Signpost Spring 2026 Founders Jerry Xiao check_circle Profile complete keyboard_arrow_down Basics Name Jerry Xiao Email jerry.x0930@gmail.com Phone Number +15109009898 Age 18 Gender Male City where you currently live Oakland, California, US Role What is your title, or if you haven’t set it yet, main responsibility? CEO What percent equity do you have? 50 Do you have at least 10% equity in the company you're applying with? yes Are you a technical founder? yes Are you currently in school? yes Will you have graduated by the time the batch starts? no Walk us through your thinking around balancing your startup, school, and any other obligations. I plan to drop everything and pursue this full time. My parents are now doing fine with their noodle shop so there's nothing really holding me back. If accepted to YC, will you commit to working exclusively on this project for the next year? yes Background Your LinkedIn URL https://www.linkedin.com/in/xiaojerry/ Education Northeastern University Aug 2025 - Apr 2028 BS, Computer Science Stephen F. Austin High School Dec 2020 - Dec 2024 High school diploma, Multi Work Experience AurusFi - Founding Engineer Nov 2025 - Present Built proprietary data pipelines and Azure functions that ingest data from Polymarket, Kalshi, and other market prediction platforms.
Rule Your Own Game Inc. - Software Engineer Nov 2025 - Present Collaborated with the ownership team to overhaul software infrastructure and web systems to support 3M+ monthly visits, focusing on driving revenue through integrated monetization features and web-based shop optimizations. Architected persistent data systems for gamemodes and developed web-to-game sync protocols that maximized player retention and lifetime value.
Costly - Founder Jun 2024 - Present Stake money for your focus session: break focus, lose money. Formerly known as Unbind. Originated from a mock start-up pitch at the Stanford Entrepreneurship Olympiad (TechDev Academy). ~125 waitlist signups.
HP - Corporate Venture Analyst Extern Jul 2024 - Sep 2024 Analyzed startups for HP’s corporate VC firm, assessing founders and use cases, and pitched opportunities to senior leadership with projection‑backed investment memos and risk analyses.
Horizons - Technology Officer May 2022 - Apr 2025 Led Solace’s Fusion 360‑designed solar modular battery‑pack concept, enabling interchangeable modules & app‑driven feature and module management design + other various projects throughout high school under Junior Achievement.
Classic Guilin Rice Noodles - Busboy Apr 2021 - Nov 2023 Managed 50–100+ daily POS transactions, delivered Mandarin/Cantonese service that kept reviews 4 stars up, and drove a 25% jump in average check size through compliant upselling.
Social Media Github URL https://github.com/undeemed Accomplishments Please tell us about a time you most successfully hacked some (non-computer) system to your advantage. I used to play hockey in middle school but eventually quit to pursue Taekwondo. I still visited the rink to skate for fun, which is when I realized they only cycled through four wristband colors. I bought one of each so that on future visits, I’d simply spot the day's color, put on my matching band from my bag, and get on the ice for free. Please tell us in one or two sentences about the most impressive thing other than this startup that you have built or achieved. Frontend ad monetization changes helped boost Rule Your Own Game Inc. estimated MRR from $5k to $40k.
143 win streak in Minecraft Hypixel Duels. Tell us about things you've built before. For example apps you’ve built, websites, open source contributions. Include URLs if possible. https://costly.live - landing page and waitlist sign up for Costly.
https://github.com/Northeastern-Research-ORNL-1/pyreflect-interface - Research Project
https://github.com/undeemed/Payless.chat - Do surveys in your IDE to earn AI usage.
https://github.com/undeemed/SEC-Tracker - CLI Tool Stock Filing Analysis
https://github.com/shlawgathon/WebBrain: An AI-powered browser history recall tool that finds past web visits based on your descriptions.
https://github.com/shlawgathon/ICBG: A logistics platform where Santa can remotely send gifts using a nukemap interface.
https://github.com/shlawgathon/physical: A marketplace and analytics platform described as the "Airbnb/Zillow" for physical advertising spaces.
https://github.com/shlawgathon/productkit: A tool that generates Shopify listings from images and creates 3D assets with AR interactions in one click.
https://github.com/shlawgathon/sportsclips: A video pipeline using Gemini detection to create TikTok-style sports highlights and live commentary. Prod ready Swift app in <24 hours.
