Kalvad Blog

Validating API json structures with Tavern

Validating API json structures with Tavern

How to validate data and structure of REST API response using open source Tavern

Building angular applications on AWS Amplify

Building angular applications on AWS Amplify

Stability and maintainability of a system is one of the key components that dictates a good practice of building great applications. In my career as a software engineer, I have come to love angular because it is a framework that I have relied on to create scalable web applications. In

The DevOps is dead, long live the DevOps!

The DevOps is dead, long live the DevOps!

Let's be clear, DevOps is just becoming out of control, everything is DevOps, or worst, DevSecOps, DevSecFinOps, DevOpsOps (sic). The original definition of the word is lost, and it is hurting badly a lot of jobs: Sysadmin, DBAs, SREs. Let's put things straight, We Love DevOps, but it's time to

It is Infrastructure as Code, not Infrastructure as YAML!

It is Infrastructure as Code, not Infrastructure as YAML!

Welcome back to our blog, after our summer break! We did one article per week for 51 weeks (yes, we know, almost a year), and we thought that a pause was necessary, in order to have some inspiration and stories to tell! So here we are: choosing a topic, and

Introduction to Quantum Cryptography

Introduction to Quantum Cryptography

Quantum cryptography is a new method of cryptography that it’s based on quantum mechanics laws, pretending that uncertainty has the potency to weaken the ability of an intruder to hack or get into a system by boosting the entropy. Relying on the Heisenberg uncertainty principle, we assume that one

Automation: n8n strikes back

Automation: n8n strikes back

Almost 2 years ago, we introduced a new automation tool in this article [https://blog.kalvad.com/n8n-on-clever-cloud/]: n8n, and we know that some people were using our article to deploy it in production. Here is the small issue: our deployment was made back in the days, and nowadays, a

N8N: RabbitMQ + HTTP + Slack - part 3

N8N: RabbitMQ + HTTP + Slack - part 3

In this blog post we will create a slack app and setup a slack node.

Uptime Kuma, SQLite and Litestream!

Uptime Kuma, SQLite and Litestream!

How can you deploy a SQLite application on almost any cloud provider in a secure and reliable way!

N8N: RabbitMQ + HTTP + Slack - part 2

N8N: RabbitMQ + HTTP + Slack - part 2

In this blog post we will setup a conditional node and an HTTP node.

Archlinux in Production?

Archlinux in Production?

Is archlinux viable in production? Why you should use it too? Is that better than Ubuntu? (YES!!!)

To Cloud or not to Cloud

To Cloud or not to Cloud

Kalvad is very present in the Middle East, especially on certain topics: * Fixers: we are the people who can fix everything * High Performance Systems * Crazy constraints apps Of course, you don't find this kind of setup in a small startup, mostly in big Corporations or Governmental Entities. And as you

N8N: RabbitMQ + HTTP + Slack - part 1

N8N: RabbitMQ + HTTP + Slack - part 1

In this blog post we will setup a rabbitmq trigger in n8n, receive a message and save our workflow.

SQL - Is Your Sort Order Deterministic?
A classic example of S.E.P. (Somebody Else’s Problem)

SQL - Is Your Sort Order Deterministic? A classic example of S.E.P. (Somebody Else’s Problem)

A Forgettable Rule One of the first things you forget about SQL databases is that an un-ordered query can return results in any order, i.e. a non-deterministic sort order. Moreover, the order is not guaranteed each time you execute the query. Here is an example of a query with

Intro to Quantum Computing

Intro to Quantum Computing

With the evolution of technology in the 21st century, a new term has been announced to the public, quantum computing, I'm sure many of us weren’t big fans of physics class, therefore quantum mechanics is probably a nightmare, yet, it is quite interesting that lead to the formation of

Dhakira, the cloud-native Web Server or Why Hosting some static assets is still so complicated?

Dhakira, the cloud-native Web Server or Why Hosting some static assets is still so complicated?

Let's be clear here, I'm French, so I'm complaining a lot! And some people are saying: > Loïc, you should not be so negative! Where are your solutions? So let me tell you a nice story! Static For the Win As you may know, we are huge fans of static site

What do monitoring metrics tell us?

What do monitoring metrics tell us?

Monitoring is a wide topic that provides the real-time status of the health of targeted applications, services, infrastructure ..etc. Real-time streaming of these metrics and visualizing them into graphs are the most crucial parts of the monitoring service. Introduction In this article, we will cover what metrics can tell us

DRY your Phoenix Templates

DRY your Phoenix Templates

Modern web development has brought a lot of changes. Something I really like is breaking your templates in small components. This is something that I had a hard time to reproduce with Phoenix but I think I have now found all the small tricks to write powerful and well-structured components.

Django + Webpack Series: 1. Setup and SCSS

Django + Webpack Series: 1. Setup and SCSS

Why Webpack? Django still proves to be one of the most popular and solid popular back-end frameworks in 2022. However when it comes to front-end, compared by the more popular front-end frameworks such React, Angular, and Vue Django by default lacks lots of the modern features offered in the other

The major root causes behind SLA degradation

The major root causes behind SLA degradation

In the previous article [https://blog.kalvad.com/sla-and-slo-fundamentals/], we described SLO and SLA and how to measure them on a WebServer like Nginx or Apache, and in this article, we will discuss the major root causes that decrease the SLA and how to deal with them. SLA Time-based : Time-based

#4 Discord bot & stackable queries

#4 Discord bot & stackable queries

Fourth article of a series about Phoenix and Elixir. This one will be focused on creating a Discord bot and making Ecto queries easy.

تعرّف على لعبة "مفردات" النسخة العربية من اللعبة Wordle

تعرّف على لعبة "مفردات" النسخة العربية من اللعبة Wordle

في نهاية شهر يناير من هذا العام، بدأ فريق Kalvad في دبي تحدّي بعضهم البعض في لعبة Wordle التي صممها "جوش ووردل" عبر الإنترنت. في وقت لاحق، تنافسنا مع بعضنا أيضاً باللغة الإنجليزية والفرنسية، وشاركنا نتائجنا عبر برنامج Slack. بعد فترة قصيرة، شعر غالبية فريقنا من الناطقين باللغة العربية

Rebranding / White Labelling your Angular App

Rebranding / White Labelling your Angular App

A multi-theme system that operates during build-time

SLA and SLO fundamentals

SLA and SLO fundamentals

SLA aka Service-Level Agreement is an agreement you make with your clients/users, which is a measured metric that can be time-based or aggregate-based. SLA time-based We can calculate the tolerable duration of downtime to reach a given number of nines of availability, using the following formula: For example, a

Haskell series part 10

Haskell series part 10

This is the tenth and last article of a series on the functional language Haskell for beginners

Build your Elixir application as a self-contained binary

Build your Elixir application as a self-contained binary

During the last year, at Kalvad, Elixir has become one of our favourite language to work with. However, there are still some downsides to it and today, we will try to solve one of them: the lack of portability. This post follows another post [https://blog.kalvad.com/write-your-own-cron-with-with-elixir/] demonstrating