Serverless .NET using AWS Lambda: from zero to hero

Serverless challenges long-held beliefs about applications architecture and transforms the way we do business by providing a much cheaper
alternative to the traditional computing model of provisioning and managing our own servers.

Additionally, serverless applications scale automatically to precisely match the size of our workload.

AWS Lambda has been the first such managed service to launch by a Cloud provider back in November 2014 and it has changed the landscape since, leading other Cloud providers to follow suit.

Creating a C# Lambda function or application with .NET Core 2.x as its runtime has been available since January 2018 and in this
meetup we’ll explore lessons learned from the .NET serverless trenches in the months since.

We’ll start by going over some of the common use cases for Lambda functions, triggers and targets as well as limitations.

We will then go on to build an enterprise-grade Lambda function by starting small and then refactoring towards well-known Object-oriented programming best practices with an eye for resiliency and maximizing code re-usability.

Lastly, we will look into the available tooling options when it comes to managing a complete DevOps life-cycle of a Lambda function; starting with our IDE all the way to CI/CD pipelines.

Panos Tsilopoulos is a certified AWS DevOps professional.

Hacktoberfest in Larissa!

Οι Larissa Developers γιορτάζουν το Hacktoberfest!

Αν είσαι λάτρης του ανοιχτού λογισμικού και θα σου άρεσε να συνεισφέρεις σε ένα project που θα βοηθήσει την κοινότητα μας και θα κάνει τα meetups μας καλύτερα, σε περιμένουμε το Σάββατο 27 Οκτωβρίου στον χώρο του Λίντο για να γιορτάσουμε μαζί τον μήνα του ελεύθερου λογισμικού και να ξεκινήσουμε το Prizy!

Be a part of the open source celebration by contributing to Prizy, a Larissa Developers project that will help our meetups become better! If that idea sounds fun to you, come and meet us on Saturday 27th of October and join our Hacktoberfest celebration!

Technologies that will be used in the project:
⚈ Python – Django – Django REST
⚈ JavaScript – React Native

** Prerequisites **
⚉ Please read our Ηacktoberfest guide ( and the Ηacktoberfest Events Code of Conduct ( before attending.
⚉ Be ready to have fun!

12:00 – 12:30 Team bootstrapping and project pep talk
12:30 – 16:00 Happy coding!

P.S: After the pep talk, you are free to leave or work from home.Please bring your laptop if you want to stay and work with us!

Software Testing Antipatterns & Selenium for Java Devs

Thessaloniki Java Meetup and Thessaloniki Software Testing & QA Meetup join their forces to discuss about software testing anti-patterns and do a brief introduction to Selenium for Java developers.

1. Testing nowadays is a serious thing with the agile transformation of many companies that want to have fast feedback to their sprints. This challenge needs collaboration of developers and testers so we will do an introduction of the most famous framework for end-to-end testing and we will discuss how object oriented principles can apply to a test automation framework.
Mr. John Pourdanis ( ) will present some Selenium samples for Java developers (and testers) with some tips for design a maintainable test automation framework.

2.In the second talk we will see the top 10 common pitfalls for testing. We will talk about unit and integration tests, what needs to be tested (and what doesn’t). We will talk about testing state vs testing behaviour and even mention one of the most controversial topics ever: code coverage (and how much is enough). Finally we will see how CI/CD and solid integration tests can play well together.
Mr. Kostantinos Kapelonis ( ) is a Software Engineer who loves clean and compact code, simple solutions and modular distributed systems. He hates feature creep, over-engineering, XML gluttony and monolithic systems. He has a soft spot for code Quality and build systems.

We will give away also 2 Voxxed Thessaloniki free tickets and 2 Jetbrains subscriptionhs

Software development at CERN

This presentation will provide an introduction to CERN and its operations, focusing on software development and the various opportunities available.

Afterward there will be a dive into the development process which is followed on the applications, presenting the various technologies, frameworks and practices followed.

Moreover we will dive into the Accelerators Logging Service one of the major big data projects at CERN and will demonstrate data analysis with Spark on Hadoop (Jupyter).

Last but not least we will conclude with the movement towards integrating all these systems together.

In the presentation three CERN developers (Anti, Starhis and Grigoris) as well as one Team Leader (Chris Roderick) will take part.

