Selling secondhand clothes and accessories online is a booming business, and that’s creating an opportunity for the behind-the-scenes tech players that power the transactions. These include startups such as Trove, Archive, Recurate and The Archivist.

These re-commerce startups are following in the footsteps of Shopify, which grew into a $100 billion market-cap company by helping retailers sell directly to customers online. A new breed of software startups, profiled below, helps brands and vintage stores build sites, manage inventory and make the checkout process more seamless. Altogether, re-commerce software firms attracted $127 million in equity funding last year, more than in the previous three years of funding combined, CB Insights data shows.