iiinova — where your digital self keeps evolving

Bob Belderbos @bbelderbos.bsky.social · 10h

(You also finally learn what `uv init` was setting up behind the scenes in Week 1, when we skipped it with `--no-package`) Let me know how you go ...

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Bob Belderbos @bbelderbos.bsky.social · 10h

→ Add an entry point to pyproject.toml so uv run journal works like an installed tool The behavior doesn't change and the test suite will help you refactoring it: 22 tests pass before + after.

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Bob Belderbos @bbelderbos.bsky.social · 10h

→ Split it into a journal package with a src/ layout (models.py, db.py, cli.py) → Group the storage functions into a `JournalDatabase` class, because every function was being passed the same db_path → Move shared test setup into pytest fixtures in conftest.py

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Bob Belderbos @bbelderbos.bsky.social · 10h

Week 4 of my #Python Foundations course is live. 🎉 This week there are no new features and that's on purpose. 🚀 By Week 3 the journal app is a 117-line main.py that holds the model, the storage and the CLI. It works, but that one file is starting to hurt. 💡 This week you'll refactor it:

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Bob Belderbos @bbelderbos.bsky.social · 16h

Who's been there? Who's there right now? What's the most fragile Excel sheet holding your ops together? #Operations #Automation #Excel #TechDebt

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Bob Belderbos @bbelderbos.bsky.social · 16h

"Let's just make a quick tracker." 6 months later: 12 linked sheets, manual errors, zero version control, and everyone holding their breath during month-end. If a spreadsheet relies on manual copy-pasting to function, it’s not a tool, it’s hidden tech debt.

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Bob Belderbos @bbelderbos.bsky.social · 16h

thanks, are you using it already?

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Bob Belderbos @bbelderbos.bsky.social · 11/10/2026

Where does your LLM code break first: parsing outputs, testing, or knowing when to involve a human? Register: pythonagenticai.com/events/dete...

pythonagenticai.com

Deterministic systems on top of stochastic LLMs — free live event

Wednesday 14 October 2026 · 15:00 CEST on YouTube Live.

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Bob Belderbos @bbelderbos.bsky.social · 11/10/2026

We'll take your questions, then wrap up with a quick 10-minute look at how our cohort program guides you through building your first agent from scratch. 📅 Wednesday, 14 October · 15:00 CEST 📍 YouTube Live · Free · Live event

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Bob Belderbos @bbelderbos.bsky.social · 11/10/2026

None of this is new. It’s just clean interfaces, input validation, and clear boundaries. The same engineering rules that made systems reliable long before LLMs came along. Now they sit alongside a component you can't fully predict.

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Bob Belderbos @bbelderbos.bsky.social · 11/10/2026

→ A Protocol boundary and service layer: swap LLM providers or mock them in tests → Structured outputs: Pydantic models, not fragile string parsing → Human in the loop: the model proposes; your application decides

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Bob Belderbos @bbelderbos.bsky.social · 11/10/2026

It's the engineering around it. And that's exactly what most AI demos leave out. Next Wednesday, Juanjo and I will build a small agent live, showing the engineering decisions step by step: → Tool calling: the agent loop, without a framework

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Bob Belderbos @bbelderbos.bsky.social · 11/10/2026

LLMs are stochastic. Your users expect reliable results. So how do you build a deterministic system around a model that can give different answers to the same input? Most of the answer has nothing to do with the model.

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Bob Belderbos @bbelderbos.bsky.social · 09/10/2026

Do you know a business owner or someone in finance, operations or logistics dealing with this kind of manual work? What process eats up the most time in their week? If someone comes to mind, feel free to tag them or send me a DM.

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Bob Belderbos @bbelderbos.bsky.social · 09/10/2026

This is the work I do now. I map the workflow first. I decide what should stay human. Then I build the smallest system that removes the repetitive part. Workflow first. AI second.

