Software Engineering Intern (Fall 2026)

Double Holo is building the market intelligence platform for trading cards. Collectors and vendors already use Double Holo to buy, sell, and analyze cards through live bid/ask order books, pricing analytics, slab scanning, AI-powered recommendations, grading ROI, and expected value calculations. The trading card market moves hundreds of millions of dollars every year, yet many buying decisions are still driven by intuition instead of data. Our goal is to bring institutional-quality analytics to one of the world's fastest-growing collectibles markets. Our web platform and mobile app are both live, and we're shipping new features every week. Software Engineering Intern We're looking for an intern who wants to ship real software to real users, not sit in a sandbox. This isn't a coffee-and-slideshows internship. You'll commit code to production in your first two weeks, and features you build will be in the hands of thousands of collectors before your internship ends. You'll work directly with the founders and our engineers across the full stack: the Rails API that powers the marketplace, the Next.js web platform, and the React Native mobile app. If you want your resume to say "built and shipped features used by a passionate community every day" instead of "assisted the team with various tasks," keep reading. What You'll Work On You’ll pick up real items from the same roadmap as the rest of the team, scoped so you can own them end to end. Depending on your interests, that could include: Building marketplace features across the Next.js web app: listings, order books, seller tools Shipping API endpoints in Rails that power pricing analytics and intelligence Bringing web features to our React Native app, or mobile features to web Writing data pipelines and background jobs that keep prices, sales, and population data fresh Improving internal tools our team uses to manage the marketplace every day Chasing real production bugs from a Sentry report to a shipped fix Every intern project ships. Nothing you build goes in a drawer. You’ll Be Successful If You… Have built something real: a class project you took further than required, a personal app, an open source contribution, a hackathon build you actually finished Ask questions early instead of spinning silently Like feedback, because you’ll get it fast: our community tells us what they think of a feature within hours of shipping Can work from curiosity: "why is this slow?" and "what happens if I tap this twice?" are the questions that find the good problems Bonus points if you’ve touched React, React Native, Rails, SQL, or payments. Collecting trading cards is a plus - but definitely not required. Our Stack Next.js + TypeScript (web) React Native (Expo) Ruby on Rails API + PostgreSQL Stripe + RevenueCat Why Intern Here? Small team, zero bureaucracy: your PR gets reviewed in hours, not weeks Direct mentorship from engineers who own entire products, with real code review on everything you write Full-stack exposure in one internship: most internships show you one corner of one codebase, you’ll touch three apps and a production database An active community that reacts to your work the day it ships Strong interns get first shot at a return offer or a full-time role Compensation Paid internship, competitive hourly rate A path to a founding-team engineering role for exceptional interns #J-18808-Ljbffr