1st React JS Meetup in Athens

Hello fellow Reactors,

September has come and we are back in town. We hope you had a great time during the summer and that you are ready for some (Re)action!

On the 15th of September we are going to have the first ever React JS meetup in Greece!  We are happy to invite you all for an evening full of code, talks and beers. Our venue is the “JAVA” auditorium on the ground floor of “The Hub”, situated in Alkminis 5, in Petralona, close to Benaki Museum in the center of Athens (map).

We are really looking forward to an exciting year ahead and to seeing all of you there!!

Dimitris, George, Stella


18:00-18:30: Welcome drinks and refreshments

18:45-19:00: Introduction to Signal Ocean, Dimitris Tsapoulis

Who we are, our expectations from the meetup and how to set up a strong React community in Greece

19:00-19:45: Introduction to React, Alexander Xypas, Andreas Dimakis

A brief introduction to React that will explain its advantage and present the basic concepts. You will learn through a demo how to boostrap a project to start your development.

20:00-20:45: State Management in React: Redux vs MobX, Lukasz Wisniewski

How does React manage its state? When to use a state manager and when not? What is Redux? How MobX makes our lives easier? All these questions and a few more will be answered by Lukasz in a more in-depth demo of React’s state management. 

Location cost, refreshments and beers are covered by Signal Ocean

All the best, 

React JS Org team

Riding the Streaming Wave with Kafka / Analytics Beyond RAM Capacity with R

Hello wonderful big data developers and enthusiasts. We hope this email finds everyone well!

We are happy to announce our third event for 2017! This time, we welcome Konstantine Karantasis (Software Engineer at Confluent Inc) who will talk about how to build streaming pipelines with Apache Kafka & Confluent Open Source tools. Our second speaker is Alex Palamides (Data Scientist at Clayton Euro Risk) who will present us the Microsoft R Server solution and how to perform big data operations with it. At the end, Landoop engineers will show us their new powerful framework Lenses for Apache Kafka ™</a>, in a mini presentation.

Our venue is the auditorium on the ground floor of ALBA Graduate Business School. The venue has around 110 seats but there is space for people to stand as well. Please RSVP early but do remember to keep your RSVP up to date to allow other people who would like to attend a chance to come if your plans change.

We are really looking forward to seeing you there!

<a href=”https://www.linkedin.com/in/adrianosdadis”>Adrianos | Euangelos | Stavros


1st Talk:

Title: Riding the Streaming Wave DIY style: Using & Building Kafka Connect Plugins with Confluent Open Source

Stream processing is changing the way companies organize their data systems architecture and respond to events critical to their business. In this talk, we’ll review how software available with Confluent Open Source can help you hit the ground running when integrating your data systems to Apache Kafka. We’ll see how Kafka Connect API can be leveraged to do the heavy lifting at scale and how new tools in Confluent Open Source help you use, test and even develop Kafka Connect plugins.

Konstantine Karantasis is a Software Engineer at Confluent, Inc. working from Palo Alto, CA. He’s the main contributor to open source projects such as the Confluent S3 Connector, classloading isolation in Apache Kafka Connect, Confluent CLI and many more. Previously, he built open source web-services for big data at Yahoo and did HPC research at the University of Illinois at Urbana-Champaign. Konstantine holds a Ph.D. from the University of Patras.

2nd Talk:

Title: Analytics Beyond RAM Capacity: The Microsoft R Server Solution

R is a language and environment for statistical computing and graphics which was developed at Bell Laboratories and is considered one of the default choices for a data scientist. However as by design all computations take place in RAM, it suffers from memory limitations in big data applications. Microsoft R Server (MSR) on the other hand by utilizing RevoScaleR package capabilities follows a different approach; Datasets are stored on the disk and computations are performed into chunks of data, therefore data is inherently distributed. However as most open-source R algorithms require the whole data frame loaded into RAM, the first challenge is to process distributed data indirectly utilizing open-source R algorithms. On the other hand in the MSR most common data operations (manipulation and analysis) are supported by counterpart functions. Moreover the inherently parallel processing makes deployment to a production environment such as SQL Server or on HDFS relative easy. MSR runs either in standalone mode, either within the SQL Server branded as R Services.

Dr. Alex Palamides is a data scientist in Clayton Euro Risk, deploying risk and marketing models in the banking sector mainly programming with R. Previously he was with IRI (EU and US), with the European Space Agency and in various consulting roles. He holds a BSc in Electronic and Computer Engineering from the Technical University of Crete and a PhD in Computational Statistics from the University of Peloponnese.

Mini presentation:

Landoop will give a short introduction and presentation.