https://github.com/undeemed/get-shit-done-codex: A light-weight and powerful meta-prompting, context engineering and spec-driven development system for Codex, originally by TÂCHES. ~600 total installs: https://www.npmjs.com/package/@undeemed/get-shit-done-codex List any competitions/awards you have won, or papers you’ve published. Black Belt Taekwondo AP Scholar and AP Capstone Research: https://github.com/undeemed/Portfilo/tree/main/research DECA state 2x Junior Achievement Award 3x MongoDB Hackathon 3rd YC Full Stack Hackathon Top 6 Dedulus Labs Hackathon 1st List any relevant or impressive test scores. 1400 SAT 4.2 High School GPA List any entrepreneurship programs, clubs, or hacker houses you have participated in or are currently participating in. Web Development and Design - Taught HTML, CSS, and basic JS Oasis breakdancing club - VP / Stage Performer The Leukemia & Lymphoma Society - Raised money hosting events and challenges with groups across Texas and Louisiana, our team raised over $18,000 in total. Max Castagnoli check_circle Profile complete keyboard_arrow_down Basics Name Max Castagnoli Email maxrayne98@gmail.com Phone Number +17148203293 Age 18 Gender Male City where you currently live Huntington Beach, California, US Role What is your title, or if you haven’t set it yet, main responsibility? CTO What percent equity do you have? 50 Do you have at least 10% equity in the company you're applying with? yes Are you a technical founder? yes Are you currently in school? yes Will you have graduated by the time the batch starts? no Walk us through your thinking around balancing your startup, school, and any other obligations. My club hockey team is ending, so I will have tons of time to work on this startup and devote myself to making something amazing. If accepted to YC, will you commit to working exclusively on this project for the next year? yes Background Your LinkedIn URL https://www.linkedin.com/in/max-castagnoli-1b18b923b/ Education Edison High School Aug 2022 - Jun 2026 HS, General Education Work Experience Rule Your Own Game, Inc. - Software Engineer Oct 2024 - Present Worked with the ownership team to revamp their software infrastructure for an increased user base. Mainly focused on quality-of-life features for their Minecraft server. Was the main architect behind the server's persistent gamemodes and wrote code to handle 2,000,000+ users and their persistent data (individual and group-based).
Scala Studios - Junior Software Engineer Jul 2023 - Sep 2024 Worked with the project lead on the infrastructure and user experience for many Minecraft servers.
Matrix studios - Founder and Lead Software Engineer Sep 2022 - Oct 2024 Matrix Studios is an open-source development organization that specializes in giving free quality-of-life software to people who may need it.
Social Media Github URL https://github.com/98ping Accomplishments Please tell us about a time you most successfully hacked some (non-computer) system to your advantage. I go to my local hockey rink all the time for stick time (like shooting practice) and free skates, and I noticed that the sticker they use to track who actually paid for the ice was a little flawed. I could keep using the same sticker on my jersey over and over as long as it was the same day of the week at the same time. When I went back the next week, boom, it worked flawlessly. I soon then reported it to the rink staff, who, admittedly, did not really care. Please tell us in one or two sentences about the most impressive thing other than this startup that you have built or achieved. The most impressive thing, other than the startup I built or the achievements I've had, was definitely working with some of my closest friends to build a giant Minecraft server that hosted millions of players. A simple game I played as a child led me to become a software engineer I could only dream of, and I had tons of fun doing it! Tell us about things you've built before. For example apps you’ve built, websites, open source contributions. Include URLs if possible. The things I have built before are very diverse, but what I am most proud of is my work at Rule Your Own Game, Inc. The team and I have open-sourced our entire minigames framework, which has handled 10+ million games and easily hosts 50+ game servers. The link is: https://github.com/ArchMC-Development/minigames. I have spent many of my childhood years devoting myself to Minecraft development, and I believe this experience shows I can work in more than just a Minecraft setting. List any competitions/awards you have won, or papers you’ve published. I have won character and student awards from my high school, as well as awards from my hockey club. The hackathon scene where I live has been a bit dry, but I hope to get out to more soon! List any relevant or impressive test scores. SBAC Lexile Measure: 2681, SBAC Quantile Measure: 2662. List any entrepreneurship programs, clubs, or hacker houses you have participated in or are currently participating in. I have participated in my school's Digital Marketing Club, conducted research for other Robotics Clubs, and demonstrated leadership as a captain on my school's ice hockey team. How long have the founders known one another and how did you meet? Have any of the founders not met in person? We met 2 years ago on a discord group chat and worked together at Rule Your Own Game Inc., primarily remotely but have met in person a few times. Through various disagreements, we developed a dynamic where we debate decisions rigorously but resolve conflicts quickly without ego.
