21st

Top 12 DevTech · YC Winter 2026

UI building blocks for the agentic internet

View on Y Combinator

Founders

Serafim Korablev

CEO

Sergey Bunas

CTO

Funding History

YC W26

January 2026

Y Combinator, Pioneer Fund

Articles

The Top 12 DevTech Startups in YC W26

The Top 12 DevTech Startups in YC W26

Mar 18, 2026 · DevTech

From AI agents infrastructure to self-healing CI pipelines, here are the standout developer tools companies from Y Combinator's Winter 2026 batch.

21st Builds the Production Layer for AI Agents

21st Builds the Production Layer for AI Agents

Mar 16, 2026 · DevTech

21st.dev, the React component registry used by 1.4M developers, is launching an SDK that handles the infrastructure needed to ship frontier AI agents like Claude Code inside production applications.