Meet 23 companies that recently announced they’re part of the YC Winter 2019 batch. To see more YC W19 companies read Part 1, Part 2, Part 3 and Part 4.

WeatherCheck monitors properties for severe weather damage so that insurance carriers, mortgage companies, and property owners can take action. Each year, hailstorms across North America cause more than $10 billion in damage. But because the damage is often not discovered until months or years after an event, mitigation and repair costs escalate. WeatherCheck provides clarity in the midst of dynamic and constantly evolving severe weather conditions, specifically in the 24 hours before and after an event when information is most limited. WeatherCheck currently monitors 2.7 million structures. WeatherCheck was founded by Demetrius Gray and Jermaine Watkins. Gray previously owned the largest minority owned roofing company in the U.S. Watkins was a developer at YUM Brands.

Alpaca is an API-first brokerage for high volume algorithmic stock traders. Alpaca built a FINRA approved securities broker that provides a commission-free stock trading API. It’s built for developers and the small quant funds who do high volume trades with their algorithms. Since Alpaca launched last October, transaction volume has grown 2X every month, and it has processed $25 million dollars and 7 million API calls. The company has recently brought on the ex-CCO of WealthFront and co-founder/CTO of Greenplum to help the business scale.

Truora does fast, reliable background checks in Latin America through an online platform; they’re like Checkr for LatAm. In less than 20 seconds, Truora’s clients can access criminal, legal and driving records, as well as domestic and international government lists (criminal, identity fraud, money laundering). They’re currently working with the region’s top marketplaces, HR teams and financial institutions to optimize onboarding and reduce their risk.

Thrive Agric provides microloans to Nigerian farmers and a channel to sell produce to large buyers. Nigeria has over 32 million small farmers. Most of them are unbanked and capital constrained. Thrive Agric created a marketplace where urban Nigerians make $200 loans to farmers, and earn 10-15% interest in the process. In February, Thrive Agric funded these farmers with over $500k in loans, with a monthly growth rate of about 50%. Thrive makes farmers much more efficient with access to financing, agricultural best practices and a premium market for their products.

Heart Aerospace is an electric aircraft startup that builds electric passenger aircraft for regional transport, with an early focus on the Scandinavian market. The Swedish government has mandated that all domestic air travel be fossil-fuel free by 2030, and Norway that all domestic air travel be electric by 2040. Heart is building the product to meet this need. Heart’s first aircraft ES-19 will take 19 passengers and have an operating range of 250 miles on batteries, enough to cover a third of domestic traffic in Sweden, and 14 percent of departures worldwide. The aircraft will be carrying its first commercial passengers in 2025. Heart has the support of the Swedish Government, the Civil Aviation Administration and the airport organizations of Sweden and Norway. The Swedish airlines SAS and BRA, as well as the Norwegian airline Widerøe, have already signed letters of interest for 86 planes, at a value of $1.6B dollars.

Geosite uses spatial data to enable rapid and accurate planning and operations. Their customers include the U.S. military and companies in the energy industry. The platform leverages the proliferation in satellite imagery sources and distributed sensor systems. Recently, Geosite’s founder, Rachel Olney, was accepted to pitch at the inaugural Air Force Pitch Day and has a Cooperative Research and Development Agreement (CRADA) with Special Operations Command.

Community Phone is an affordable cell phone carrier. Community Phone provides better plans and services by aggregating hundreds of cell phone networks to offer inexpensive plans. The company is announcing a new partnership with Neblazr, Boston’s independent internet provider, to launch the first no contract alternative to Xfinity Mobile.

AccioJob is a college job board in India where universities sign up to expose their students to the best companies. They eliminate the need for companies to physically visit campuses for hiring. This saves companies time, money and lets them hire better talent from a larger pool of applicants. On the student side, most students in India are forced to choose from a handful of job options from local companies that visit their campus. AccioJob is building this platform to enable students from all colleges to have a fairer shot at any company they wish to apply to.

Memfault helps hardware companies catch and fix embedded software bugs. Unlike mobile or web developers, hardware engineers today do not find out something is wrong with their device until their customers start calling (or worse, tweeting). Memfault gives companies the initiative by providing a real time view of errors their devices are encountering in the field, and infrastructure to deploy targeted fixes. Memfault is built by ex-Fitbit, Pebble, and Oculus engineers who know the industry well and have been wrestling with these problems for 15+ years.

Atomic Alchemy manufactures nuclear medicine, which is used for diagnostic imaging and cancer treatment. Five of six government-run reactors, which produce nearly the entire world’s supply of nuclear medicine, will shut down by 2030. Atomic Alchemy will fill the gap to ensure the stability of the nuclear medicine supply by building several compact reactors that are 15x more powerful than reactors typically found at a university.

AXDRAFT provides free legal documents for startups in minutes. Startups don’t need a 20-page contract in 2 weeks, they need simple, balanced contracts now, to close deals quickly. Founders can get a contract from AXDRAFT in minutes by answering just a few simple questions. In the week since they launched, AXDRAFT has created 332 contracts and got over 1,400 upvotes on Product Hunt.

