hi, i’m sergey bunas

software engineer/startup guy.

proficiant with typescript/fullstack/0 to 1.

love to study ai/ml/chip design in my free time.

based in London, UK.

Facts

• 8 years of software engineering experience.
  ex: deel(YC19)/rocketbank/X5
• solo won 1st place at Cambridge University’s AI hackathon
• got into Entrepreneur First London startup incubator
• got featured in the internal Google’s newsletter

Work & Projects

21st.dev - Open-Source UI components & MCP [2025]

Built an open-source platform for AI-assisted React UI development. Built MCP Magic Extension, extending Cursor IDE capabilities. 3K+ users on the waitlist in 3 days.

Entrepreneur First - Top startup incubator in London [2024]

Selected among the top 0.7% from 10,000+ global applicants. Validated multiple tech venture concepts through talking to users and rapid prototyping. Successfully navigated co-founder matchmaking, investor pitches, and product development cycles.

Monolith - AI cold outreach [2023-2024]

First engineer at Monolith, a startup replacing cold outreach with AI. Built the tech from scratch, hiring a team, and developing advanced GenAI pipelines. Raised $2M and reached $120k ARR in 4 months.

Deel - Global HR & tax automation [2022-2023]

Senior Full-Stack Engineer at Deel, the fastest-growing startup in the world ($12B valuation in 2023). Led tax features, including integrating Sorted, an acquired tax automation startup. Built a tax consultant marketplace and optimized backend workflows.

Replai: AI replies for social media. [2022-2023]

Founded Replai, an AI tool for generating responses on X/LinkedIn. Launched the MVP in 5 hours, posted on Twitter & vent viral, got paying users in 3 days, and hit $1k MRR in the first month. Ranked #3 on Product Hunt.

Suggesty: GPT-3 for Google search [2022].

Before ChatGPT hype, created Suggesty, a Chrome extension that generates AI-powered answers in Google search. Reached 3k users in the first week and got #1 Product of the Day on Product Hunt.

Got featured in the internal Google’s newsletter.

Stage: No-code UI/UX tool [2021-2022].

Co-founded Stage, a UI/UX tool for non-designers. Implemented real-time collaboration and a component-based design system. Over 10,000 users, 13k+ projects created.

X5 Retail Group: powered logistics [2019-2021]

Lead frontend developer at Eastern Europe’s largest grocery retailer (19,776+ stores). Built an AI-optimized logistics system managing 50,000+ employees, replacing legacy SAP solutions. Created a unified UI component library improving consistency and reducing development effort.

Rocketbank: Innovative fintech interfaces [2017-2019]

Software developer at innovative fintech startup acquired by Qiwi. Won a code challenge for the best banking app UI, implemented Server-Driven UI to streamline interface development, enhancing productivity for 400+ internal users.