For example, recently Max could not fly to SF for our founder video, as an additional absence would've disqualified his high school diploma. Instead of letting this become a blocker, Jerry booked a flight on the same day so we could film and ship the application on time, and Max agreed to cover half the flight. Who writes code, or does other technical work on your product? Was any of it done by a non-founder? Please explain. We write 100% of the code ourselves. No non-founder has done any technical work.
Jerry focuses on the iOS client (Swift), frontend development, and misc. pipelines, while Max builds the backend and computer vision pipeline (TensorFlow/Mediapipe).
We are both full-stack capable and can build production-level systems. Are you looking for a cofounder? We are currently not looking for an additional cofounder. Founder Video Company Company name Signpost Describe what your company does in 50 characters or less. AI platform to help you develop your ASL signing Company URL, if any https://signpost.cv Demo Video Please provide a link to the product, if any. https://demo.signpost.cv N/A What is your company going to make? Please describe your product and what it does or will do. We are building an AI-powered ASL platform that helps students develop their signing skills through real-time feedback.
While hand-tracking technology currently exists in academic research and raw demos, it has never been productized for education; as a result, learners are still stuck using tools that rely on passive video.
Signpost packages this raw technology into a consumer-ready computer vision pipeline that provides instant corrections on hand positioning and movement. Our goal is to become the "Duolingo for ASL"—acting as a force multiplier for human instructors by giving students effective, data-driven practice between and during classes. Where do you live now, and where would the company be based after YC? San Francisco, USA Explain your decision regarding location. We need to be in SF to access the highest density of AI talent to refine our computer vision models and GTM talent to help us scale this curriculum to school districts countrywide. The Bay Area is also a hub for Deaf education (e.g., California School for the Deaf, Fremont), providing a vital feedback loop with the community. Progress How far along are you? Product: MVP is 100% complete. web prototype and computer vision pipeline are functional; currently finalizing the curriculum.
Users: Secured a pilot with Max's High School to launch with ~200 students. We are currently finalizing the Letter of Intent with the lead ASL teacher and will begin testing on 2/10/2026. How long have each of you been working on this? How much of that has been full-time? Please explain. Max has worked on this since August 2025. Jerry joined in November 2025. We are currently transitioning out of our roles at Rule Your Own Game Inc. and will be full-time starting this summer. What tech stack are you using, or planning to use, to build this product? Include AI models and AI coding tools you use. Swift for iOS, TypeScript for web frontend and backend. We use TensorFlow and MediaPipe for real-time hand tracking (processed server-side for model complexity/accuracy, with low-latency optimizations). We use Claude (Antigravity) and Codex CLI (code review) for rapid feature development and are using AI agents to automate our end-to-end testing and QA feedback from testers. This allows us to maintain stability while shipping daily updates with just the two of us. Optional: attach a coding agent session you're particularly proud of. Unanswered Are people using your product? Yes How many active users or customers do you have? How many are paying? Who is paying you the most, and how much do they pay you? Active Users: 2 internal testers (us).
Committed Users: 200 students signed up for our pilot launching on 2/10/2026.
Paying Users: 0.
Revenue: We are currently offering the product for free to validate efficacy during the pilot. Do you have revenue? no If you are applying with the same idea as a previous batch, did anything change? If you applied with a different idea, why did you pivot and what did you learn from the last idea? This is our first application. If you have already participated or committed to participate in an incubator, "accelerator" or "pre-accelerator" program, please tell us about it. We have not. Idea Why did you pick this idea to work on? Do you have domain expertise in this area? How do you know people need what you're making? Max (high school senior) picked this because he has lived the problem for over 2 years: his daily 52-minute ASL class yields only ~8 learned signs because the teacher cannot provide simultaneous feedback to 30 students.
Jerry joined to prove the solution works: he has zero prior ASL knowledge and is learning the language exclusively through our product. His progress serves as the ultimate validation that our platform actually works, even when he has a full time job as a cofounder.
We have the technical expertise to execute this because we wrote 100% of the code ourselves, building a proprietary computer vision pipeline (TensorFlow/MediaPipe) from scratch. We validated the market need by securing a pilot with Max’s high school to launch with ~200 students in March. Who are your competitors? What do you understand about your business that they don't? Our primary competitors are Lingvano and ASL Bloom. They are effectively media production studios: they differentiate via high-quality video content but rely on passive playback that offers zero feedback.