Verto is building a currency exchange marketplace that gives African businesses access to foreign currencies and lets them make international payments. Verto was developed to solve a problem faced by its founders who are both ex-bankers with a combined 20 years of treasury, regulatory and payments experience. African companies often need to make payments for goods and services abroad with foreign currencies, but the process is fraught with challenges. African business often encounter issues with liquidity, long payment settlement periods and high transaction fees. Verto solves these problems by allowing customers to swap currencies at a price determined by them, quickly and securely. Using a marketplace model and algorithm, Verto can identify market demands, and provide price discovery and liquidity for frontier market currencies. They are currently launched in Nigeria.

Trestle is the source of truth for company information. At fast growing companies, it’s challenging for people to understand who they’re working with, figure out where to get help, or to keep up to date with what’s going on in the organization. Trestle solves this by providing a great intranet that includes company announcements, people search, customizable employee profiles, and team interfaces to share updates and information.

Seawise Capital is a trade finance company for Indian exporters. They provide SMEs working capital against the strength of their international customers. Every year, banks reject $50bn of trade finance requests due to failure to provide 100% collateral. Seawise Capital is able to provide these businesses with collateral-free capital by discounting invoices from their large overseas customers. In addition, they track over 1,000 data points for every exporter to minimize operational risk.

AI Insurance builds claims management software for small insurance companies. By introducing digital workflows and predictive analytics into a 300-year-old space, AI Insurance is changing how claims are handled. They put the tools of the big companies in the hands of the small ones so that claims close faster, insureds get paid faster, and insurers save money.

ExcepGen is the only company able to quickly produce a large number of complex human proteins. Pharmaceutical companies need these proteins for drug development, and every ExcepGen protein can save them months of development time and millions in costs; the protein could also prevent multi-billion dollar drug failures caused by inaccurate hit identification. Today, ExcepGen is working with 3 of the top 15 pharmaceutical companies. Read more about ExceptGen in FierceBiotech.

YSplit makes virtual debit cards for group payments that automatically charges everyone for their share. By connecting bank accounts to YSplit, roommates can easily split utility payments on a recurring basis, for example. The founders of YSplit saw first hand the inefficiency of one person fronting the bill, then requesting payments from the group every month. Over the next few months, thousands of YSplit cards will be released to make it simple to share bills. Read more about YSplit on TechCrunch.

YourChoice Therapeutics is developing non-hormonal contraceptives for women and men. Their first product will be a vaginal contraceptive to be applied before intercourse followed by oral contraceptives that can be taken by men and women. These products are based on blocking a protein on sperm that is required for fertilization. YourChoice Therapeutics’ non-hormonal approach does not interfere with either a cells’ ability to function or gene expression, so women and men will not experience negative side-effects associated with traditional hormonal contraceptives, such as blood clots or cancer. Read more about YourChoice in TechCrunch.

Pachama is a verified marketplace for carbon offsets — solving climate change by restoring forests. They use high-definition, high-frequency satellite images to estimate carbon storage in forests and predict future deforestation or potential for forest restoration. Read more about Pachama in Fast Company.

Shiok Meats is a cell-based clean meat company making shrimp and crab. Their products are animal-, health-, and environment-friendly without sacrificing taste or texture. To create their clean meat, Shiok Meats harvests cells instead of animals. Shiok Meats is the first cell-based meat company in Southeast Asia and at Y Combinator. You can read more about Shiok Meats in Tech in Asia.

Spiral Genetics makes genomic data mining software to compare large populations of whole human genomes — ultimately, to compare genomes at scale and power novel discoveries that lead to new diagnostics and drug discovery. Spiral Genetics partnered with Microsoft to create one of the first applications of machine learning to make phenotype predictions based on large genetic “structural variations”. The initial application will be the prediction of cardiovascular disease based on a person’s genetics. SpiralGenetics is also being used by governments, pharmaceutical companies, and large academic research institutions. Spiral Genetics’ CEO, Adina Mangubat was featured in 2013 “Forbes 30 Under 30: The Rising Stars Transforming Science and Healthcare – The Real Future of Biotech” and 2018 Forbes 30 Under 30 All Star Alumni. Read more about Spiral Genetics in Forbes.

Adventurous is a mobile app that lets families go on augmented reality adventures through their city while interacting with live actors. Rather than another game for kids to stay indoors and play, Adventurous gets kids outside to explore the neighborhood and is an experience the entire family can do together. Adventurous brings the imagination of theme parks directly to the neighborhood at a fraction of the cost. Adventures are currently available in San Francisco Bay Area with new locations coming soon. Read more about Adventurous in TechCrunch.

Aura Vision is Google Analytics for offline shops. They use video from existing store security cameras and combine it with computer vision to detect the demographics of people entering a shop, and what they do once inside. Many retailers currently make costly, wide-ranging decisions, based on assumptions and guesswork. Aura Vision provides insights into what shoppers actually do, so retailers can work out why certain products are underselling, and how to increase footfall. Recently, a client was able to increase footfall to all stores 9%, by A/B testing different window displays and tracking the change in peel-off rate. The founding team includes two Computer Vision PhDs. Read more about Aura Vision in TechCrunch.