The presentation’s outline is the following:

1. A small introduction and the agenda of this presentation (Anti Asko)
2. A small introduction to CERN, Beams Department, Controls Group and Data Services, different opportunities at CERN (TECH, PJAS, FELLOW, STAFF). (Chris Roderick)
3. The development process which is followed on the applications (technologies, ACW framework, development practices). (Stathis Tantalidis)
4. A dive into the “Accelerators Logging Service”, one of the major big data projects at CERN. (Grigoris Avgitidis)
5. Will conclude with the movement towards integrating all these systems together. (Anti Asko)

Talkers: Chris Roderick, Stathis Tantalidis, Grigoris Avgitidis, Anti Asko

14th WordPress Larissa Meetup

Η Ελληνική Κοινότητα του WordPress δίνει σταθερά το παρόν μηνιαία και ο Εκπαιδευτικός Οργανισμός Όμηρος ανοίγει τις πόρτες του νέου υπερσύγχρονου κτιρίου του που στεγάζει το ΙΕΚ Όμηρος και το Aegean College στην Πατρόκλου 14, την Τρίτη 23 Οκτωβρίου 2018, στις 19:00, για να φιλοξενήσει στις αίθουσές του την πρώτη συνάντηση της Ελληνικής Κοινότητας του WordPress στην πόλη της Λάρισας για τη φετινή χρονιά.

Στην πρώτη μας συνάντηση για τη χειμερινή περίοδο[masked], η Ευαγγελία Παππά, web publisher, θα μας μιλήσει για το WordPress και τις κοινότητες χρηστών, τις διοργανώσεις και τον τρόπο να συνεισφέρει κανείς αλλά και το γιατί.

> WordCamps, meetups και άλλα δαιμόνια! – Με την ευγενική χορηγία της Ελληνικής Κοινότητας του WordPress

Ο Χρήστος Ζιώγας, iOS Software Engineer στην εταιρία Authentiq, θα μας μιλήσει για τα plugins και τον τρόπο λειτουργίας τους, καθώς επίσης και για τα WP hooks, ενώ θα μας δείξει τον τρόπο να δημιουργήσουμε ένα απλό plugin χρησιμοποιώντας 1-2 WP hooks.

> WordPress hooks and plugin development

12th Athens Laravel Meetup @stonesoup -> 30/10/18

Η επόμενη μας συνάντησή στην Αθήνα θα πραγματοποιηθεί την Τρίτη 30 Οκτωβρίου 2018 στο φιλόξενο “Stone soup”.

Η ώρα προσέλευσης είναι στις 18:30, ενώ η ομιλία θα ξεκινήσει στις 19:00.

Η ομιλία θα έχει θέμα “Version Controlled Models” και θα παρουσιαστεί από τον Δημήτρη Σαββόπουλο. Θα δούμε το event sourcing implementation που χρησιμοποίησε ο Δημήτρης για τις παραγγελίες που γίνονται στο marketplace

Ο στόχος; Να γνωρίζουμε το state της εφαρμογής μας ανά πάσα στιγμή δημιουργώντας ένα ελαστικό σύστημα που μπορεί να καλύψει όλες τις μελλοντικές μας ανάγκες.

Σας περιμένουμε!

Μετά την ομιλία θα συνεχίσουμε στο μεζεδοπωλείο “ΑΜΑ ΛΑΧΕΙ – ΣΤΗΣ ΝΕΦΕΛΗΣ” για μπίρα και μεζέ.

Let us introduce ourselves and let’s talk about Arch Linux

Είναι η πρώτη συνάντησή μας για τη νέα χρόνια. Θα καλωσορίσουμε τα νέα μέλη, θα παρουσιάσουμε το πλάνο μας για τη νέα χρονιά, το πλούσιο πρόγραμμα διαλέξεων που ετοιμάζουμε και θα συζητήσουμε για το πως θα οργανώσουμε ένα καλύτερο hackathon!

Αλλά δε θα κάνουμε μόνο αυτό. Το μέλος μας Δημήτρης Κιζιρίδης θα μιλήσει για τη διανομή Arch Linux!

Πιο συγκεκριμένα θα γίνει demo εγκατάσταση και χρήση του Arch Linux σε VM περιβάλλον, καθώς και παρουσίαση διάφορων Shell, εισαγωγή στα unit files και εξήγηση του systemd.

Θα γίνει παρουσίαση του pacman και αντιπαράθεση με το aptitude του Ubuntu/Debian. Τέλος θα γίνει παρουσίαση διάφορων εργαλείων προς διευκόλυνση όσων ζουν στην κονσόλα (terminal) και εξήγηση των dotfiles.

Δεν απαιτούνται ιδιαίτερες γνώσεις linux μια που η παρουσίαση θα απευθύνεται σε νέους χρήστες!

Κωδική ονομασία: Στέφανος Χίος

ΑΠΟΚΛΕΙΣΤΙΚΟ! Μόνο στο PyThess της Παρασκευής:

KUBERNETES: Αυτός ο άγνωστος. “Βόμβα” Κοροκυθάκη: Παρουσιάζει πώς να κάνετε deploy flask applications στο Kubernetes και εξηγεί πώς δουλεύει για να μην πέσουν τα Βαλκάνια στα χέρια των Ρώσων! Τώρα θα “φας” καλά: Γελάνε και οι κότες με όποιον κάνει deploy σε physical servers. Νέο επεισόδιο στο σίριαλ των devops. Αποκάλυψη σοκ, όλες οι μεγάλες εταιρείες μετακομίζουν τα applications τους στον κολοσσό της Google: Είναι έτοιμο το Kubernetes να δεχτεί production deployments; Αυτά και άλλα πολλά στην πρώτη παρουσίαση του PyThess της Παρασκευής.

