João Esperancinha articles - 32 total
Implementing a Geo Location module using the Haversine formula
On the 2020/06/06 I published my first Python module. It's a Geo Location calculator which uses the Haversine formula to calculate distances.
Making reactive applications with a Kitten Care Example
Reactive programming is a very important art and a very interesting subject. It uses the Publish/Subscribe pattern or in other words the Observer pattern. With this fun example we'll demonstrate how it works in practice with Kittens!
How to make the best of a slow machine running on limited resources with a Windows environment as a Java Engineer
When we get into the job market, not always we get the best machines to work with and to make the things we love. Having a Windows machine isn't necessarily bad news, but the machines that usually come with it, either have limitations or you end up needing more tools than the ones that Windows seems to offer. Nonetheless, many things are actually very much possible with a Windows machine. They usually just have a different shape.
Redis Cache - A String story
Discussing why it is important to use the right String types when putting data in Redis
Pub-sub Redis in Micronaut
How to create pub-sub redis architecture using Micronaut
How to Manage Your APIs Across Multi-Cloud Environments
Kong Konnect is only the beginning of the journey. We will see how to manage your APIs across multi-cloud environments
ISBN Stacks — A look at a possible Spring Application implementation without annotations
Want to learn how to program a spring application without annotations, and what are the benefits of it? Let me start by saying CDI is different and much less magical. Learn why, in this article.
City Library — An advanced guide to Circuit Breakers in Kotlin
If you already know what circuit-breakers are, then this article could enrich your experience working with them, so come along and learn the greatness of Circuit Breakers!
Monitoring Secure Coroutines and WebFlux Reactive applications with Prometheus, Grafana, and InfluxDB — A webcams example
Monitoring applications can easier said than done. What if I told you that it can be easier and it can be done? Let's try Grafana and Prometheus!
Learning JWT security using KumuluzEE — The finances of a league of the environment
Ever wondered how to create a JWT token and what does that actually mean? How about using it in something relatively unknown? Let's see that with KumuluzEE!
Kotlin Coroutines vs Java Virtual Threads — A good story, but just that…
So what is the big difference between Kotlin Coroutines and Java Virtual Threads? Aren they the same under a different management? How do they work with each other and can they work together with each other
Kotlin Native and GraalVM - The Story So Far
Did you know that we can compile Java and Kotlin code, even Python to binary native code? We can skip JIT with it and improve start-up times. How can we do that? This is what this article is about!
Protecting Applications with Kong security plugins and using StatsD to monitor system states — A healthy camera story
How can we monitor our application with StatsD and could be the setup to allow that to happen? Find out in this article and how to use that in a Kong plugin
Configurable Kong API Gateway with Micronaut Services in Kotlin — A very odd Yucca tribute concert
What is an API Gateway and how can we use it? Kong offers that and in open-source form as well. Find out how the OSS version works!
Learning AWS with Localstack and Reactive Kotlin — A stamps and coins implementation
Working with Localstack can help us understand AWS a bit more because we can run an environment that acts in a similar way to AWS Cloud Services
Coroutines, Distributed Cache, Resilience, and Replication in Kotlin — Making a VMA’s application
We talk a lot about reactive, but reactive is also meant to make our applications resilient as possible, but what does that mean?
From Paris to Berlin — Creating Circuit-Breakers in Kotlin
What are circuit-breakers? The stop a circuit when something wrong is happening right? But how can we control that?
NewsCast — Using Sagas with Choreography and Orchestration Patterns — Kotlin example
The Saga design pattern has amazing benefits in terms of resilience. We can do that with the Eventuate libraries and Kotlin. Here is how!
The streaming bridges — A Kafka, RabbitMQ, MQTT and CoAP example
How can we use data stream and what does that mean? Does Kotlin really offers an alternative?
Chrome OS Guide to go from Zero to DevOps Hero in a nutshell
Do you have a Chrome OS? It may work great for you dev endeavors
Deploying Mancala with Minikube — A beginners guide
What is minikube and how is it related to Kubernetes, which we frequently name k8s?
Comparing WebFlux and Spring MVC with JMeter and Kotlin
Can WebFlux be better than the tradition MVC? Why and why not? This is your test to clear that up!
Reactive Programming applied to Legacy Services — A WebFlux example
1. Introduction The concept of reactive programming can be traced way back to the mid-60s....
CQRS — Command Query Responsibility Segregation — A Java, Spring, SpringBoot, and Axon Example
Introduction The first time this term appeared in Software Engineering lexicons was all...
Hexagonal Architecture — A Favorite Lyrics Spring Boot — Java Example
Introduction This architecture principle was created by Alistair Cockburn in 2005. This is...
Decoding Kotlin - Your guide to solving the mysterious in Kotlin
On the 24th of April 2024, I gave a presentation about Decoding Kotlin at the JetBrains Headquarters...
Kuma Meshes Head-On - A beginners guide
To quickly start learning Kuma, on of the most important things we need is cluster. Then we also need...
They said to use the Default Dispatchers but I found out it was Unconfined
If I would have to point out one of the most confusing Dispatchers in the world of Kotlin coroutines,...
What is the Purpose of the Main Dispatcher?
If you have this question, perhaps you are a long time server-side developer and are wondering what...
When thinking about Java fields we use-site target in Kotlin
One of the greatest strong points of Kotlin can also be its weakness. When we talk about data classes...