Y Combinator Winter 2025 (W25) Companies

Rebolt generates autonomous software that automates core business operations across manufacturing, construction, architecture, automotive, and media by connecting business objects and processes into a live operating model. The platform creates AI-powered automation for workflows like quote-to-production, field-to-finance, and project management with built-in approvals and governance.

1 investor

Red Barn Robotics develops autonomous weeding robots for farms to eliminate intra-row weeds without human intervention, reducing labor costs and protecting soil health. The company offers a service model where it maps fields, schedules custom weeding plans, and deploys robots throughout the growing season.

3 investors

Reditus Space builds reusable spacecraft systems that enable routine return of cargo from low Earth orbit, supporting in-space manufacturing and physical industrialization of space. The company provides infrastructure for commercial operators and manufacturers to deliver products and materials back to Earth economically.

5 investors

ReJot is an open-source software development platform or toolkit. The page provides limited concrete details about its specific offerings or target customers.

1 investor

Retrofit operates a secondhand clothing marketplace where algorithmic curation helps match buyers with vintage items based on their style preferences, measurements, and spending limits.

1 investor

Revise Robotics builds robotic systems with AI that automate the assessment and refurbishment of discarded electronics for recycling facilities and second-hand resellers. The system tests devices, erases data, photographs units, and lists them for resale across multiple operating systems and manufacturers.

5 investors

Riviera provides an AI voice and messaging agent for hotels that answers calls, handles texts and emails, manages reservations, and routes complex requests to staff. It serves independent hotels, full-service hotels, and hotel groups across multiple languages and guest channels.

1 investor

Roark builds a quality testing platform for voice AI agents using audio-based evaluation models. The platform allows teams to simulate calls before launch, score production conversations on audio, and validate fixes before customer deployment in healthcare, finance, insurance and other regulated industries.

1 investor

Rocketable acquires software businesses and automates their operations by replacing human staff with AI agents across functions; the company develops tools to coordinate these agents toward shared business objectives.

2 investors

SalesPatriot builds an AI operating system for procurement and distribution in defense, aerospace, and industrial sectors, automating complex supply chain workflows that currently rely on fragmented systems and manual processes.

3 investors

SAMMY AI compiles regulatory statutes, case law, and a company's own procedures into deterministic, code-based legal engines that audit accounts, block non-compliant actions, and file regulator-ready reports via a platform or API. It offers real-time compliance for operational actions, AI voice agents, and customer communications, plus automatic policy updates and cross-jurisdiction horizon scanning for regulated businesses.

1 investor

Scout for Schools provides enrollment automation software for schools, using AI to extract and verify student documents and streamline the onboarding process. The platform offers guided enrollment flows, smart forms, and automated reminders to reduce enrollment time from weeks to days.

1 investor

Sennu AI develops AI systems designed to reshape business operations for traditional enterprises.

1 investor

Solidroad provides quality assurance and training software for enterprise customer experience teams, using AI to unify and continuously improve performance across human and automated agents across multiple communication channels.

4 investors

Splash9 manufactures autonomous surface vessels (ASVs) for maritime applications including coastal defense, harbor patrols, seabed mapping, and infrastructure security. The company builds scalable drone-boats with autonomous navigation, long-range capability, and multi-mission payload flexibility for government, military, and commercial customers.

3 investors

Spott builds an ATS and CRM platform for recruitment agencies that integrates AI directly into its core infrastructure. The platform aims to streamline candidate matching, outreach, and administration for professional recruiters through practical AI features.

1 investor

Stamp is an AI email assistant that learns user preferences to automatically draft, prioritize, categorize, and schedule emails. It serves professionals seeking to automate email management and inbox organization through personalized AI.

1 investor

Steinmetz designs and manufactures high-voltage motor controllers and traction inverters for electric vehicles, industrial automation, and robotics. The company produces power electronics with industry-leading power density and efficiency for EV drivetrains and motor control systems.

3 investors

Stillwind develops an AI-powered search engine that converts natural language queries into electronic component specifications, matching them against a proprietary database of millions of parts. The company is building toward a broader platform for autonomous electrical engineering, targeting embedded systems engineers and hardware developers.

1 investor

SubImage maps cloud, SaaS, and on-prem infrastructure into a single graph to show security teams what is exposed, misconfigured, and needs fixing first. It offers a managed CNAPP built on the open-source Cartography security graph, connecting via a read-only agentless API and integrating with SIEM, SOAR, and ticketing systems.

2 investors

A desktop application that tracks team productivity and helps groups maintain focus on product development and delivery.

1 investor

Subtrace is a tool that captures and displays HTTP traffic to and from running processes in real time without requiring code modifications or elevated permissions. It serves infrastructure engineers and developers who need visibility into network activity across their systems.

3 investors

Superglue provides AI agents that automate enterprise system integration, data migration, and implementation work across cloud or on-premises infrastructure. The platform connects disparate systems and performs data synchronization tasks that typically require manual engineering coordination.

2 investors

Swerve is an iOS app that enables users to chat with AI characters. The platform serves consumers interested in conversational AI interactions.

1 investor