Principal Engineer | Go Enthusiast | Open Source Advocate

I'm a software engineer passionate about understanding how things work at a fundamental level. I specialize in Go, diving deep into its runtime, compiler, memory model, and concurrency primitives to build robust, high-performance systems.

• Principal Engineer @ Ona - Working primarily with Go and TypeScript
• Open Source Contributor - Contributor to projects like Mattermost, Penpot, Taiga, and testcontainers-go
• Conference Speaker - Regular speaker at GoLab, GopherCon UK, FOSDEM, and others, focusing on advanced Go internals
• Book Writer - Author of Modern REST API Development in Go
• Blog Writer - Writing about software internals at internals-for-interns.com

I believe in sharing knowledge with the community. Some of my talks:

• "Deep dive into the select statement" - GoLab 2025
• "Having fun with the go source code" - GoLab 2025 Workshop
• "Deep dive into the sync package" - GopherCon UK 2025
• "Deep dive into a Go binary" - GoLab 2024
• "Understanding the Go Compiler" - GopherCon UK 2023
• "Understanding the Go Runtime" - Golab 2023

While Go is one of my key areas of expertise, I also speak about other topics including memory management, PostgreSQL database internals, and applied generative AI in software development.

• Penpot - Co-creator of this open-source design and prototyping platform
• Taiga - Co-creator of this popular agile project management platform
• Focalboard (now Mattermost Boards) - Co-creator of this project management tool born from a hackathon

• Mattermost - Principal Engineer at the company behind this Open Source project.
• Testcontainers-go - Multiple modules contributions and some fixes.
• Developers Conferences Agenda (developers.events) - Contributed with numerous events and code improvements.

• Blog: internals-for-interns.com
• X (Twitter): @jespinog
• LinkedIn: jesus-espino
• Location: Spain
• Languages: Spanish (native), English (fluent)
• Interests: Open source, software internals, developer tools, knowledge sharing and making complex topics accessible

"The best way to understand a system is to look at its source code. The second best way is to build something with it. I try to do both."