CI/CD stands for Continuous Integration, Delivery and Deployment. But if you still wonder what advantages CI/CD brings and why it is difficult to imagine modern software development without it, then this article is for you!

We’ll use an example of an imaginary web application and see how adding CI/CD pipeline helps at different stages of product evolution.

With that, let’s begin!

Let me introduce you to Kate. She is a product developer👩🏻‍💻 and she came up with an idea — an app to help people find the nearest ice cream shop🍦. After a week of work she created a simple…


Did you ever run into a scenario where you wanted to transform objects retrieved from Amazon S3 “on the fly”? For example, to convert a file to a different format, or exclude sensitive data, or resize, compress and transform an image?

Then you’ll be happy to hear that recently added Amazon S3 Object Lambda offers exactly that, a capability to modify the output of a standard S3 GET request.

I couldn’t stop myself from trying out this new feature and, as a result, wrote this step by step guide to use S3 Object Lambda to generate thumbnail images for an…


While working with the network infrastructure you will undoubtedly run into defining subnets and groups of IP addresses. If you’re new to this, you probably find it challenging to understand the logic behind the notation that is most commonly used to describe a range of IP addresses.

This short article will help you understand what CIDR is and how to read it .

To make it easier to define an IP address range we use CIDR. It stands for Classless Inter-Domain Routing and it is an annotation system. When you saw something like 10.0.0.0/16 — it was a CIDR block.


My Sundays usually start with a cup of coffee and a German class 📚

I have an amazing teacher, who persistently corrects my mistakes and puts words I have difficulties with in a document we share.

As not such a good student, I rarely check that document later and almost never practice new phrases between classes. Which means that at the next lesson I continue making same mistakes.

Today after my class I came up with a better practice mechanism, which I can combine with my chores or evening walks.

The idea is simple — I need someone to tell…


Recently I’ve taken two AWS certification exams. One for AWS Certified Solutions Architect Associate and another one for AWS Certified Developer Associate.

I’ve taken a number of exams in the past, some for foreign languages, other for technologies. I find the exam structure to be useful for setting learning goals and solidifying knowledge. With AWS specifically it gave me stronger motivation to look and experiment with services which I don’t use on a daily basis.

Because most of the test centers were still closed, I decided to go for an online option and do something I have never done before…


This is the third part of the series where we talk about what happens when you use your browser to open a URL.

You might also want to check Part1: DNS or where to find the server and Part2: TCP or how not to lose the data on the road.

Now that we established a reliable connection with the server, it is time for us to talk about privacy and security of the data we are about to exchange. We don’t want anyone on the Internet to eavesdrop on our private data, regardless if it is the latest pictures of…


This is the second part of the series where we talk about what happens when you use your browser to open a URL.

You might also want to check Part1: DNS or where to find the server and Part 3: TLS or how to protect your secrets.

Now that we have a destination address for our web application, you might think that it is a time to request a page we’re interested in. But no, not yet!

Before we can send a request for the page, we still need to do a couple of important things. …


There are plenty of things we take in life for granted. Hot showers, frozen pizza, the Internet.

In this series of articles I would like to give appreciation to something we do almost unconsciously hundreds of times per day, rarely admiring the complexity which happens behind the scenes. Or, should I say, behind our screens?

I’m talking about what happens when you use your browser to search or open a URL.

Let’s go on a journey into the deep woods. We’ll look at the tricks up our browser’s sleeve, we’ll check numerous spots while searching for the IP address. …

Olena Kutsenko

Software engineer, who is passionate about agility and sustainable software development achieved through simplicity, technical excellence and good design.

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