About

I'm Bob Belderbos — a developer, coach, and builder based in Spain. I spent 11 years at Sun/Oracle building developer tools and software, co-founded Pybites in 2016, and have been coaching developers to ship production-grade software since 2020.

I don't have a CS degree. I came out of a finance degree, got hooked on Unix shell scripting, and taught myself to code by automating everything I could. At Sun Microsystems I became a tool producer for the support org — writing a lot of Perl, then convincing my manager to let me rewrite our automation tooling in Python. That rewrite taught me that you can write clean code in Python from the start, and that the best way to learn a language is by building something real with it. That experience shaped everything about how I coach: less theory, more shipping.

In 2016 I co-founded Pybites, where I built one of the largest Python learning communities — 400+ coding exercises on pybitesplatform.com, a Python developer podcast, 1,600+ content pieces, and a coaching practice that's been running since 2020. I also built rustplatform.com for Rust exercises. Over the years: hundreds of developers coached, 1,000+ pull requests reviewed. In 2026, I branched off to focus fully on developer coaching under my own name — same philosophy, broader scope.

What I believe

The tools change. The fundamentals don't. AI, new frameworks, new languages — the landscape shifts constantly and nobody has the final answers on where it's all going. I certainly don't. But I've watched what stays true across every shift: developers who build real things, understand their systems deeply, and ship consistently — they adapt and thrive no matter what changes around them. An Anthropic study found that junior engineers using AI scored 17% lower on coding assessments — not because AI is bad, but because passive use skips the learning. The developers who did well were the ones actively engaging with it. That's exactly the kind of skill-building my coaching focuses on.

The best developers aren't the best coders. They're software engineers — people who know what's worth building, who ship iteratively, and who own outcomes. Not "Python developers" or "Rust developers" — engineers who pick the right tool for the job. The bottleneck has never been writing code — it's knowing what to build and how systems should work.

Passive learning doesn't work. Before AI, it was tutorial hell. Now it's blindly copying AI output. The fix is the same: build real things under pressure, get honest, detailed feedback from someone who sees your blind spots, and ship before you feel ready.

The coaching philosophy

This isn't motivational coaching. It's a master craftsman pushing an apprentice.

  • Intensive code review — fast-turnaround GitHub PR feedback, detailed and honest
  • Ship before perfect — iterate, don't polish forever
  • Push past comfort — if it's easy, you're not growing
  • Guided discovery — I point you toward solutions, I don't hand them to you
  • AI as a tool, not a crutch — ask conceptual questions, seek explanations, never just delegate

What clients say

  • "I grew more in a few weeks than I would have in 2+ years by myself" — Kishan P.
  • "I'd maxed out every book and online course — Coursera, Udacity, Udemy — and hit a wall I couldn't break through on my own. I expected to build one app. I shipped three." — Joshua E.
  • "I was stuck in the tutorial loop. The program gave me the confidence and real projects I needed" — Heather G.
  • "Last November I knew nothing about coding. Now I am shipping" — Dabrien S.
  • "I went from imposter syndrome to adding Python Developer to my resume" — Lee C.

What I've built

Products

Pybites Platform — Interactive Python exercise platform with 400+ bite-sized exercises. 50,000+ accounts and 270,000+ exercise completions on the original platform, hundreds of active developers on v2. Write code in the browser, get instant feedback, learn idiomatic Python through practice. Django, AWS Lambda code runner.

Rust Platform — The same approach applied to Rust. 61 exercises and growing. Rust exercise validator API built in Rust. Practical, hands-on, no fluff.

Tools and projects

I usually build tools to automate tasks, scratch my own itch, or share something useful with the community:

Pybites Books — A clutter-free, privacy-respecting reading tracker. Search books via Google Books API, track reading status, follow what other developers are reading. Django, HTMX, dark mode.

pybites-carbon — CLI tool to generate beautiful code images using Carbon. Because developers share code visually.

pybites-search — Command-line tool to search across all Pybites content — articles, exercises, podcasts, videos, tips. Originally built in Python, rewritten in Rust as part of my Rust learning journey.

karmabot — Slack bot for community engagement. Track karma points, celebrate wins.

mdweaver — Convert markdown files to beautiful PDFs and EPUBs with syntax highlighting. We use this to generate additional curriculum materials for our cohorts.

Rust

rsbit.es — Rust blog documenting my journey from Python to Rust, built with Zola (a fast Rust static site generator — this site uses it too).

Beyond coaching

I write about developer craft, AI, and what I'm learning on a new blog here. I write about Rust at rsbit.es. You can also follow / connect with me on LinkedIn.

Are you Dutch or Spanish speaking and prefer coaching in your mother tongue? I can coach in these languages as well.

Passionate about coding + coaching, outside work I enjoy spending time with my family, staying fit, and reading a variety of books — from novels to tech / history / philosophy.

Get in touch

Book a free intake call → Let's talk about your goals, challenges, and how coaching can help you grow faster.