How to build a dev tool with zero marketing with Sergiy Korolov @Mailtrap

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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