
How to build a dev tool with zero marketing with Sergiy Korolov @Mailtrap
From saas.unbound by Anna Nadeina
March 9, 2026 · 55 min · Season 6 · Episode 10
About this episode
In this episode, Anna Nadeina interviews Sergiy Korolov about building Mailtrap with zero marketing and the lessons learned from his entrepreneurial journey.
saas.unbound is a podcast for and about founders who are working on scaling inspiring products that people love, brought to you by https://saas.group/ , a serial acquirer of B2B SaaS companies. In episode #10 of season 6, Anna Nadeina talks with Sergiy Korolov, co-founder of Railsware and the brain behind Mailtrap. From accidentally launching one of the most popular developer tools with zero marketing budget, to running the company with an all-engineer team — Sergiy's journey is packed with lessons most founders learn the hard way. In this episode: → How Mailtrap grew to hundreds of thousands of users before charging a cent → The "product studio" model Railsware uses to co-found new companies → Why bootstrapping forces better decisions than VC money → The hard truth about vibe coding and AI's real impact on engineering teams → How to hire when you don't know enough to assess the role → Why your biggest job as CEO is to stop having sleepless nights ----------- Episode's Chapters ----------- 0:05 — Introduction & Product Overview 0:27 — Background & Early Days of Railsware 3:51 — Building Product Studio Culture 6:58 — Creating Mailtrap - From Tool to Platform 14:10 —…
People in this episode
Host: Anna Nadeina
Guest: Sergiy Korolov
Topics covered
- developer tools
- bootstrapping
- product development
- team building
- AI integration
- founder experiences
Keywords
- Mailtrap
- Railsware
- bootstrapping
- developer tools
- AI in engineering
- hiring strategy
- product studio
Sponsors
saas.group
Mentioned in this episode
Organizations: Mailtrap, Railsware
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