company’s transformation to AI-first engineering. In just nine months, Intercom doubled their R&D throughput while maintaining code quality, with 100% of engineers—plus designers, PMs, and TPMs—now shipping code via Claude Code.

Listen or watch on YouTube, Spotify, or Apple Podcasts

What you’ll learn:

How Intercom doubled their merged PRs per R&D employee in just nine months using Claude Code
The telemetry infrastructure they built to measure AI adoption and quality across hundreds of engineers
Why they built a skills repository with hooks that enforce engineering standards automatically
How they’re preparing their product for an agent-first world with CLIs, MCPs, and ephemeral APIs
The permission and accountability framework that enabled rapid AI adoption
Why backlog zero is now achievable and what that means for engineering culture