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Bob Belderbos @bbelderbos.bsky.social · 09/10/2026

Supplier invoices arrive as PDFs and get retyped into the ERP. Orders come in by email and get copied into an Excel tracker. The weekly report takes half a day because it pulls from four systems. 🔄

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Bob Belderbos @bbelderbos.bsky.social · 09/10/2026

Most automation projects start with the wrong question: "Where can we use AI?" A better question: where are people moving information by hand?

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Bob Belderbos @bbelderbos.bsky.social · 09/10/2026

Simple, memorable, and much easier to reason about than a page of compiler errors. And there's a learning principle too: you really start understanding a concept when you can explain it in your own words to somebody else. That's something we encourage throughout our #Rust cohort program. 🦀

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Bob Belderbos @bbelderbos.bsky.social · 09/10/2026

Lend your book to multiple readers. They can all read it, but nobody can write in it. - `&mut T` = Mutable borrow: Give someone exclusive access to write. Everyone else has to wait. - `.clone()` = Making a copy: Someone gets their own copy. Their notes stay separate from the original.

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Bob Belderbos @bbelderbos.bsky.social · 09/10/2026

Rust’s ownership rules can feel like a mind bend when you come from a scripting background. Until you find the right mental model. 🧠 Cohort alum Vikas came up with a great analogy: owning a book. 📖 - `&T` = Borrowing:

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Bob Belderbos @bbelderbos.bsky.social · 08/10/2026

In #Python you can get far without that depth. In Rust you can't. It's a hard language to learn alone. We help you build that depth → scriptertorust.com What's the last thing you built to learn that ended up running for real?

scriptertorust.com

Scripter to Rust — A community and coaching for Python developers learning Rust

The Rust Never Sleeps Slack, a newsletter, a Rust exercise platform and small coaching cohorts for Python developers learning Rust.

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Bob Belderbos @bbelderbos.bsky.social · 08/10/2026

If speed were all that mattered, I'd have kept serde. But it's a joy to run my own parser, one I understand in every detail because I built it. And it gives me a real benchmark for the next optimization round. Exercise → crate → production. Code you struggled with and fully own.

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Bob Belderbos @bbelderbos.bsky.social · 08/10/2026

The JSON parser I wrote in our Scripter to #Rust cohort just replaced serde in my CLI. 544 MB of real data: every line parsed. 199 floats differed, and mine had the exact value. But serde is hard to beat on speed: a search now takes 0.4s instead of 0.1s. Fine for a CLI.

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Bob Belderbos @bbelderbos.bsky.social · 07/10/2026

It's the 6-week capstone of our <Scripter to Rust> cohort, and I built it alongside last cohort. I published it so I can use it in another tool I'm building that needs to parse JSON logs, simply: `cargo add bob-json-parser` Check it out -> crates.io/crates/bob-...

crates.io

crates.io: Rust Package Registry

crates.io serves as a central registry for sharing crates, which are packages or libraries written in Rust that you can use to enhance your projects

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Bob Belderbos @bbelderbos.bsky.social · 07/10/2026

Just published a new crate to crates.io: bob-json-parser 🦀 It's a JSON parser written from scratch in #Rust: a hand-written tokenizer and a recursive-descent parser, with no serde. PyO3 bindings let you call it from #Python as a native extension.

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Bob Belderbos @bbelderbos.bsky.social · 05/10/2026

#Git remains one of those technologies developers can use every day without really understanding the model underneath it. Where do you (or people you work with) still struggle with Git? And what helped you get past it?

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Bob Belderbos @bbelderbos.bsky.social · 05/10/2026

Ok ok Claude I am fine with the walruses 🤣 #python

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Bob Belderbos @bbelderbos.bsky.social · 05/10/2026

Forgot to announce last Friday, but week 3 of my Foundations course is live. 🚀 Goal: for beginners to take their #Python dev skills far beyond the mere syntax (talking with people it's everything around it that's difficult). Enjoy and learn a lot -> belderbos.dev/foundations... Final app demo 👇

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Bob Belderbos @bbelderbos.bsky.social · 05/10/2026

Do you grep ~/.claude/projects, or do you use a specific tool for this?

