About Me

Jesús Espino

Hi! I’m Jesús Espino, a software developer passionate about understanding how things work under the hood.

My Background

I’m currently working as a software developer at Ona (formerly Gitpod), a cloud development platform that provides AI-powered software engineering agents and sandboxed development environments for teams. Over the years, I’ve worked with various programming languages and technologies, but my primary focus has been on Go and JavaScript/TypeScript, particularly in web and API development.

My Passion

What drives me is the intersection of two things:

  1. Learning how things work - I love diving deep into the internals of the tools and systems we use every day
  2. Sharing knowledge - Making complex topics accessible and understandable for others

I believe that understanding how systems work internally doesn’t require you to be an expert or have years of low-level programming experience. What you need is someone to guide you through the general concepts—the “how it ticks” part—so you can build a mental model of what’s actually happening.

Conference Speaking

For over 10 years, I’ve been giving talks at conferences about how things work under the hood. I started in the Python community, exploring topics like:

  • The internal representation of built-in Python objects
  • How Python’s garbage collector works
  • The phases of the Python interpreter

Later, I expanded into other communities—Go, PostgreSQL, and beyond—always with the same mission: making complex internals approachable. Some of my talks have covered:

  • Understanding the Go Compiler (lexer, parser, type checker, SSA, code generation)
  • Understanding the Go Runtime (memory management, garbage collection, goroutines)
  • Built-in Go objects and their internal structure
  • Performance optimization tricks

Why This Blog?

I’ve wanted to create this blog for almost 10 years. The challenge was always time and resources. Creating deep-dive content that’s both accurate and approachable takes enormous effort, and between my other responsibilities, I could never dedicate the time needed.

But now, thanks to AI, I can speed up the process significantly. AI helps me research faster, draft clearer explanations, and refine my writing—allowing me to finally share this knowledge the way I’ve always envisioned.

What I Write About

My posts explore topics like:

  • Go compiler and runtime internals
  • PostgreSQL query execution
  • Git internals
  • Linux kernel concepts
  • Python internals
  • Database systems
  • Filesystems

Each post takes a concrete example (like a “hello world” program or a simple SQL query) and walks through what happens internally—step by step, concept by concept.

My Approach

I focus on general concepts and mental models rather than exhaustive implementation details. My goal is to give you those “aha!” moments where suddenly the system makes sense, even if you’ve never touched the source code before.

I write in a conversational, friendly style, assuming you have intermediate programming knowledge but not necessarily deep expertise in the specific topic. I use concrete examples, real source code, and visual diagrams to make complicated internals look simple.

Connect With Me

I’d love to hear from you! You can find me at:

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Thanks for reading!

— Jesús