Architecture Weekly #96 - 10th October 2022

Welcome to the new week!

I’ve heard a few times that Event Sourcing is hard to test. I’m not sure where this myth comes from; maybe from mixing it with event streaming. Event Sourcing logic is pretty straightforward. We’re getting the list of events recorded for a specific entity (e.g. bank account), building the current state from them and running business logic based on it. As a result, we’re getting either a new event or a list of events. We can think about business logic as a pure function and just verify if, for the defined inputs (state + command) we’re getting the expected result (event or error). In my last article, I explained in detail how to do that:

• Oskar Dudycz - Testing business logic in Event Sourcing, and beyond!

Check new goodies to my small testing library Ogooreck, in which I added helpers to cut the boilerplate of testing business logic (not only event-sourced one).

Tests are great, but nowadays, not all we can verify before production. I wrote once that I tested on production and am not ashamed of it. In the distributed world, we can be certain about one thing: there will always be something that’s not working. We need to embrace that and make our systems resilient to failure. Check more in:

• Uwe Friedrichsen - The right dose of resilience

• Richard Cook - Resilience In Complex Adaptive Systems

That’s also why I like the Event-Driven approach, as it helps with that. It won’t help us to avoid failure, but it will enable us to manage it and be prepared for the worst. Of course, it may also introduce accidental complexity, so it’s always worth questioning what we read. InfoQ released a new eMag about the streaming pipelines:

• The InfoQ eMag: Modern Data Architectures, Pipelines, & Streams

Check also the new Kafka release notes. The Kafka team is pushing for the removal of Zookeeper. On a bigger scale, everything is custom. Kafka provided their implementation of the Raft protocol, called KRaft and aimed to remove the dependency for Zookeeper. It served them well, but they decided they wanted to have more control, fewer moving pieces and make it more fine-tuned to their needs. Read:

• Confluent - What’s New in Apache Kafka 3.3

Speaking of the design. Most of the architects I know come from the backend or operations. We tend to ignore the UI and UX as something that’s maybe nice but not so important. That too often leads to building the iceberg, where we’re trying to hide too much underwater instead of delivering more to users. Check the nice summary about the UI and UX in:

• Miklos Philips - Design Principles: why a design works

From the industry news, read more about the not-great time for NFTs and Metaverse. I’ve heard that “future is now”. It seems that not quite yet.

• Bloomberg - NFT Trading Volumes Collapse 97% From January Peak

• CoinDesk - It's Lonely in the Metaverse: Decentraland’s 38 Daily Active Users in a $1.3B Ecosystem

Have you thought about watching Star Wars on the terminal? I bet you did. See it:

• Abhishek Prakash - Watch Star Wars In Linux Terminal via Telnet

Check, also other links!

Cheers
Oskar

p.s. I invite you to join the paid version of Architecture Weekly. It already contains the exclusive Discord channel for subscribers (and my GitHub sponsors), monthly webinars, etc. It is a vibrant space for knowledge sharing. Don’t wait to be a part of it!

p.s.2. Ukraine is still under brutal Russian invasion. A lot of Ukrainian people are hurt, without shelter and need help. You can help in various ways, for instance, directly helping refugees, spreading awareness, and putting pressure on your local government or companies. You can also support Ukraine by donating, e.g. to Red Cross, the Ukraine humanitarian organisation. You may also consider joining Tech for Ukraine initiative.

Architecture

• Uwe Friedrichsen - The right dose of resilience

• Richard Cook - Resilience In Complex Adaptive Systems

• Christopher Alexander - Patterns in Architecture

• Jimmy Bogard - Domain-Driven Refactoring

Distributed Systems

• The InfoQ eMag: Modern Data Architectures, Pipelines, & Streams

• Confluent - What’s New in Apache Kafka 3.3

DevOps

• RedPanda - Kafka on Kubernetes: What could go wrong?

• Serverless DNS - The RethinkDNS resolver that deploys to Cloudflare Workers, Deno Deploy, and Fly.io

FrontEnd

• Miklos Philips - Design Principles: why a design works

• qwik - The HTML-first framework. Instant apps of any size with ~ 1kb JS

• DaisyUI - The most popular, free and open-source Tailwind CSS component library

Testing

• Tokopedia - GripMock - gRPC Mock Server

Mobile

• The Linux Experiment - OPEN SOURCE your Android Phone: open source Android ROMS and apps

Java

• Brian Goetz - Paving the on-ramp

• Microsoft - How Microsoft applies Java

• Brian Vermeer - Best Practices for Managing Java Dependencies

• ArchUnit - A Java architecture test library, to specify and assert architecture rules in plain Java

.NET

• Oskar Dudycz - Testing business logic in Event Sourcing, and beyond!

• Patrick Smacchia - .NET Build Improvement: Stop Wasting Resources

• Ledjon Behluli - Orlean Spaces - A virtual, fully-asynchronous, Tuple Space implementation backed by Orleans.

• Jonathan George - Bye bye Azure Functions, Hello Azure Container Apps: Migrating from Azure Functions to ASP.NET Core

Python

• Szymon Miks - Optimistic locking with Python

Management

• Continus Delivery - Randy Shoup - Leading Teams For Silicon Valley Tech Giants

• Laurence Tratt - UML: My Part in its Downfall

• Jeff Gothelf - 3 Tools to Help You Keep Track of Your OKRs

Industry

• Lisa Harvey-Smith - More women are studying STEM, but there are still stubborn workplace barriers

• Bloomberg - NFT Trading Volumes Collapse 97% From January Peak

• CoinDesk - It's Lonely in the Metaverse: Decentraland’s 38 Daily Active Users in a $1.3B Ecosystem

Trivia

• Abhishek Prakash - Watch Star Wars In Linux Terminal via Telnet