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DevOps/Software Engineer| Consulting | Mentoring | hiretheauthor.com/steliosmoschos | smos.gr

“Explore, Learn, Teach, Mentor, Expand” — My motto.

“Who are you”?

Hello! I am Stelios. I am from Greece and I have been living in the UK for about 8 years. Before I settle here, I’ve lived in Madrid, Spain. I speak 4 languages (Greek, English, Spanish, German) and I am making my first steps with Russian — very soon.

“What do you do”?

Workwise, I am a consulting software engineer interested in software development & automation. Currently I am working on a large Telco softwarisation project. Lately I have been focusing on skilling up and sharing my findings. This is why I have started writing on Medium too. …


A quick glimpse at the two most popular open-source IaC tools

Infrastructure as Code (IaC)

For many years, network and hardware engineers struggled to install and configure servers and other networking devices. In the past decade, following the big surge of the cloud, these activities were deprecated due to the move to the cloud.

Photo by Ian Battaglia on Unsplash

Nowadays, it’s also become a lot simpler for the software engineers to design, build and power up the required infrastructure. All they have to do is requesting a virtualised component and pay for the relevant Cloud charges. Infrastructure as Code was born out of this situation. AWS with its IaC tool, called Cloudformation, wanted to…


AWS announced a new challenge; to set a goal for earning AWS Certified Solutions Architect — Associate. The only requirements is to fill out the form here and plan the…


FinOps is an interesting and very important topic for many organisations. Following the unexpected traction received by my previous two blogposts about “Killing AWS resources to save money” (here and…


I managed to cut my billing down to what I really expected and I only had to use obvious steps and certain tools. I was not aware for most of them…

I had a bad experience with AWS, but it was not their fault!

I followed various online tutorials on how to continuously deploy my infrastructure using Terraform and Gitlab CI.

However, I closed my computer and left everything running for 3 days!

When I remembered it, I was already been charged for running 8 EC2 instances within an EKS cluster. I terminated them.

The bill kept climbing. I turned off the autoscaling groups. The bill kept climbing. I figured out another 16 EC2 instances were running in Oregon and Virginia (I am based in London)!


More advice on not getting charged for unneeded resources

I have recently written a blog post about a sad situation where I received an unexpected bill from AWS. That was because I made the mistake to follow three different tutorials on EKS deployment with Terraform which resulted in the creation of EC2 instances in 3(!) different regions. That was mainly my fault as I did not pay attention to the autoscaling groups setup and everything kept starting up again and again, even after I was terminating the instances and the cluster itself.

I decided to write a follow-up because of the amazing feedback I received from many people on…


My advice on not getting charged for unneeded resources

When I have free time, I like spending some time on AWS to understand and learn various concepts. It does not mean I like spending $$$ on AWS and you have guessed right — this is what I am going to talk about!

Photo by Sebastian Herrmann on Unsplash

I was looking at deploying continuously an Elastic Kubernetes Service (EKS) using Terraform and Gitlab CI. By the way, I am planning to write about this very soon. Back to our topic now, the final bill of spending some nice time and money on AWS in April 2021 is shown below:


Photo by Ihor Saveliev on Unsplash

In this article we are going to explore the benefits expected to be experienced by households. There is a big noise currently due to the deployment of 5G infrastrcuture and services. However a quick internet search and discussions with non-experts in the field shows that there is not very good understanding about the topic apart from very high level statements such as “faster broadband”, “faster internet connection”, “one after 4G”. My colleague Meghan Pugh has written a warm up 5G introduction. The breaking changes of 5G are aiming to improve our lives from several perspectives. …


Photo by Jack Sloop on Unsplash

In this article we are going to look at recent statistics of open source software utilisation in the United Kingdom. Then we will explore the advantages and finally we will dive into an ongoing 5G Telco project where open source tools are used in a great extent.

According to the Github 2020 report, the UK has been in the top 5 for open source usage outside the US with > 28.6% YoY growth. The total of open source files changed on Github by UK based contributors in 2020 exceed the 80 millions developers with an amazing +33% YoY growth. There…


Photo by Joshua Sortino on Unsplash

Recently I started exploring new waters in my knowledge quest. It’s something I wanted to do for sometime and finally allocated 30' per day to read, understand and organise my thoughts around the benefits of 5G technologies. I am impressed to find out that there are many ways to apply some old/new concepts and meet the current needs of the businesses for machine to machine(M2M) communication and communitication between people.

To connect the dots between this article and my DevOps and Telco Softwarisation series it was great finding out how the CI/CD and DevOps concepts can be glued together and…

Stelios Moschos

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