Έκτακτο: Κίνδυνος στα dynamic websites! Ιοί και Ρώσοι χάκερς ταλανίζουν το WordPress. Πώς να προστατευτείτε από τη Ρωσική εισβολή με static websites. Γιατί ο Trump θέλει να στήσει το site της Правда σε WordPress. Ποιο είναι το πρόβλημα, πώς φτάσαμε ως εδώ και τι θα γίνει τώρα. Ο Τέλης Κίττας μας αποκαλύπτει πώς να φτιάξετε το δικό σας στατικό site σε Lektor και να το κάνετε εύκολα deploy στο Netlify. Όλα τα μυστικά που η μασονία δε θέλει να ξέρετε. Συγκλονιστικό βίντεο: Έκανε deploy website updates μόνο με ένα git push. Μα που πήγαν τα deployment steps;;;;

Μόνο την Παρασκευή 12 Οκτωβρίου 8 η ώρα το βράδυ στο Coho. Σοβαρευτείτε γιατί σας πήρανε χαμπάρι.

Special Event: The Searching Movie

This time we go to the movies, for a very tech related movie.

After David Kim (John Cho)’s 16-year-old daughter goes missing, a local investigation is opened and a detective is assigned to the case. But 37 hours later and without a single lead, David decides to search the one place no one has looked yet, where all secrets are kept today: his daughter’s laptop. In a hyper-modern thriller told via the technology devices we use every day to communicate, David must trace his daughter’s digital footprints before she disappears forever.


Ethereum Plasma and Bitcoin Scripting

First an announcement: On 19-20 of November the next Voxxed Days developer conference will take place in Thessaloniki! This is a very successful and high-profile conference for developers and is taking place at our home town! You will find more information at

They were kind enough to offer free tickets for the members of our meetup. During the break we will make a draw and two lucky members will be able to attend the conference for free.

The agenda for the meetup is:

19.00 – 20.00 Introduction to Plasma for Blockchain Scalability — Georgios Konstantopoulos
20.00 – 20.15 Break
20.15 – 21.15 Introduction to Bitcoin Scripting — Kostas Karasavvas
21.15 – 21.30 Discussion / networking / end


– Introduction to Plasma for Blockchain Scalability
Plasma is a technique which is used to increase Ethereum transaction throughput, while maintaining network decentralization and security. We focus on the variant of Plasma called Plasma Cash, which allows for highly performant sidechains in production, today. We discuss Plasma Exits and Challenges as well as explore the User Interface choices for Plasma Apps. We go over the challenges encountered during the development and final implementation of a Plasma chain and contract. The presentation will highlight the advantages and disadvantages of using Plasma Cash, as well as practical examples of Plasma for Non Fungible Tokens and gaming. Finally, we’ll talk about edge-cases such as griefing attacks, and future work towards making Plasma implementations more efficient, such as fast exits through liquidity providers, coin checkpointing through Plasma XT and arbitrary coin denominations through Plasma Debit. The audience is expected to walk away with a detailed understanding of how Plasma Chains should be built as well as the inner workings of the Plasma Cash technique. More experienced individuals who understand but are not following Plasma actively are expected to walk away with an overview of the current status of Plasma research and development, and motivated to tackle the existing open research problems.

– Introduction to Bitcoin Scripting
In this talk we go deeper into what constitutes a transaction and how scripting is used to lock bitcoins and later unlock them to spend them. We then provide several examples on how to create transactions by calling a node’s API or programmatically.

Short Biographies of presenters:

– Georgios is leading Plasma Research at Loom Network. He holds a MEng degree in Electrical & Computer Engineering. He previously worked at Honda where he did his thesis on metering and billing of energy with smart contracts. He has also worked as an independent smart contract auditor and pentester. He is interested in all-things-blockchain as well as cryptography, IoT, infosec and autonomous vehicles.

– Dr. Konstantinos Karasavvas is a computer scientist with 20+ years of experience. He has worked in academic research in multi-agent systems and service-oriented architectures for about a decade and following that he worked in the industry as a software architect and engineer for several years and in several domains from bioinformatics to finance. Currently, and for the last 5 years, he is focused solely on blockchain technologies as a technical advisor. He is teaching and leading several research and development teams in both academia and industry. He is also an active member of local Bitcoin communities, organizing meetups and presenting in events.

The environment is casual and there will be plenty of opportunities to learn and more importantly get to know each other. After the event everyone is welcome to one of the nearby cafeterias to get to know each other.

Hope to see you there!