Landoop last week, during the Kafka Summit (San Francisco) announced their new powerful framework Lenses for Apache Kafka ™ (a visual interface for interactive queries on Kafka topics via Kafka SQL).

Landoop is a company based in London, Amsterdam and Athens.


7:00-7:15 – Socialising

7:15-7:20 – Welcome

7:20-8:05 – 1st Talk

8:10-8:55 – 2nd Talk

9:00-9:10 – Landoop mini presentation

9:10++  – Drinks and Pizzas


A massive thank you to our sponsors:

Wanna Join?

We are always looking for speakers for our meetups. If you would like to give a talk this year please contact with Adrianos, Euangelos or Stavros.

Kotlin & The journey towards a platform agnostic code base

Hello everyone

We are really excited to announce our new gathering at GDG Android Athens, that will take place on 11th of October at The Cube.

In our new meetup, Antonis from Advantage FSE will introduce us to Kotlin, while our second speaker Alex from Novoda team will discuss how to move towards platform agnostic development.

Special thanks to Advantage FSE (http://www.afse.eu/) for sponsoring the space, e-food.gr (https://www.e-food.gr) for the pizzas and Pollfish (http://www.pollfish.com/) for the beers!

Important: Please RSVP to this meetup only if you will attend, in order to have a rough estimation of the number of people that eventually will come and therefore be able to properly prepare and arrange the meetup.



1) Title: Is this Swift for Android? A short introduction to the Kotlin language

Description: Do you like Java but wish you didn’t have to write so much boilerplate code? Kotlin is now an officially supported language for Android and has an answer for this. Kotlin aims to address many of the pitfalls that are common with Java development, while making your code more concise, safe, and expressive. It is also 100% interoperable with Java and can be mixed in the same project.

Bio: Antonis Lilis (http://www.linkedin.com/in/alilis), Mobile Solution Architect @ Advantage FSE.

2) Title: The journey towards a Platform agnostic code base

Description: Sharing the same codebase across different platforms is the number one dream to many developers. With Kotlin being the new official language for Android and it being already used on other platforms such as the web (and eventually iOS), it is the perfect time to talk about sharing code across platforms.

In this talk Alex will go through the steps he is following to achieve the cross-platform dream in his side project, Memento Calendar, from start to end of a feature. We are going to see how to structure your project so that your business logic is separated from platform specific code, how to write platform agnostic features and how to test them.

Bio: Alexandros Stylianidis (http://alexstyl.com) is a Product Designer at Novoda London with a strong background in engineering. He loves talking design and tech and has been into Android since 2.2 Froyo.

P.S. We have an open invitation for anyone interested to speak at the next or any future meetup. You can easily do that online in this link (https://docs.google.com/forms/d/e/1FAIpQLSfcNuAkkYBRjRz-JVXox0ckboPeUI5orh9EvMw1_tfe9IdsOQ/viewform?c=0&w=1&usp=send_form).

We have also an open invitation for anyone that would like to sponsor GDG Android Athens Meetups and make everyone happy either by hosting an event or bringing the pizzas or beers!

Join or Follow us to stay up-to-date with the latest news of the community at:

Website: http://gdgandroidathens.com/

Slack: https://slofile.com/slack/gdgandroidathens (https://slofile.com/slack/gdgandroidathens)

Twitter: https://twitter.com/gdgandroidATH (https://twitter.com/gdgandroidATH)

Youtube: https://goo.gl/WPsNEL

Facebook: https://www.facebook.com/GDGandroidAthens

14th Bitcoin and Blockchain Tech Meetup

Το πρόγραμμα για την 14η συνάντηση θα είναι:

18.30 – 19.30 Εισαγωγή στο Bitcoin για αρχάριους (μη τεχνική) — Κώστας Καρασάββας
19.30 – 19.45 Διάλειμμα (δικτύωση / γνωριμίες)
19.45 – 21.00 Πως δουλεύει το Bitcoin — Κώστας Καρασάββας
21.00 – 21.30 Συζήτηση / δικτύωση / τέλος

Η πρώτη παρουσίαση είναι η ίδια που έγινε στις προηγούμενες συναντήσεις οπότε όποιοι έχουν κάποια εμπειρία μπορούν να έρθουν κατευθείαν στις επόμενες ομιλίες (μετά τις 19.30). Πάντα έχουμε νέους χρήστες και συνήθως κάνουμε τα εισαγωγικά της τεχνολογίας.

