Y Combinator Summer 2021 (S21) Companies

Level buys loans from early-stage fintech startups in small initial quantities and increases capital access based on performance. The company addresses a gap in venture debt availability for early-stage lending startups that are too new to access traditional non-dilutive financing.

3 investors

Levo provides a treasury management platform that helps startups and small-to-medium businesses in Latin America deploy excess cash through customized investment and operational finance strategies.

2 investors

Levro provides a multicurrency account and payments platform that allows businesses to hold and transact in over 30 currencies at exchange rates significantly lower than traditional banks and money transfer services. The platform serves US and international companies with international customers, distributed payroll, or multi-country vendor payments, and includes features for currency hedging, recipient management, and payment reconciliation.

5 investors

Lightly provides tools for AI teams to manage and curate training data more efficiently. The company focuses on data-centric approaches to improve machine learning model quality.

2 investors

Litnerd is a reading and writing application for children that combines collaborative clubs, gamified challenges, and AI-powered personalized tutoring to help kids develop literacy skills. The platform enables children to create original stories, which the app illustrates and publishes, while integrating curriculum-aligned content and learning tools designed around reading science principles.

2 investors

Liv Labs develops pelvic floor fitness products, including the Pippa® Resistance Spring, designed to improve pelvic floor strength for women. The company serves women seeking accessible, affordable pelvic health solutions outside traditional physical therapy.

1 investor

Lobby operates physical locations where health tourism clinics can collect patient data such as dental scans and health information from international customers, starting with the UK market, to support personalized treatment planning.

1 investor

ShopLocale is a meal delivery service that provides meals made with high-protein, organic natural ingredients, without seed oils and reduced microplastics. The service targets health-conscious consumers seeking science-backed nutrition.

2 investors

LootRush provides a multi-currency account that allows individuals to earn income in one country, reside in another, and access their funds internationally.

3 investors

MejorCDT is a fintech platform that aggregates and compares Certificate of Deposit (CDT) rates from Colombian banks in a single interface, allowing users to invest in government-regulated financial institutions directly without visiting physical branches. The platform earns revenue from banks rather than users and offers flexible withdrawal options for emergencies.

1 investor

Luminate develops medical device technology to address chemotherapy side effects, particularly hair loss and peripheral neuropathy, for oncology patients and healthcare providers. The company is advancing clinical-stage devices while supporting cancer patients, clinicians, and health systems.

6 investors

Mable is a genomics-based telehealth platform that provides personalized migraine care by analyzing patients' genetic and biomarker data to inform individualized treatment plans. The company serves migraine sufferers seeking precision medicine alternatives to traditional trial-and-error medication approaches.

2 investors

Mach9 builds automated feature-extraction software for transportation, telecom, and construction industries, enabling rapid extraction and mapping of large-scale infrastructure projects. The company serves surveyors, transportation agencies, and engineering firms in North America.

2 investors

Mailmodo is a platform that uses AI to help marketers plan, create, and automate email campaigns with interactive elements like forms and polls directly in emails. The service targets email marketers and enables higher engagement and conversion rates through interactive email experiences and AI-powered campaign automation.

3 investors

Makani Science develops a wearable patch sensor that continuously monitors respiratory function wirelessly and noninvasively for patients undergoing sedation, surgery, or managing chronic respiratory conditions. The device tracks respiratory rate, tidal volume, and minute ventilation in real-time via mobile platforms for healthcare professionals.

1 investor

Malga provides a modular payment infrastructure and orchestration platform that enables companies to build customized payment flows with multiple processors and methods integrated in a single system. The platform serves online merchants and enterprises seeking to increase approval rates, reduce fraud, and consolidate payment operations.

4 investors

Malloc is a mobile privacy and security app combining AI-driven spyware detection with a no-log VPN to protect users' data and privacy on Android and iOS devices. The app targets consumers concerned about data tracking, malware, and spyware threats on their smartphones.

3 investors

Marketfeed helps salaried Indians consolidate or refinance multiple loans and credit card debts into a single lower-EMI loan through its network of lending partners. The platform uses AI to analyze eligibility and compares offers from banks and NBFCs to find the lowest interest rates.

3 investors

Maroo is a billing and invoicing platform for freelancers and small service businesses, offering features like automated client invoicing, payment processing, CRM functionality, and 1099 tax form generation.

2 investors

MarqVision provides brand protection and intellectual property management services using AI technology for creators, developers, and artists globally. The platform helps innovators identify and defend against threats to their intellectual property and livelihoods.

4 investors

Matidor provides location-intelligent project management software that combines GIS mapping with field operations coordination for environmental consulting and oil and gas teams. The platform gives field teams and office leaders real-time visibility and control over multi-site work, replacing spreadsheets and disconnected systems.

4 investors

Matrubials develops antimicrobial peptides derived from milk to create novel therapeutics for bacterial infections, starting with bacterial vaginosis. The company uses AI-enabled technology to identify and validate bioactive molecules for infectious disease treatments.

1 investor

Mecho Autotech operates a mobile app and network of verified mechanics and parts suppliers that connects vehicle owners in Africa with maintenance and repair services, offering an alternative to expensive branded garages and unvetted roadside mechanics.</description> </invoke>

4 investors

Medium Bio engineers customized proteins using AI and protein design to create affinity reagents for research teams and diagnostic developers. The company accelerates molecular tool development from design to experimental validation within weeks.

2 investors