Y Combinator Winter 2021 (W21) Companies

Text Blaze is a productivity tool that creates text snippets and templates to reduce repetitive typing across web applications. It works as a Chrome extension, macOS app, or Windows app and integrates with Gmail, Google Docs, LinkedIn, Salesforce, and other platforms.

1 investor

The Third Place is a platform that celebrates and connects local makers including family-run restaurants, coffee shops, florists, and independent chefs. It helps local businesses expand their reach and build community connections while preserving neighborhood creative spirit.

4 investors

Tilt operates a bike-sharing network with stations in Indian gated communities, allowing residents to unlock and ride bicycles on demand. The company also runs Tilt Media, an advertising platform that places billboards in high-traffic locations within residential complexes across major Indian cities.

1 investor

Tint operates as both an MGA and a technology provider, offering an AI-native operating system for embedded insurance that handles underwriting, rating, policy management, and claims. It designs and manages embedded insurance programs for platforms and marketplaces in mobility, transportation and logistics, and property management, bringing carriers, compliance, and claims administration.

5 investors

Topkey is an AI-powered financial operating system designed for property managers that automates bill categorization, receipt processing, and financial reporting across properties to streamline accounting operations.

4 investors

Topline Pro provides AI-powered tools to help local service professionals like roofers, landscapers, and contractors get discovered online, manage customer relationships, and grow their businesses. The platform combines website building, lead management, customer messaging, reviews, and payment processing designed specifically for home service small businesses.

6 investors

Tractian provides IoT sensors and AI-powered software for industrial asset condition monitoring and predictive maintenance, helping manufacturers identify equipment failures before they disrupt production.

5 investors

Treinta is a cloud-based business management system that enables small business owners to manage sales, inventory, customers, suppliers, and employees from mobile or web. The platform serves retailers, restaurants, cafés, salons, markets, and service providers across Latin America and select other regions.

6 investors

Trela was a food e-commerce platform in Brazil that curated and delivered quality food products to consumers seeking healthier eating options. The company ceased operations on April 2, 2026, after serving over 100,000 customers.

1 investor

Trendpop is an analytics platform that analyzes billions of short-form video posts to help marketers and creators predict viral trends on social platforms like TikTok. The service is used by record labels, brands, and content creators to optimize their video marketing campaigns.

1 investor

Trestle Biotherapeutics develops bioengineered implantable tissues designed to treat end-stage renal disease, aiming to get patients off dialysis and eventually provide replacement organs. The company uses stem cell biology, biofabrication, and 3D bioprinting technologies to create functional kidney tissue for patients with kidney failure.

1 investor

Triomics builds AI systems for oncology teams that read full patient records and produce structured, auditable outputs for trial matching, visit preparation, and data curation. The company serves oncology clinics, trial matching networks, and quality reporting teams.

3 investors

Triplit provides a database and state management system for web applications that handles data persistence and real-time synchronization across clients.

1 investor

Tupelo is a marketplace and platform for buying and selling businesses, serving business brokers, buyers, and sellers. The platform enables deal flow management, business valuation, NDA signing, and connections between market participants to close transactions.

1 investor

Turing College is an online school that teaches practical technical skills through project-based, expert-supported learning programs designed to prepare students for tech careers. The company serves learners seeking flexible, remote education aligned with employer needs, and operates across multiple countries in the edtech sector.

4 investors

Udhaar provides a mobile app for Pakistani businesses to receive payments via bank transfers and wallets, manage finances including cash flows and inventory, and track business transactions. The platform also enables small merchants to earn commissions by selling mobile recharges, utility bill payments, and digital vouchers.

5 investors

Unfurl operates a shared kitchen facility that allows customers to place a single order across multiple restaurant concepts simultaneously, delivering varied cuisines to households in one trip.

1 investor

Unschool operates a platform connecting Indian college students with online courses in technology, management, and the arts taught by global instructors.

1 investor

unSurvey conducts automated market research interviews using AI, eliminating scheduling delays and delivering findings immediately to researchers and product teams.

1 investor

UPchieve provides free, online tutoring and college counseling to low-income middle and high school students across the United States through a volunteer-powered model. The platform matches students with live coaches in under 5 minutes across 20+ subjects including math, science, humanities, and test preparation.

1 investor

Valink Therapeutics develops bispecific antibody-drug conjugates (ADCs) for therapeutic applications, combining high-throughput discovery, antibody engineering, and medicinal chemistry capabilities.

7 investors

Vapi is a platform for building, deploying, and monitoring voice AI agents at enterprise scale, with APIs and integrations for customer support and inbound communications.

6 investors

Veera develops supplements and wellness products designed specifically for women's biology and hormones, with formulations tested on female physiology. The company focuses on evidence-backed, clean, plant-based products for the women's health market.

1 investor

Vendease is a B2B food and beverage supply marketplace for restaurants, hotels, caterers, and other food service operators in Lagos, Nigeria. The platform offers locked pricing, inventory management, and buy-now-pay-later financing, with orders placed via WhatsApp and same-day or next-day delivery.

5 investors