Top Series B companies in the United States
Companies that have closed a Series B - proven scaling motion, hiring aggressively. Filtered to companies headquartered in the United States.
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- StageSeries B
- HQthe United States
- Matches3,704
Built from a search like: “Top Series B companies in the United States”
Ranked by current headcount across Series B companies headquartered in the United States. Refreshed monthly.
- 1Railway· San Francisco, California, United States
Railway’s mission is to build the cloud computing stack that unburdens you, so you can focus more on what matters to you.
- Series B
- 11.4k employees
- Founded 2020
- 2Grammarly· San Francisco, California, United States
Grammarly stands with Ukraine. We invite you to do the same. Here are some ways you can help: gram.ly/WeStandWithUkraine ---Grammarly is the world’s leading AI writing assistance company trusted by over 40 million people and 50,000 organizations every day. From instantly creating a first draft to perfecting every message, Grammarly helps people at 96% of the Fortune 500 get their point across—and get results—without compromising security or privacy. We believe that great writing gets work done. Grammarly’s product offerings—Grammarly Business, Grammarly Premium, Grammarly Free, and Grammarly for Education—work where you do, delivering contextually relevant writing support across over 500,000 apps and websites. Founded in 2009, Grammarly is No. 7 on the Forbes Cloud 100, one of TIME’s 100 Most Influential Companies, one of Fast Company’s Most Innovative Companies in AI, and one of Inc.’s Best Workplaces. Grammarly offers a dynamic hybrid working model. This approach helps foster trust, innovation, and a strong team culture, with the flexibility of working from home, whenever you need focus time.
- Series B
- 9.8k employees
- Founded 2009
- 3Calendly· Atlanta, Georgia, United States
Calendly connects the entire meeting workflow — scheduling, payments, meeting notes, follow-ups, contacts, and more — and handles the work before, during, and after meetings. From solo business owners to teams within large organizations, more than 50 million people across 240+ countries trust Calendly to help them get more out of every meeting.If you're thinking about joining us, we want the people who build Calendly to experience the same value our customers do. You'll own tangible work, see it reach real customers, and grow through the challenges that come with building something meaningful. We're remote-first, guided by strong values, working alongside people who care about the work and each other.
- Series B
- 9.4k employees
- Founded 2013
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- 4Chief· New York, New York, United States
Chief is a community of ambitious women executives shaping the new era of leadership.Chief exists to create more possibilities for women’s power.Today’s leaders face seismic shifts unlike any generation before them. But they don’t have to do it alone. Networking is not just a necessity, it’s a door to unique possibilities. Our members catalyze their ambition with the tools, the network, and the space to do business, create change, and lead on. We believe that women are as ambitious as ever.We believe that leadership today is non-linear.We believe that connections between powerful women unlock possibilities. We believe that multihyphenate women are rewriting the rules of leadership for the next generation. Our strength lies in our diversity. Each new perspective grows our collective power.Chief is the only membership network that combines access to exclusive Clubhouses, world-renowned Guides and Executive Coaches, top-level training from the Wharton School of Business, annual summits, and events at the industry conferences that matter.Apply today: chief.com/apply
- Series B
- 7.6k employees
- Founded 2019
- 5Outlier AI· Oakland, California, United States
Outlier shut down in 2022, this page remains as a memory of our company and on the resumes of our team.Business intelligence is ready for a change. We don't believe the world needs any more dashboards, charts or data warehouses. What leaders need today is help to make better use of the tools they already have. That is what we do at Outlier: we improve the relationship between people and their data.We believe that success in life and success in business are not separate things, but intertwined as part of our lives. It is important to us that the journey we take with our company is as positive as the destination we hope to reach.
- Series B
- 7.3k employees
- Founded 2015
Find engineers at Series B companies in the United States
Series B companies in the United States are some of the fastest-moving employers in the market. The list above ranks the largest Series B-stage companies headquartered in the United States by current headcount, drawn from public LinkedIn and Crunchbase records. With 3,704 matching companies in Refolk’s index, the density of senior engineers, designers, and founders is unusually high.
At Series B, teams tend to be small, ambitious, and on the hunt for senior talent. The companies on this list are good signals for where the the United States talent market is heating up - and for which engineers and founders are about to become tomorrow’s operators.
Refolk converts this list into a live search. Ask for “founders of Series B companies in the United States” or “senior engineers at Series B companies in the United States hiring” and Refolk returns a ranked shortlist with evidence behind each match.
How this list is built
Last refreshed: Mon, 21 Sep 2026 13:38:20 GMT
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How is this ranking built?
The list draws on the public company graph - headcount and growth signals, funding history, and recency. The criteria chips at the top show exactly which filters produced it, and the methodology section explains the ranking.
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The underlying index updates continuously and this ranking is rebuilt monthly. Last refreshed: Mon, 21 Sep 2026 13:38:20 GMT. For a list built against the index as it stands today, sign up and run the search live.
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