Μετά την εισαγωγική ομιλία θα αρχίσουν μια σειρά από τεχνικές ομιλίες σχετικά με το Bitcoin και πως δουλεύει. Σε αυτή τη συνάντηση το θέμα μας θα είναι μια επισκόπιση του τι γίνεται πραγματικά όταν γίνεται μια συναλλαγή με Bitcoin, από τη δημιουργία της συναλλαγής μέχρι του να γίνει μέρος του blockchain. Έχετε υπόψη ότι οι ομιλίες είναι τεχνικές (επίπεδο πανεπιστημίου αλλά λίγο πιο απλουστευμένα). Θα υπάρχει αρκετός χρόνος για ερωτήσεις οπότε μη διστάσετε να το παρακολουθήσετε ακόμα και αν δεν έχετε πολύ τεχνικό υπόβαθρο.

Το περιβάλλον είναι χαλαρό και θα υπάρχουν πολλές ευκαιρίες για να μάθουμε και φυσικά για να γνωριστούμε.

Ελπίζω να σας δω στη συνάντηση! 


The agenda for the 14th meetup is (presentations are in Greek):

18.30 – 19.30 Introduction to Bitcoin for beginners (non-technical) — Kostas Karasavvas
19.30 – 19.45 Break (networking)
19.45 – 21.00 How Bitcoin works — Kostas Karasavvas
21.00 – 21.30 Discussion / networking / end

The first presentation will be the same as in the last meetups so people with some experience may prefer to skip it and come directly for the later presentations (after 19.30). We always have new members so we typically to do the introductory talk to help them join our community.

Following the introductory talk we will begin a series of technical talks concerning Bitcoin and how it works behind the scenes. For this meetup the subject topic is an overview of how bitcoin works, from the creation of a transaction to becoming part of the blockchain. Note that the technical talks will be increasing in difficulty and are University-level talks (slightly simplified). There will be a lot of time for questions so do not be intimidated if you are not very technical.

The environment is casual and there will be plenty of opportunities to learn and more importantly get to know each other.

Hope to see you there! 

REST in Peace – Modern API Design with GraphQL

GraphQL is a new and open-source technology that provides a more efficient and flexible alternative to RESTful APIs. It was developed and open-sourced by Facebook and is now maintained by a large community of individuals and organisations from all over the world. In this talk, Nikolas Burk will give an introduction to GraphQL and explain how it compares to REST. Furthermore, he’ll provide context on some architectural use cases for GraphQL and highlight major concepts that you should be aware of. He will also demonstrate how to get started quickly with your own GraphQL server using Graphcool.

We will also do an introduction to graphql-dotnet.

.NET CONF 2017 Thessaloniki local event

Microsoft will be streaming .NET Conf for three days live around the world. 

Join us for the .NET Conf local event.


19:00 Get Started with ASP.NET Core 2.0 (Channel 9)

In this session we will start with a new ASP.NET Core 2.0 web application and go through fundamentals such as Configuration, DI, and Logging. We will start by going through the Program.cs and Startup.cs talking about all the features that are shown there. By the end of this session you should have a good grasp of how ASP.NET Core works.

19:45- 20:30  Turning software into computer chips – Hastlayer with Zoltan Lehoczky (Skype)

Software is flexible, specialized hardware is extremely fast. So why not write software, then turn it into a computer chip? This is what Hastlayer does by transforming .NET software into electronic circuits. The result is faster and uses less power while you simply keep on writing software. You may not be able to tell just by looking at it but behind some function calls now actually embedded hardware is working! (You wonder how? Check out what FPGAs are!) In this demo-packed session we’ll get an overview of what Hastlayer is, why it is useful for developers like you and how to write Hastlayer-compatible software.

20:30 Bojan Vrhovnik (Skype) will talk about Azure App Service: the best place to host your .NET Apps.

Experience how App Service makes your life easier as a .NET developer by providing the most powerful, flexible and scalable platform to host your apps in the cloud and focus on the code, not the infrastructure. See what others are already hosting in App Service and understand some of the best patterns and practices for hosting different kinds of apps like CMS, marketing sites, High Scale applications, LOB apps, etc.. Learn about some of the premium features offered by the platform geared towards enterprise customers and hybrid cloud scenarios.

.NET + QA & Testing United. Creating a Test Automation Framework

What is the purpose of a Test Automation Framework? What challenges does it solve for the development team? Learning how to use a tool like Selenium to create automated tests is not enough to be successful with an automation effort. You also need to know how to build an automation framework that can support creating tests that are not so fragile that they constantly break. This is the real key to success in any automation effort.In this meetup we’ll find out how to create a test automation framework using selenium & .NET following the page pattern.

Presentation by John Pourdanis and Stratos Kourtzanidis.