Y Combinator Winter 2021 (W21) Companies

R2 provides embedded financing solutions for merchants, enabling platforms to offer credit through seamless API integration with AI-driven risk assessment and same-day funding.

5 investors

Reclaim Protocol provides automated credential verification across employment, education, loyalty, and other categories using AI-assisted connectors and cryptographic verification. The platform serves enterprises and platforms that need to verify credentials across 90+ countries at significantly lower cost than legacy verification providers.

2 investors

Recover provides evidence-based addiction treatment using technology and clinical care to help patients find recovery. The company delivers care to individuals struggling with substance use disorders, leveraging data-driven insights and partnerships with local providers.

2 investors

Redcliffe Labs is a diagnostic laboratory platform in India offering at-home and lab-based health tests with personalized health packages, AI-powered report analysis, expert consultations, and genomic testing services. The company targets consumers seeking affordable, accurate diagnostics with personalized health guidance and family-focused healthcare solutions.

10 investors

REGENT designs and manufactures Seaglider wing-in-ground-effect aircraft for regional coastal transportation and defense logistics, offering high-speed zero-emission travel between coastal cities and military applications.

17 investors

Rejoy Health builds AI-powered tools for healthcare providers including clinical documentation, patient communication, and diagnostic support. The platform serves doctors, clinics, and healthcare teams with HIPAA-compliant features for charting, scheduling, interpretation, and evidence-based clinical guidance.

1 investor

Remora Carbon provides strategic advisory services to transportation, logistics, infrastructure, and geospatial sectors, with focus on transformational technologies. The company serves technology startups, transportation carriers, and infrastructure/private equity investment funds.

7 investors

Reshape provides an AI-driven operating system that automates microbiology data capture and analysis for research laboratories. The platform structures experimental results and surfaces insights to help lab teams accelerate research and product development.

4 investors

Resquared is an AI outbound sales platform that helps businesses reach local brick-and-mortar establishments using a database of 14M+ verified local businesses, AI-powered personalized outreach, and built-in email delivery. The platform serves sales teams, brokers, agencies, and SaaS companies selling to Main Street businesses across various industries.

2 investors

Rethoric is a LinkedIn content and growth agency that helps founders and executives build thought leadership through ghostwritten posts and strategic engagement. The service targets Series A+ founders at high-growth tech startups, combining bi-weekly founder interviews and human-written content to generate LinkedIn impressions and inbound business.

3 investors

Rinsed is a CRM and business management platform for car wash operators that integrates with POS systems to manage memberships, customer retention, and sales operations. The platform includes tools for membership sales, churn reduction, sales analytics, and AI-powered customer support.

1 investor

RocketSDR develops AI-powered software to automate and enhance sales development tasks, helping sales teams reduce repetitive work and improve prospect engagement.

1 investor

ROGER is an electronic signature platform that helps startups, small businesses, and growing teams send contracts and collect legally binding digital signatures. It offers contract management features including templates, approval workflows, centralized document storage, and compliance with ESIGN Act and UETA standards.

1 investor

Roin Technologies makes robots that automate the pouring and finishing of concrete floors on construction sites, allowing a single operator to complete work that traditionally requires multiple workers.

1 investor

Routine builds an AI-powered work platform that integrates and centralizes data from third-party services like GitHub, Salesforce, Slack, and Dropbox into a unified workspace for project tracking and team collaboration. The platform uses a graph-based approach to connect fragmented information across tools, serving teams and individuals who want a consolidated view of their work without constant app-switching.

5 investors

Rulebricks provides a no-code decision management platform that allows teams to model, publish, and manage business decision logic through API endpoints. The platform serves enterprises across industries needing to automate decisions like approvals, fraud detection, routing, and eligibility calculations.

1 investor

Runway provides a platform for managing and orchestrating mobile app releases. The service helps mobile development teams streamline the process of shipping apps to millions of users.

4 investors

SBX Robotics creates synthetic training images for robot computer vision systems using simulation, enabling companies to generate large labeled datasets from minimal seed imagery at a fraction of traditional annotation costs.

1 investor

Seer provides a platform for sales associates in luxury retail to create and share customized lookbooks and style recommendations with clients. The tool replaces manual processes like image curation and email recommendations with an integrated application designed for in-store and online sales teams.

3 investors

Segments.ai provides a multi-sensor labeling platform for robotics and automotive companies. The platform is used for data annotation and labeling in autonomous vehicle and robotics development.

3 investors

Sendbox is a logistics and delivery platform that enables local and international shipping for e-commerce sellers, social commerce merchants, and individuals. The platform provides payment processing, delivery services, and a marketplace infrastructure for retailers, brands, couriers, and platform operators.

7 investors

Serna builds a platform to unlock the transcriptome as a drug target for drug discovery. The company integrates technology and biology to change drug discovery processes.

4 investors

Shepherd combines underwriting expertise with technology to modernize commercial insurance risk selection, pricing, and servicing.

2 investors

SigNoz provides observability and monitoring tools that help DevOps engineers and developers reduce noise and extract actionable signals from their systems. The platform serves engineering teams working with microservices and distributed systems.

2 investors