Codex, ever the confident bullshitter

As an exercise, I'm committing to fully modelling the flow before touching any code. Also discussing and tweaking the model with both Codex and Claude, to compare.

Started building a seat reservation demo app, that should be a good playground to test stream-less Event Sourcing (ie "Dynamic Consistency Boundaries")

Call me idealistic but I think there should be legal consequences for bombing schools full of little children.

I'm trying Deciduous. Building "narratives" you can revisit out of Gut history is such a cool idea, whether you feed it to an LLM or my own puny human brain. deciduous.dev

I'll be doing an Event Sourcing workshop at Haggis Ruby in Glasgow, this April haggisruby.co.uk The rest of the lineup is looking amazing. This should be good!

The eventlanes.app MCP works great for making sense of existing codebases. You can ask Claude to use it to model the high-level flow of existing codebases (in any stack and/or paradigm), and it's helpful!

Playing with duplicating nodes to turn cyclic diagrams into DAGs, and a hierarchical layout to better present causality in big models.

Re. LLMs: they’re here. They’re a thing that’s happening and they’re massively disruptive to our jobs. Best thing for me as a developer right now is to try and understand what the implications are. Worst thing is to cover my ears and go “lalala I don’t like LLMs!”.

Not a terribly productive day, but I had two very illuminating technical conversations (illuminating in different ways) and I’ll count that as a win

CRUD only seems simpler because you're leaving the workflows to be assembled by each user in their heads.

New in eventlanes.app: Given When Then scenarios for defining test cases.

I added a naive "information completeness check" to eventlanes.app, borrowed from Event Modeling. For nodes that define schemas, it warns you when a node has fields not provided by any nodes it feeds from. It can help account for all data needed across the system, and flag up any gaps.

Whatever you think of LLMs, Claude Code's plans are a thing of beauty. I just want to read and discuss the plans, not even write the actual code.

Just a normal trip to the local library with 7yo.

USA: free markets rule, countries should be free to trade without barriers. Countries: awesome, I just got this really good deal with China USA: no not like that

Looks like it's entirely possible for my Sourced library to support stream-less Event Sourcing, while preserving the Actor-like semantics it currently has. I'll have to blog about why this is cool (IMHO).

Event Sourcing decouples the decisions made by your software from the decision-making code. This means you get to change the decision-making as the domain evolves while keeping all the past decisions around if you need them, or re-interpret them in service of new requirements.

I'm convincing myself that Dynamic Consistency Boundaries are the future of Event Sourcing, especially in the age of LLMs. Now to deal with all the sunk cost put into stream-based ES.

Thank you for the great feedback @ted.dev . Node aliases available now. Great shout!

At the Natural History Museum yesterday, a dad points to the huge whale skeleton above and says to boy: “what an amazing dinosaur!”. Later, a mum points to giant sloth’s skeleton and says to daughter: “oh look, a polar bear!”. As if they were goading me into a public nerd-meltdown 😭

“You’re my father. You need to start taking responsibility for my actions”

Long overdue.

Playing with a new "Subtrees" layout to see conditional branching flows more clearly

This is Sourced parsing the Ruby code in Eventlanes, and using Eventlanes to diagram it. This is the (real) flow to make a copy of a model.

My little Eventlanes app has a REST API and an MCP server, both generated off of the same Ruby specification. Define the endpoints once, and they become available as REST and MCP operations. eventlanes.app/p/about

Two separate threads link together again: turn real event-sourced Ruby code into diagrams. This will be available by default in any Sourced app.

- 7yo: What are you working on dad? - Me: It's hard to explain... - 7yo: I want to know! - Me: Ok... I'm building software used to build other software in a particular way. The idea is that you have events that... - 7yo: loud mock-snoring.

Great song with shoegazing and Stereolab vibes www.youtube.com/watch?v=VzRy...

Today's Sourced optimisation: make the workers use a single notifications channel instead of dumb polling. Before and after with a couple idle workers. And workers are now near-real time.

Spent same time implementing batch processing for Sourced, my Ruby event-sourcing toolkit. Background reactors now catch up with pending messages in batches. This benefits projector rebuilds in particular. Admittedly the bar was low, but this is the before (batch size = 1):

Quick diagramming in Slack

eventlanes.app can now produce image URLs of diagrams. Paste anywhere!

A friend just used my hobby project eventlanes.app via MCP to have Claude turn his diagrams into a little event model, to visualise the entire feature, and then implement it in Elixir. It just worked!

eventlanes.app now supports multiple users collaborating on a domain model.

Collaborate on diagrams.

LLM happily adding tests in Given, When, Then format. Event Sourcing and LLMs are such good friends.

Ok. My diagramming app's logged-out mode is somewhat useful now. You can edit the playground model, and share public read-only links. Free to use! Any feedback welcome. eventlanes.app

live modelling with Claude

I got as far as building a local-first, locally event-sourced app with server sync and basic conflict resolution UI. It's cool tech and lots learned, but I think it's time to simplify to what's really valuable, so this will all mostly go away.

LLMs are now just extraordinary. I asked Claude to use my app to diagram an implementation plan (not what the diagrams were designed for). It worked out how to map implementation concepts onto diagram nodes, and it's actually helpful.

LLMs make some design choices in framework design irrelevant (or event counter-productive), and others tremendously beneficial.

Using eventlanes.app to build eventlanes.app

Same problem, from different angles: how to turn REST APIs into MCP servers, in Ruby: A). An API development toolkit that auto-generates OpenAPI specs, that can now turn itself into an MCP server. Build a REST API and an MCP server in one go. Chat with your API! github.com/ismasan/step... B)...

I wasn't even into the whole LLMs business, and now I'm about to write an MCP server. What has the world come to!

Today in Ruby: succinctly turning Event Sourcing command handlers into self-documenting REST endpoints.

Me: "Claude, how can I add support for X to this library I wrote last year?" Claude: "This library already supports X. This is how you use it:"

You already know Markus Schirp from his mutation testing workshop that he will run at #wrocloverb. And now he’s stepping on stage as a speaker too 🎤 Markus will give a talk titled “My core skill never was the typing” - expect sharp insights and plenty of food for thought.

Brexit always was a tribal battle cry in the culture wars. It doesn’t mean anything practical nor practicable.

Love me some "try-able" documentation!