Tandem is an AI-native office leasing marketplace and broker that helps companies discover, lease, and share office space. The platform connects companies seeking flexible office space with landlords and hosts listing excess space, using AI-powered workflows that reduce lease transaction times from the typical three to six months to 14 days or less. Tandem primarily serves tech companies and hybrid teams in markets such as New York, San Francisco, and Los Angeles, and says it has helped over 300 companies find and share office space. Emerging from Y Combinator's Summer 2024 batch, Tandem announced $6.1M in seed funding in February 2025 led by Collide Capital, 1984 Ventures, and Y Combinator, with angels including Stanford economist Nick Bloom.