Latest Interviews

How To Design In The Agent Era

Stephen Haney, Aaron Epstein

Led by Stephen Haney, Paper is an AI-native design platform currently ranking as the third most-used tool behind Figma and Sketch, utilizing a native HTML and CSS rendering engine to facilitate precise agent collaboration. The application distinguishes itself by treating code as the single source of truth, offering features like direct React component handoff and an MCP server that allows autonomous agents to manipulate local repositories and design canvases. While the team prioritizes human curation to maintain design quality against common AI aesthetic pitfalls, the platform is rapidly evolving into a visual coordination layer for the broader agent ecosystem by integrating tools like Paper Shaders and multi-model image generation.

YC's Head of Design Shows You How To Design With AI

Eve Bouffard, Aaron Epstein, Ev Bufar

Designer Ev Bufar utilizes a voice-first workflow with tools like Aqua, Conductor, and Paper.design to rapidly produce high-fidelity assets for diverse projects, including the Paxyl transcript analyzer and the Soda Zine. Her recent work at Startup School demonstrates an agent-driven production model that generated visual identities for 6,000 attendees through custom shaders and automated speaker assets, while Paxyl analyzes coding agent interactions to reveal developer patterns. By prioritizing massive context density and disposable internal models, Bufar accelerates the design iteration cycle to handle complex branding and interactive web experiences that explicitly cater to both human users and AI agents.

Solving the Blank Canvas Problem: Gusto's AI Co-Founder

Eddie Kim, Harj Taggar

Launched in just ten weeks by a five-person team including co-founder Eddie Kim, Gusto Co-founder is a new AI product that transforms Gusto's payroll and HR data into proactive, agent-based automations for small businesses. The platform has already onboarded 500 paying customers by replacing traditional dashboards with text-based interfaces that execute complex workflows, such as full payroll processing, weather-based customer notifications, and tax credit application. This initiative validates a strategic pivot toward becoming a proactive business partner capable of lowering entry barriers for new entrepreneurs while automating compliance and growth opportunities through a "vibe coding" development methodology.

Conductor CEO Charlie Holtz Walks Us Through His AI Coding Setup

Charlie Holtz

Charlie, co-founder of Conductor, leads a team developing a macOS application that orchestrates multiple coding agents to generate software primarily in TypeScript and Rust. The platform enforces a strict non-terminal workflow where AI handles code generation while humans intervene only through specific review modes to maintain quality and prevent error cycles. With a strategic focus on high-efficiency model selection and a future roadmap emphasizing malleable, modifiable agents, Conductor positions itself as a tool that shifts software value from code itself to human-authored prompts and descriptions.

How to Make Claude Code Your AI Engineering Team

Garry Tan, Gary

Gary Tan, President and CEO of Y Combinator, has launched GStack, an open-source framework that restructures AI coding assistants into specialized engineering teams to overcome current limitations in model scaffolding. The system utilizes skills like Adversarial Review and the Office Hours query to automatically identify design flaws, generate multiple UI variants, and process hundreds of daily pull requests without traditional to-do lists. With over 70,000 GitHub stars, GStack shifts developer focus from manual coding to strategic oversight, enabling the management of parallel AI sessions to accelerate software factory operations from ideation to production.

This Startup Catches Fraud at Scale

Jared Friedman, Karine Mellata

Variance has officially exited stealth mode following a $21 million Series A round to commercialize AI agents that automate trust and safety infrastructure for Fortune 500 clients like GoFundMe and IAC. Founded by ex-Apple engineers Karine and Michael, the 12-person team leverages a unique "agentic" architecture to solve complex unstructured data problems in fraud detection and compliance without manual rule updates. Despite a 2024 leadership injury that threatened operations, the company is scaling its full-stack decisioning platform to replace traditional human review workflows with adaptive, self-healing systems designed to trace sophisticated abuse graphs.

AI Is Unlocking Millions Of New Builders

Mukund, Madhav Jha

Led by twins Mukund and Madhav Jar, Emergent is a YC Summer 2024-funded platform that empowers non-technical users to generate production-ready software through AI agents, having already built seven million apps across 190 countries. The company differentiates itself by utilizing a custom Kubernetes infrastructure and multi-agent architecture to solve the "it works on my machine" problem, while its core team achieved top-tier status on the SWE-bench benchmark within two months. By pivoting from automated testing to full-stack application development, Emergent has democratized software creation, allowing solopreneurs to launch functional products for thousands of dollars instead of the traditional half-million-dollar cost.