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Bob Belderbos @bbelderbos.bsky.social · 05/10/2026

How do you find & manage #Claude Code sessions? /resume works per project folder. Ctrl+A expands it cross-project, but it's still title-only search. What if you need to search through actual session content (code, terminal errors, past prompts)?

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Bob Belderbos @bbelderbos.bsky.social · 04/10/2026

I'm curious to gauge interest: in an agentic world, do you feel the need for live, human-to-human design and coding sessions has grown? How would you use this? 👇

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Bob Belderbos @bbelderbos.bsky.social · 04/10/2026

Ensemble (mob) programming makes live architectural thinking, trade-offs, and micro-decisions visible in real time. I co-hosted live ensemble sessions back before AI agents, and developers loved verbalizing *why* they chose specific patterns. So I built a lightweight tool for it:

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Bob Belderbos @bbelderbos.bsky.social · 04/10/2026

LLMs can write syntax, but they can’t replace human engineering judgment. As AI agents generate more of our codebases, live design sessions become *more* valuable, not less. Juniors still need to learn how experienced engineers THINK, something async code reviews only partially answers.

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Bob Belderbos @bbelderbos.bsky.social · 04/10/2026

Cohort feedback: > "One detail I absolutely love: you progress by making tests pass. That combination of learning-by-doing, strong engineering practices, and taking something all the way from code to a deployed product is exactly how I think this stuff should be learned." #agenticai #training

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Reposted by Bob Belderbos

Real Python @realpython.com · 03/10/2026

🐍📩 Jev, PyO3, Temp Files, and More at Pycoders Weekly, Issue # 754 pycoders.com/issues/754

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Bob Belderbos @bbelderbos.bsky.social · 04/10/2026

TIL that you can use `workflow_run` in GitHub Actions to trigger CD only after CI completes. 💡 A nice way to make pipelines more modular. 🚀

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Bob Belderbos @bbelderbos.bsky.social · 03/10/2026

Use #AI to its fullest extent, but design strategic checkpoints to keep the system reliable. How are you designing for correctness? #agentic #systemdesign

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Bob Belderbos @bbelderbos.bsky.social · 03/10/2026

How to deal with probabilistic systems (LLMs)? Build deterministic systems around them. My expense invoice scanner is a good example. The LLM reads the invoice and shows me what it finds. I can accept, edit, or discard the result before anything gets added to my records.

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Bob Belderbos @bbelderbos.bsky.social · 02/10/2026

Agents write code fast. Knowing whether it's right is the slow part. In our cohort you write the code yourself first, learning the patterns behind reliable agents: typed data, Protocols, a service layer, and "the model proposes, you decide". → pythonagenticai.com

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Bob Belderbos @bbelderbos.bsky.social · 02/10/2026

Join here: bookclub.belderbos.dev Like this idea? Like + share the video: www.youtube.com/watch?v=G1wS...

bookclub.belderbos.dev

Book Club

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Bob Belderbos @bbelderbos.bsky.social · 02/10/2026

Start: next Monday Book: The Pragmatic Programmer Compound effect: if success, continue -> 52 weeks / ~10 chapters a book = 5 amazing books read + discussed in depth in a year! #programming #books #bookclub #developer

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Bob Belderbos @bbelderbos.bsky.social · 02/10/2026

In an age where we're constantly urged to move faster, sometimes we have to slow down 🏃 💡 So I'm starting a book club: - Read and discuss a classic programming book - 3 weekly threads to discuss learnings + experience - If enough people, get on a call to dive deeper

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Bob Belderbos @bbelderbos.bsky.social · 01/10/2026

And judging by the feedback I get, this is also what people seem to value most in my videos: watching the thinking behind the code so the 'how' + 'why', not just the 'what'.

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Bob Belderbos @bbelderbos.bsky.social · 01/10/2026

We'll see how much hand-coding remains in the industry, but I do think regularly writing code yourself is a great way to keep your technical skills and intuition sharp.

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