LDNUG September 2022 with Lucy Mair and Ian Cooper

London .NET is back! After a long hiatus during COVID, we're delighted to be organising in-person events again, and in September we're going to be at Microsoft Reactor in Shoreditch, with Ian Cooper talking about adopting polyglot flow, and Lucy Mair talking about property-based testing.

Ian Cooper: Adopting Polyglot Flow

There are many brokers that we could consider using when building an Event Driven Architecture. Do we go with Kafka, RMQ, Pulsar, NATS to name but a few? Vendors make bold claims, promising that their broker alone is adequate to form the digital nervous system for your architecture. What should you do?

In this session we argue that one type of broker may not meet all our needs. Akin to polyglot programming - picking the best language for the job - or polyglot persistence - picking the best database for the job - when using Polyglot Flow we pick the best broker for the job.

We will look at the different protocols for messaging: series and discrete and understand their different characteristics with examples in RMQ and Kafka. We will also look at the functionality that brokers may have such as dynamic routing, requeue and dead letter queues, delay queues, and consumer groups and the scenarios that we enable with them. We will look at the ecosystem that surrounds that broker, such as support for aggregation and filtering. Finally, we will consider the environment - how does running on Kubernetes impact your choice of broker?

We will then ask the question, how do you evaluate your architecture's needs to determine which characteristics you need and thus what is the smallest set of brokers you can pick to meet them, without having to work around the limitations of any one broker. By the end of the session you should be able to understand if you can survive with a monoculture, or if you need to embrace Polyglot Flow.

Ian Cooper is a Polyglot Coding Architect based in London, the founder of #LDNUG, a speaker, tabletop gamer, and geek. Tattooed, pierced, and bearded. The 'guv' on @BrighterCommand, he's on Twitter @icooper

Lucy Mair: Property-Based Testing:

aka "the power of a hundred unit tests without writing a hundred unit tests". How do you unit test a function? Typically, one might identify different sets of inputs (for example, for an integer you may have have sets for positive, negative, and zero) and write a single unit test using a single example from each set. Can you be sure your code is correct for the whole set? Maybe it only works for that particular example?
Property-based testing is an approach to testing that involves specifying statements that should always be true (for example, reversing a list twice will give the original result) rather than relying on specific examples. In this talk, I will be giving an introduction to property-based testing, why you would want to use it, and how you might apply it in the real world.

"Hi, my name is Lucy. I'm a senior front-end software engineer at Codat, where I work primarily in TypeScript and React. My main passions on the programming front are functional programming and testing. Outside of work, I like to make things. My hobbies include knitting hats and scarves, arbitrarily putting paint on a canvases, and decorating my lovely flat. I am happiest when I have a little project to get lost in. I have recently sewn my first dress."