Building & Product
How founders use AI for AI in Your Product
The resources behind 15 questions founders actually ask, then the questions themselves, each with a straight answer.
On the AI map, 29 October 2026 Frontier models Open-weight models Decision models
What founders use for ai in your product, ranked by how many answers lean on it.
- The canonical guide: curation beats clever prompting for agents. anthropic.com Guide Effective context engineering for AI agents Anthropic
- The write, select, compress, isolate framework every team now uses. langchain.com Article Context Engineering for Agents LangChain
- Why context, not model size, unlocks agents that work for hours. sequoiacap.com Podcast Context Engineering Long-Horizon Agents | Harrison Chase Sequoia Training Data (Harrison Chase)
- A clear decision framework for the exact moment every founder faces: bolt on AI, ignore it, or rethink the product. founderprompts.com Article "Should we add AI?" Here is how to decide Vasil (Founder Prompts)
- The UX research heavyweights on why novelty chatbots harm products and what user value actually looks like. nngroup.com Article AI Features Must Solve Real User Problems Nielsen Norman Group
- A blunt scorecard of which AI product ideas changed user behaviour and which quietly flopped. a16z.com Article State of Consumer AI 2025: Product Hits, Misses, and What's Next a16z
- Four consumer investors on why subtle product choices now matter more than raw model quality. a16z.com Podcast Where Does Consumer AI Stand at the End of 2025? a16z (Anish Acharya, Olivia Moore, Justine Moore, Bryan Kim)
- The canonical reframe: sell the finished work, not a 15% productivity tool, and your market gets 10-50x bigger. sarahtavel.com Article AI startups: Sell work, not software Sarah Tavel (Benchmark)
- Tavel pressure-tests her own thesis with what she has since seen in real AI startups. sarahtavel.com Article A few "Sell Work, Not Software" updated thoughts Sarah Tavel (Benchmark)
- Veteran product leaders on AI at the core versus AI at the edge, the distinction most founders miss. lennysnewsletter.com Podcast How AI is reshaping the product role | Oji and Ezinne Udezue Lenny's Podcast
- YC group partners distil patterns from hundreds of AI startups they funded, including what users reward. ycombinator.com Podcast The Truth About Building AI Startups Today (Lightcone Ep. 1) Y Combinator (Lightcone Podcast)
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Video
A Cheeky Pint with Intercom Cofounder Des Traynor
Cheeky Pint (John Collison, Stripe)
- The full transcript, including the memorable rule against force-feeding users AI they never asked for. cheekypint.substack.com Article Des Traynor on reinventing Intercom and avoiding "foie gras" features Cheeky Pint (Stripe)
- A rare honest post-mortem from a product team on which AI bets worked in production and which had to be killed. hex.tech Article Bitter lessons building AI products Hex
- Includes Carta's hard-won lesson on separating model behaviour from UX when shipping AI features. review.firstround.com Article The 30 Best Pieces of Company Building Advice We Heard in 2025 First Round Review
- Vohra applies his famous product-market-fit engine to deciding which AI features earn their place. productschool.com Podcast Superhuman CEO on the 40% PMF Rule and AI-Native Productivity Product School (Rahul Vohra)
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Video
Rahul Vohra on How AI Will Change the Way We Work (Upfront Summit)
Upfront Ventures
- A top consumer investor answers the exact question, drawn from hundreds of a16z Speedrun applications. x.com Thread "Does my new startup idea need to have AI in it?" Andrew Chen (a16z)
- A data company's candid recap of which of its own AI features users adopted and why. amplitude.com Article What We Learned Building AI Products in 2025 Amplitude
- A case study of an incumbent rebuilding around one AI feature that customers demonstrably pay for. bvp.com Article How Intercom navigated the AI paradigm shift Bessemer Venture Partners
- The sharpest counterargument you will read; know the backlash before you ship an unwanted AI feature. honest-broker.com Article The Force-Feeding of AI on an Unwilling Public Ted Gioia (The Honest Broker)
- A respected discovery coach documents what surprised her when she actually built an AI product herself. producttalk.org Article Building My First AI Product: 6 Lessons from My 90-Day Deep Dive Teresa Torres (Product Talk)
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Video
[1hr Talk] Intro to Large Language Models
Andrej Karpathy
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Video
Deep Dive into LLMs like ChatGPT
Andrej Karpathy
The questions
Should my startup add AI features, and which ones actually matter to users?
Users do not care that a feature uses AI; they care whether it removes a slow, painful, judgment-heavy step from their day. Start from a specific friction po...
How do founders ship their first AI feature (APIs, wrappers, RAG in plain terms)?
Your first AI feature is usually one API call: send the model your instructions plus the user's input, get text or structured JSON back, and wrap it in your ...
How much does it cost to run AI features, and how do I keep costs sane?
You pay per token (roughly per word) in and out, so cost scales with usage; a small feature can run on tens of dollars a month while a chat-heavy product can...
Which AI model should I build on (GPT, Claude, Gemini, open-source), and how do I avoid locking myself in?
There is no best model, only the best one for your task at your price: test the top two or three on your own examples, not benchmark headlines. Today's short...
How do I test whether my AI feature actually works before launch (evals, in plain terms)?
An eval is just a repeatable test suite for your AI feature: 30-100 real example inputs, the output you expect, and a way to score each run. Start by reading...
How do I stop my AI feature from making things up in front of customers?
Models hallucinate because they are trained to always answer; your job is to constrain them, not to hope. The biggest wins in order: ground answers in your o...
Prompt engineering, RAG, or fine-tuning: which one does my product actually need?
Work up the ladder: better prompts cost hours, RAG costs days and adds your own live data, fine-tuning costs weeks and only changes behaviour and style, not ...
How do I design AI features people trust (chat vs buttons, streaming, showing the work)?
A chat box is rarely the right interface: embedded AI (suggestions inside the existing workflow, one click to accept or reject) builds trust faster because u...
What is my moat if I'm building on someone else's model?
The model is not your moat and never will be; the moat is everything you wrap around it: proprietary data and feedback loops, deep vertical workflow ownershi...
Should I put an AI agent in my product, or is a simple workflow enough?
A workflow follows steps you defined, with the model filling in the reasoning slots; an agent decides its own path with tools in a loop. Workflows are cheape...
Is it safe to send customer data to AI APIs, and what about privacy laws like India's DPDP Act?
The major API providers (OpenAI, Anthropic) do not train on your API data by default, and Anthropic no longer keeps API prompts at all by default, except on ...
How should I price AI features: per seat, per use, or per outcome?
AI broke flat per-seat pricing because every request has a real compute cost; most AI-native companies now run hybrid pricing: a base subscription plus usage...
My AI feature is live. How do I monitor it and make it better with real usage?
Log every AI call with its prompt, response, cost, latency, and user feedback; observability tools like Langfuse or LangSmith give you this in an afternoon a...
What is RAG in AI?
RAG (retrieval-augmented generation) means the AI first looks up passages from a set of documents you choose and then answers from them, instead of relying o...
How do I get an API key for OpenAI or Gemini?
Both take a few minutes and only need a sign-in. For Gemini, open the API keys page in Google AI Studio (aistudio.google.com/apikey): new users get a default...
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