meet.js Wrocław

Description
In this talk, I will demonstrate how so-called good practices combined with a shallow understanding of the domain can create a dangerous illusion of control.
Using a real-world example from the Connected Health domain—specifically, liver cancer risk alerting—I will show how a noun-driven design approach leads to excessive coupling and brittle systems.
The talk will explore common architectural pitfalls such as context violations, database coupling, domain leakage, and mixing read and write models. I will also challenge a popular industry belief by explaining why Clean/Hexagonal Architecture is not an architecture.
Attendees will leave with a clearer understanding of how design decisions shape system behavior—and how easily “best practices” can fail when the domain is misunderstood.
The talk is based on this article.
I’ll be presenting the Miro board and Visual Studio Code. Tech stack is NodeJS/TypeScript/PostgreSQL.

Bio
A software engineer with 15 years of experience, currently working as a hands-on Solutions Architect and consultant, helping development teams deliver better products. He focuses on collaboratively designing solutions with clients—evaluating ideas, assessing risks, and translating them into technical requirements aligned with business goals.

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​Szymon Biduła - The same team yet different: how JS stack is powerfully adaptive in AI world

Abstract
There is a saying that you should be careful what you wish for. We are a unicorn FinTech startup, 4+ years in production, processing $200M+ USD. As we grew 50% year-over-year, NodeJS was our engine - a stack notorious for its philosophy of freedom and anarchy.
But we started to pay the bill. Weekly post-mortems, 16% of workload for bug fixing, and another 20% for research, if the feature is even possible. The dream was becoming a maintenance nightmare.
Then, we started a side project: same domain, same people, but accelerated with AI. We found we could deliver fast and keep NPS positive. By applying principles from the side gig, the main project recovered.
The lesson? A solid JS core can be cloned and boosted by AI in ways other stacks (like Ruby) struggled to match. This is a testimony to JavaScript’s power to adapt to radically different environments.

About me
So old that remembering when going to the cloud and being agile was the hot thing. In my youth I have been scanning brains using fMRI, then I switched to creating applications for portfolio managers dealing with multi-billion portfolios. Currently, architecting Fintech solutions for US-based clients. Privately, a fan of Star Trek and vinyl collector.

My goal is to show you how we deal with the latter at aleno. It's not magic, just an awful lot of ~~monkey-patched code~~ instrumentations. And the result? A clear trace view, just like this one. Oh, and you can create charts from it, too!

Tags
Grafana, OpenTelemetry, Prometheus, Tracing.

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Szymon Bartczak - How to Pass the Context?

Abstract
It’s just another ordinary day for your Node server. A request shows up, gets processed, receives a response, and disappears without a word. No thank you. At best, it leaves behind a quiet ACK.
But every single request carries something with it - a Context backpack. And somehow, your server is expected to carry that backpack all the way through the journey.

One day, you got curious. You set up cameras to watch these requests more closely, to see what really happens along the way. And that’s when things got strange.

The camera crew follows everything... except the backpack. They see the request, they trace its path - but they never seem to carry the Context with them. And yet, somehow, they always know what’s inside.

So how are they doing it?
Maybe the backpack doesn’t need to be carried at all. Maybe it can be stored somewhere safe - like a locker - and picked up only when something inside is actually needed.

In this talk, I’ll walk you through how we can do exactly that - no extra packages, just a few lines of code. We’ll build a simple way to store and access context, and explore what else we can sneak into those lockers.

And in the end, we’ll take a peek behind the scenes of our mysterious camera crew to see how OpenTelemetry pulls it off.

Tags
async-hooks, AsyncLocalStorage, OpenTelemetry, Context Propagation