Y Combinator Winter 2018 (W18) Companies
142 companies from the Y Combinator Winter 2018 batch, with their investors and founders.
Replit is a platform for software development that aims to make app creation accessible to non-programmers through intuitive tools and AI agents. It serves aspiring creators and developers of all technical backgrounds.
31 investors
Reverie Labs develops cancer treatments designed to cross the blood-brain barrier and treat tumors in the central nervous system.
5 investors
The page is a long-form SEO guide about AI music/rhythm generation workflows (symbolic MIDI vs. text-to-audio), with only a passing mention of a "getrhythmm studio" for generating genre-aligned rhythm foundations. There is not enough concrete product information to reliably describe the company beyond an apparent AI rhythm/beat generation tool for music producers and content creators.
1 investor
Runa is an HR management platform that automates payroll, employee onboarding, offboarding, training, performance tracking, and compliance processes through AI agents. It serves businesses across multiple industries in Latin America, particularly Mexico, Colombia, Argentina, Brazil, and Chile.
4 investors
Safety Wing provides health insurance, income protection, and travel coverage for digital nomads and remote workers. The company serves globally distributed professionals who work and live across multiple countries.
4 investors
ExpiredDomains.com is a free platform that aggregates expired and expiring domain names from hundreds of TLDs, allowing users to search and filter by SEO metrics, backlink profiles, and brand potential without direct registration. The platform connects users to external registrars like GoDaddy to complete purchases.
1 investor
A company developing wearable devices combined with artificial intelligence to detect early signs of sepsis in patients outside hospital settings.
1 investor
SharpestMinds operates a mentorship network where experienced engineers from major tech companies guide aspiring data scientists, with compensation structured as a percentage of the mentee's first-year salary after employment.
1 investor
Shogun provides software tools for ecommerce store optimization and management, integrating with platforms like Shopify and BigCommerce. The product is designed to help merchants build and optimize their online stores through an intuitive interface.
2 investors
Shone retrofits existing cargo ships with autonomous systems to enable unmanned operation.
1 investor
Simetrik provides AI-powered automation software for financial operations, specifically reconciliation and transaction matching across payment processors and platforms. The platform serves finance teams at large enterprises to manage complex transactional landscapes and generate audit-ready reporting.
5 investors
Sixfold develops RNA delivery technology for the biotech industry. The company was founded by an oncologist and plant scientist and focuses on advancing RNA-based therapeutic approaches through proprietary delivery methods.
2 investors
Sketchbox provides a platform for building and deploying VR training simulations, serving large enterprises with built-in analytics and visual editors that require no coding. The company's training applications run on portable, battery-powered VR headsets.
1 investor
Skip operates a fleet of shared electric scooters for last-mile urban transportation, partnering with cities and providing riders with safety training and customer support.
2 investors
Slite provides a knowledge base platform designed for team collaboration and information organization. In 2025, the company expanded into AI-powered search and workflow automation through its Super product.
1 investor
Snackpass is an all-in-one point-of-sale and restaurant management platform that enables restaurants to accept orders through kiosks, mobile apps, and tablets while managing kitchen operations, loyalty programs, and delivery. The platform serves restaurants of all sizes, from independent shops to national franchises, with integrated tools for ordering, payment processing, and customer engagement.
8 investors
Sourcify is a product sourcing education platform that teaches founders and enterprises how to scale their supply chains and bring products to market. The company offers training, workshops, and guidance for product sourcing and manufacturing.
3 investors
Spellbrush is a platform for generating anime and portrait artwork using AI. The service produces magic-themed illustrations and character images for creative and entertainment purposes.
2 investors
Sqreen provides runtime application security monitoring for enterprises, analyzing code execution in real time to protect applications, APIs, and microservices from attacks while maintaining performance.
2 investors
SquadApp is a platform that helps people connect with friends, family, and collaborators in real-time to reduce loneliness and isolation. The app serves individuals seeking meaningful social interactions and personal growth through digital connection.
3 investors
SRTX develops materials and software tools for textile manufacturing, with an initial product line of hosiery made from high-strength polymers.
2 investors
Station is a browser extension that serves as a unified workspace for teams, aggregating content from multiple applications, documents, and messaging platforms while automatically linking related information across them.
1 investor
Substack is a publishing platform that allows writers to create newsletters, cultivate audiences, and earn revenue through reader subscriptions.
6 investors
SuperApp is a mobile shopping platform that enables users to browse, purchase, and receive deliveries through a single app. It operates as a marketplace offering shopping promotions and discounts across East Java.
1 investor