Resend

📌 Snapshot: 1-1000 · Email API for developers · Founded by Brazilian open-source developers, SF-based · First customer Sep 2022 → public launch Jan 4, 2023 (6,338-person waitlist in 7 weeks) → 1,000 paying customers Dec 2023 → 100K users Apr 2024 → 1M users Dec 2025 → 3M users Jun 2026 (company blog).

Problem statement

Transactional email was dominated by old platforms with HTML-era tooling and deliverability anxiety. Resend's angle: a developer-first email API, with emails written in React instead of fragile HTML tables.

GTM stack & growth engine

• Open source first. React Email (the open-source templating library) came before the paid sending platform and drew developer attention; the paid API monetised it.
• Founder audience. Zeno Rocha had built ~39K followers on X over years of posting about his open-source work. The launch tweet (Jan 4, 2023, posted 7am PT on a Wednesday, with video) passed ~1M views, plus ~107K views on LinkedIn.
• Brand as differentiation. A minimal landing page with an animated object and keyboard shortcuts, signalling care for developer details. He spent $25K on the resend.com domain and wrote publicly about why.
• Waitlist qualification. A Typeform segmented the waitlist; mandatory onboarding calls were dropped for auto-onboarding certain segments once volume grew.
• Generous free tier (June 2023), then a Scale plan (Oct 2024).

Content loops

• Launch weeks (first in Mar 2023, then "Resend Forward"): seven features in seven days, each a reason to post, then a wrap-up post.
• Public handbook and dated timeline ("How we got here") plus milestone posts (100K, 1M, 3M users) that double as social proof.
• Customer engineering stories (Gumroad, Raycast, Vercel, Replit, Dub) and deliverability guides that rank in search.
• Welcome posts for every new hire, so the team itself becomes content.

Distribution system

• Platform integrations put Resend inside the default stack: Vercel, Supabase, Next.js examples.
• Community events (Resend Forward conference, Hacktoberfest, an MCP hackathon) and "Clubs".
• Founder-led social, then later the first account executives (2026).

AI angle

Resend wrote early about "agent experience" (AX): making docs, CLIs, templates and skills easy for AI coding agents to use, so agents pick Resend when they assemble a stack. It also shipped an MCP server, email skills, an AI email editor and new.email (an AI email builder, later sunset).

Key people & public artefacts

• Zeno Rocha (founder, CEO): X @zenorocha, the Resend blog and handbook.
• Bu Kinoshita (co-founder, CTO).
• Jonni Lundy (operations and deliverability; customer stories).

Key insights

• Steal: Ship an open-source tool that solves the annoying half of the problem; sell the hard half.
• Steal: Make launch weeks a recurring media format; each feature gets its own day and its own post.
• Steal: Qualify your waitlist with a short form and onboard by segment, rather than first-come-first-served.
• Avoid: Their own post-mortem says to load-test the landing page on real phones and validate waitlist emails before launch day.

Sources

• Resend handbook: How we got here
• Resend: Lessons learned from growing a 6,338 people waitlist in 7 weeks
• Resend: What is AX (Agent Experience)
• Resend blog index (milestones, launch weeks)