3x founder

Sergey Bunas

Co-Founder at 21st.dev (YC W26)

Co-founder

21st· Winter 2026 🇺🇸 San Francisco, California, United States

in LinkedIn 𝕏 @sergeybunas

2025Co-founder· 21st

Founder · since 2021

Company

21st

Role

Co-Founder

current

Stage

—

no public source

Raised

—

no public source

Based

San Francisco Bay Area

current

Founder / co-founder — the company's markEmployee / research role

Source: LinkedIn work history

Profile coverage5 of 7 · missing posts, contact

21st

UI building blocks for the agentic internet

Winter 2026

Experience

Career

21st
Co-founder
Co-Founder · San Francisco Bay Area · 2025 – Present
2025
Deel
Platform Architect · London Area, United Kingdom · 2022 – 2023
2022
Suggesty
Founder
Founder · London Area, United Kingdom · 2022
2022
Stage
Co-founder
Co-Founder, CTO · 2021 – 2022
2021
Rocketbank
Software Engineer · 2019 – 2021
2019

Bio

CS dropout. Senior Software Engineer at Deel (W19). Built Perplexity before Perplexity (Suggesty, 2022 — #1 Product Hunt, featured in Google's internal newsletter). Solo-built a Figma competitor pre-AI (Stage, 10K users). Cambridge AI hackathon winner (solo)