Senior engineer · Developer coach · Pybites co‑founder
Bob Belderbos · 150+ developers coached · 13 years at Sun Microsystems and Oracle · Pybites co‑founder
“Last November I knew nothing about coding, now I am shipping. I still can't believe it.”
“Every morning Bob gave feedback on my code. In 3–4 months I learned enough to build three MVP-ready apps.”
“I've gone from an accountant with very limited programming experience to building three full-stack Python applications!”
“I grew more in a few weeks than I would have in 2+ years by myself.”
“Six years later, I can see that doing the coaching was a great decision.”
Step one
Pick the line that fits. It marks your starting point on the path below.
The path
Each course is one real project. Start where you are, and move to 1:1 whenever your own project is what matters most.
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Your first Python app
Build a tested Python CLI and ship it to GitHub: uv, git, pytest, and your first pull request, with the option to publish it to PyPI. Next: Full-Stack Python.
Start free →
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Architecture fundamentals
Build a full-stack snippet manager: one clean core behind a CLI, a REST API and a web UI, the repository pattern, and a deploy. Next: ship a SaaS.
See the course →
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Ship a SaaS app
Ship a real multi-tenant SaaS with Django and HTMX, deployed on Fly.io. Build a content calendar with a sign-off workflow, modeled as a tested state machine. Next: specialize in AI agents or Rust.
See the course →
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Specialize · AI agents
Build and deploy a production AI agent, from architecture to tests. Ship an expense agent with function calling, structured outputs and three interfaces: Telegram, web and a REST API.
See the course →Specialize · Systems programming
Learn the systems language that makes you a better Python developer. Build a JSON parser from scratch, callable from Python using PyO3. Then benchmark it against established parsers like Python's built-in json.
See the cohort →You are here
Join from any step · Done with you
Not lessons, not a curriculum. I join your project: we scope it, decide what ships first and build it together, so it holds up in production and you understand every line. Scoped to your project, at a fixed price agreed up front.
Why a course, now that AI can answer anything?
AI is an accelerator, not a compass. These courses teach you the judgment and engineering skills to steer it, so you ship faster and understand what you ship.
Self-paced
Tests define done, not a chat that never ends. When they pass, you've built what the week set out to build.
$ uv run pytest -q FFF......... 3 failed, 9 passed # build, understand, run again $ uv run pytest -q ............ 12 passed
1:1
We go through it together: architecture, tests and the code the AI wrote. Then we fix what matters first.
- rows = db.execute(SQL).fetchall() + rows = repo.open_invoices(org)
Results
Knowing what to build, what to leave out and when the AI is wrong. That's what makes a developer senior, and it's what we work on.
Ryan thought big from day one: his own payroll business. Three months after writing Hello World, a company ran its entire payroll on his app. “Seeing someone have that trust in something I built is surreal.” See thepayroll.app.
Luca could already get Claude to build features. The next step was learning to evaluate the architecture, challenge design decisions, and ship a SaaS with payments, settings and tests he could defend.
Piotr signed up wanting to write production-quality code and find more fulfilment in his work. Six years later he's a Senior AI Engineer and team coordinator: “both were in my plan, though I wasn’t sure I could do it.”
From 1:1 coaching and the Rust platform
“Bob coached me through the parts I couldn’t validate on my own: Django settings architecture, payment security, error handling patterns, query optimization. […] More than anything, his coaching gave me the confidence to actually ship.”
“I expected to build one app. I shipped three.”
“We skipped basic coding skills and tutorials and worked on project management and resolving larger design decisions.”
“I learned to think more systematically about code organization: separating concerns between models and business logic, choosing the right validation approach (Django vs Pydantic), and writing maintainable software that scales.”
“More importantly I became a critical thinker, developing a 360° view of my coding skills and how I could become more valuable to my employer and the market.”
“Now, heading into my next promotion cycle, I feel significantly more prepared and confident in my engineering skills.”
“I learned how to think like a developer.”
“The biggest benefit was understanding exactly where I was and having a clear vision of how to reach a professional level.”
“Pair programming with my coach showed me the problem-solving workflows of experienced developers, and I came away with a clear approach to my own development workflow.”
“Two of my three apps are now in production and got good recognition among my peers.”
“I didn't think I'd have time to learn Rust with its steep learning curve but I love it!”
“Also really like that the exercises don't give you straight answers in any way but hints what to study. This forces you go deep in the theory and really understand what you are doing.”
Tell me what you're building and where it's stuck. If a self-paced course gets you there for less, I'll tell you.
Training a team? See team programs. Automating a business process? See consulting.
Bob
Why should a view know about SQL? With a repository here, this test stops needing a database. Your call: which one do you want to defend in six months?