Recursion refers to the property of a function to be defined in term of itself. The Fibonacci sequence is a great example of a recursive problem where a Fibonacci number is calculated from a combination of precedent Fibonacci numbers. Recursion can be implemented in many forms, it is even possible to implement recursion without explicit self calling. Today we will look at different implementations of Fibonacci and discover their properties.

In programming, we often hear about Closures. Closures are present in any languages possessing functions as first class citizen. This includes functional languages and also widespread languages such as C#, Python and JavaScript. Today we will look at the origin of closures and understand what they are.

Last week a colleague of mine introduced me to the concept of continuation in Racket (the best of Scheme and Lisp - at least that is what racket-lang.org states). I knew about the existence of Lisp but I never really paid attention to what it provided as language features. So I took the bite and started to read the post shared to me on continuations, written by Matt Might and oh boy… was I confused. Everything about the code confused me, the notation, the syntax, and of course the flow of the program itself. What I understood was that this piece was implementing Exceptions by using continuations which was enough to make me want to understand it.

Property-based testing is a testing method where a property of our system is tested against multiple datasets. Today we will see how we can create property tests using Hypothesis in Python.

Flask is a microframework for python providing building blocks to compose websites and web API quickly. It has a vast ecosystem driven by open source libraries maintained and used by many developers. Today we will see how we can setup a simple todo web API using Flask and how we can setup OpenAPI 3.0 (OAS3 - previously known as Swagger).

Prometheus is an open source monitering platform. It provides multiple functionalities to store, manipulate and monitor metrics from our applications. Today we will see how we can push metrics from an ASP NET Core application, and how to make sense of it.

Blue-green deployment is a method used to reduce risk and downtime during deployment. Today we will see how we can implement a fully custom Blue-green deployment for a single server setup using Nginx and using Gitlab CI for continuous deployment.

Jekyll is a blog aware static site generator. Blog aware means that it ships with functionalities to build blogs and blog posts. The two major benefits from Jekyll are the markdown translation to HTML and its blog creation orientation. I recently migrated out of blogger and moved to building my own website using Jekyll and today I will share the steps I took.

Load testing helps catch problems which only appear in high load. A common use case of load testing is to load our API with an amount of request of two or three times higher than the usual load. This will provide confidence in our API ability to handle larger traffic. Today we will look into Vegeta, an open source HTTP load testing tool quick and easy to setup. In this post, I’ll demonstrate how quickly and easily we can load test our API endpoints.

I have been using state management frameworks for the past few years, mainly with Angular and NGRX. Today we will see how we can get started with Create-React-App using Mobx as a state management system.

Securing communication between client and server is a mandatory step when building web application. Thanks to Let’s Encrypt, it is now free to setup SSL certificate and with Certbot, the ACME protocol implementation available on Ubuntu, it is a five minutes job to get it to work with Nginx.

Last week I updated all my packages and realised that everything was broken! The reason why was that rxjs decided to move out of extensions on observable in favor of pipable functions in version 6.x. A major breaking change where majority if not all codebase built using rxjs needs to be changed. Today we will explore the reasoning behind this change.

Last year I talked about Entity Framework Core, an easy and feature rich ORM which makes working with database in a .NET environment typesafe. But even though it makes things easy, there are ambiguous cases which can take us off guard. Today we will see four of this cases and how to deal with them.

In Angular, it is common practice to execute commands prior routing a page using guards and resolvers. Guards prevent the routing from occuring until the condition turns to true and resolvers prevent the routing from occuring until the data is returned. Those actions can take time to complete and during the time being, the component will not load leaving the user with an impression of unresponsiveness. Today we will see how we can implement a navigation loading bar for Angular using PrimeNG progress bar component.

Last week we saw how we could Setup CloudWatch to push logs from our application to CloudWatch. Apart from the application logs, another type of logs that is worth looking into are the access logs from Nginx. Nginx being the entrypoint of the application, every traffic in and out goes through it and today we will see how we can leverage its access logs to monitor the response time of our application from CloudWatch.