How should two microservices communicate? Let’s analyze two different communication patterns: Polling: Service B periodically query Service A for the current state of the users and updates its local storage. Event driven: Service A publishes in a queue every time user information is updated. Service B consumes the updates to stay up to date. Using TLA+ we are going to model the two different patterns to see how well they fit our requirements.

In this guide, I want to demonstrate how to use TLA+ to specify a simple serverless system. AWS defines serverless as: A serverless architecture is a way to build and run applications and services without having to manage infrastructure. You design your system as a collection of small runtime entities, often connected to queues to exchange messages. AWS offers services like Lambda and SQS to easily provision such systems.

Last week, I’ve re-read “Test Driven Development: By Example” by Kent Beck. I was amazed by the simplicity of his process, consisting of small pragmatic steps. So, I decided to put the process to the test in an unfamiliar domain. The kata In this kata, I am going to develop a serverless service in AWS using a Lambda and the API Gateway. I chose this task because, on the one hand, it will contain a fair amount of infrastructure code, which is considered hard to test.

This is a blog post about the trade-offs I’ve observed during agile software delivery with test driven development (TDD). Agile and TDD are amazing, and I use them daily. My hope is that by raising awareness about the trade-offs of our decisions, while applying Agile and TDD, will help us make better decisions. Agile software development Agile software development is a balance of two priorities. On the one hand, we need to develop an application that satisfies the current requirements completely, correctly and economically.