They cannot simply "add" computer vision because their architecture is built for static streaming, not real-time inference. To match us, they would need to rebuild their tech stack from scratch.
We understand that while hand-tracking technology exists in academic papers and GitHub repositories, it remains fragmented and inaccessible as raw demos. We are capitalizing on this commoditization to be the first to package the tech into a standardized, credentialed curriculum—bridging the gap between raw academic research and a consumer-ready product. How do or will you make money? How much could you make? We plan to operate on a dual model:
Consumer (Immediate): $15/mo subscription. We initially target the 6.4M active ASL learners in the US as our beachhead. While capturing ~8% of this market yields $100M ARR, our ceiling is much higher. To scale, we will expand to the "hearing ally" market. Based on the ~11.5M Deaf or Hard-of-Hearing people in the US (2021 ACS), we estimate a Total Addressable Market of ~35M learners by assuming just 3 hearing connections (friends/family) per Deaf person. Capturing just ~1.6% of this expanded market yields $100M.
Enterprise (Long-term): We will sell annual certification licenses to schools (starting with our pilot at Max's High School). This creates recurring revenue as schools purchase licenses for every new incoming class. We will establish this credential as the standard by solving the "subjectivity bottleneck." Current grading relies on human teachers who vary in strictness; our AI provides the first objective, consistent metric for fluency. By deploying into schools early, we establish our proprietary score as the only scalable benchmark for academic credit, eventually replacing slow human panels as the default "TOEFL for ASL." Which category best applies to your company? Language Learning If you had any other ideas you considered applying with, please list them. One may be something we've been waiting for. Often when we fund people it's to do something they list here and not in the main application. Physical.AI - Real time analytics and marketplace (the Zillow/Airbnb) for physical ads. Pros: Unique idea, high earning potential Cons: No expertise, needs heavy connections
Costly - Get people to stay off their devices by having them stake money for a blocked session. Pros: Unique idea Cons: Lower earning potential, hard to monetize Equity Have you formed ANY legal entity yet? no If you have not formed the company yet, describe the planned equity ownership breakdown among the founders, employees and any other proposed stockholders. If there are multiple founders, be sure to give the proposed equity ownership of each founder and founder title (e.g. CEO). (This question is as much for you as us.) Jerry Xiao (CEO): 50% Max Castagnoli (CTO): 50%
We plan to incorporate as a Delaware C-Corp via Stripe Atlas and reserve a 10-15% option pool for future employees. We also plan to adopt a standard 4-year vesting schedule with a 1-year cliff. Have you taken any investment yet? no Are you currently fundraising? no Curious What convinced you to apply to Y Combinator? Did someone encourage you to apply? Have you been to any YC events? I (Jerry) placed top 6 at the YC Full Stack Hackathon. I competed with a temporary team formed at the event where I decided to build my idea of analytics/marketplace for physical ad spaces. Afterwards, Aaron Epstein (ae@ycombinator.com) emailed to explicitly encourage an application by the Feb 9th deadline so he could schedule an interview. I am applying now with my co-founder, Max, to follow up on that invitation.
Beyond that, we’ve noticed a pattern at every Bay Area event we attend: some of the most impressive builders are invariably tied to YC. We’ve already felt the impact of this network—founders we met at casual hackathons have actively opened doors for us, connecting us with everyone from cracked high schoolers to veteran engineers who have been shipping code longer than we’ve been alive. We want to join YC to make these high-leverage collisions a daily occurrence and transition from a student project to a venture-scale company. How did you hear about Y Combinator? We follow many startups (Dedalus Labs, Play Vision, Revyl, Warp, and many more) in the tech ecosystem, and companies backed by YC often mention their participation as a key part of their journey. Batch Preference What batch do you want to apply for? future We expect almost all founders to apply for the upcoming batch. But if you are currently in school and want to graduate before doing YC, you can apply for a future batch. We run four batches a year: winter, spring, summer, and fall. Which future batch do you want to do? s2026 Why apply for a future batch rather than the upcoming one? Max is currently a high school senior. His parents have made it clear that dropping out before graduation would result in immediate disownment and a complete financial cutoff. Additionally, the school district requires parental signatures for him to unenroll, which they will not provide. Waiting for the Summer batch allows Max to secure his diploma and full independence in May, ensuring he can join YC with 100% focus rather than navigating a personal crisis that would drain company resources.