Fusion Energy Will Power the AI Boom

Gustaf Alströmer

Helion Energy is accelerating commercial fusion development by deploying a compact, linear machine that uses helium-3 fuel and direct energy capture to bypass traditional inefficiencies and safety concerns. The company recently secured a strategic partnership with Microsoft to power a data center, marking a pivotal shift from experimental research to real-world utility deployment. With this transition, Helion aims to establish the world's first affordable, carbon-free electricity source that cannot be weaponized, potentially transforming global energy standards within a decade.

GPT-4.5 = Big Model Energy | YC Decoded

Tom Blomfield

OpenAI has released GPT-4.5, a significantly larger and more human-like model that surpasses its predecessor in emotional intelligence and creative fluency while facing higher costs and specific limitations in complex STEM reasoning. Market reception remains measured as benchmarks show incremental rather than revolutionary improvements, leading researchers to predict a future convergence of general and reasoning capabilities in the upcoming GPT-5 architecture. Simultaneously, YC is hosting a free AI Startup School in San Francisco featuring industry leaders such as Elon Musk, Sam Altman, and Satya Nadella to support emerging AI talent.

AI Interfaces Of The Future | Design Review

Aaron Epstein, Raphael Schaad

This event analyzes the industry shift from static, noun-based interfaces to dynamic, verb-centric workflows driven by AI agents and voice technologies. Speakers highlighted emerging tools like VAPI, Gumloop, and AnswerGrid, which prioritize low-latency voice interaction, visual workflow canvases, and parallel data processing to enhance system autonomy and trust. The discussion concludes by projecting a decade-long transition toward touch-first design patterns and standardized canvas models that will fundamentally redefine software interaction paradigms.

You Don’t Have To Be A Billionaire To Launch Satellites

John Gedmark, Ryan MckLinko, Jason Carman

Eight years after transforming from a two-person apartment startup into a multi-billion dollar entity, Astronis became the first Y Combinator-backed company to successfully launch a commercial satellite into space. The firm, founded by John and Ryan, disrupted the $122 billion geostationary orbit market by securing a dedicated Falcon 9 launch for four low-cost satellites while internalizing critical manufacturing and testing processes at their Pier 70 facility. This historic achievement validates a strategy where scrappy engineering and a working prototype overcame traditional funding barriers, proving that regular domain experts can build successful hard tech aerospace companies without billionaire backing.

Why OpenAI's o1 Is A Huge Deal | YC Decoded

OpenAI has released the O1 Preview and O1 Mini models, a new class of systems designed for advanced reasoning that match PhD-level performance on complex scientific and coding benchmarks through self-generated chain-of-thought processes. Unlike previous architectures requiring manual prompt engineering, these models utilize large-scale reinforcement learning to decompose problems into verifiable steps, with accuracy improving dynamically as they allocate more "thinking time" to correct errors. While early testing shows mixed preference over GPT-4o for creative tasks, Sam Altman characterizes the technology as a foundational leap comparable to the GPT-2 stage, promising rapid evolution toward GPT-4 capabilities and future multi-modal integration within months.

Why Design Matters: Lessons from Stripe, Lyft and Airbnb

Katie Dill

Stripe Head of Design Katie Dill explains how the company unifies its creative functions to embed design directly within product squads, prioritizing intentional craft over speed to build the high level of trust required for financial transactions. By implementing rigorous quality frameworks like "Our Essential Journeys" and a "pre-flight" mindset for flaw detection, Stripe has successfully launched tools like Workbench that eliminate developer context switching while driving significant conversion gains through refined user interfaces. Dill emphasizes that founders must cultivate taste and defer to design expertise, as the resulting utility and beauty are fundamental drivers of long-term product value rather than superficial enhancements.

Stripe Head of Design Katie Dill Reviews Startup Websites

Katie Dill, Aaron Epstein

This session establishes core web design principles prioritizing immediate value clarity and mobile responsiveness while critiquing six specific healthcare and B2B technology sites. Reviewers identified critical usability failures across these platforms, including excessive scrolling on Mito Health, visual clutter on Cygnaz, and confusing brand identity on Taiv, which collectively risk user abandonment. The discussion concludes with actionable recommendations to align visual hierarchy, consistent typography, and clear calls-to-action with user scanning behaviors to boost trust and conversion rates.

Critiquing Startup Websites With Webflow CEO

Aaron Epstein, Vlad Magdalin

Aaron Group conducted a comprehensive audit of four diverse startups—Oda Studio, Flycode, Colossian, and Artifact—to evaluate how effectively their digital messaging communicates value to target audiences. The analysis highlighted critical successes in using immediate demos for AI services like Colossian and emotional storytelling for Artifact, while identifying recurring failures in audience confusion and unclear value propositions at Oda Studio and Flycode. Based on these findings, the review established a framework prioritizing above-the-fold clarity, functional demonstrations, and consolidated narratives to optimize conversion and trust across the product landscape.