DEV Community: Konfy

jLovely Lightbend

Konfy — Thu, 03 Jun 2021 10:06:11 +0000

We are pleased to welcome Lightbend on our stage!
Hugh McKee, developer advocate at Lightbend, will present on June 26th about Megaservices. Intrigued? Register on our website to learn more.

We came across Lightbend quite a while ago. If you don't know Lightbend, they are the company behind the Akka toolkit (as well as Scala, Play Framework, Lagom, and others). Hundreds of thousands of Java and Scala developers around the world use these products.
Our first collaboration was at the Scala Love podcast, where Lukas Ritz and Seth Tisue talked about Scala and its compiler's internals. The episode is full of insights, check it out.

In the meantime, learn more about Lightbend, read Hugh's interview, and enjoy previous talks from Lightbenders.

What does Lightbend have to offer?

Two platforms for different flavors of developer experience: Akka Serverless and Akka Platform.

Akka Serverless lets you easily build stateful, high-performance, back-end services and APIs on a powerful serverless platform. It delivers high performance and very low latency in an extremely cost-efficient manner–without worrying about setting up databases, managing state, or ongoing maintenance. Most important: you get your code into production in minutes.
Register for the open beta launch June 16th, 2021!

Akka Platform includes Akka Cloud Platform for AWS and GCP (with Azure coming soon) and Akka Data Pipelines. Together, you get the full power of Akka reactive microservices frameworks and streaming
data pipelines to run on-premise or in the cloud.

Lightbend at jLove 2021

Hugh McKee is a developer advocate at Lightbend. He has had a long career building applications that evolved slowly, inefficiently utilized their infrastructure, and were brittle and prone to failure. Hugh has learned from his past mistakes, battle scars, and a few wins. And the learning never stops. Now his focus is on helping other developers and architects build resilient, scalable, leading-edge systems. He is the author of Designing Reactive Systems: The Role Of Actors In Distributed Architecture

How has your programming style with Java evolved over the past couple of years? What are some of the things that led to the significant improvements?

One of the most significant changes for me has been moving from loops to streams. Also, another change has been using var versus the more traditional and verbose fully typed variable assignment expressions.

Do you have any personal habits around development or self-care that you would like to share with our audience?

Never completely trust your instincts and intuition when you code. One of the most common issues I fight with myself and see in many other developers is not pre-optimizing your code. Get the code working first and then optimize it. One of the worst habits is not trying something new due to preconceived concerns that are not based on facts and experience.

There are Groovy, Scala, Kotlin, and many others in the family of JVM languages. What features do we miss in Java in comparison with other JVM languages? Elaborate.

Semantic density is the fundamental feature that these other JVM languages share that is still missing in Java. That said, the evolution of Java that is focused on reducing code density is one of the most exciting things happing right now.

Are we going to use modules ever? When we create a module, we organize the code internally in packages, just like we previously did with any other project. So why are packages not enough?

Modules are for frameworks IMO. For the most part, we still do not know how to use packages properly. I try to use packages to manage code visibility. That is group code in packages based on the interaction between classes, methods, and functions. Only make something public when something else outside of a package needs access. The default class visibility should be package-private, not public.

Talks we hosted with Lightbend

The focus of the talk Debasish Gosh presented is to emphasize the importance of algebraic thinking when designing pure functional domain models. The talk begins with the definition of an algebra as consisting of a carrier type, a set of operations/functions and a set of laws on those operations. Using examples from the standard library, the talk shows how thinking of abstractions in terms of its algebra is more intuitive than discussing its operational semantics.
The talk also discusses the virtues of parametricity and compositionality in designing proper algebras. Algebras are compositional and help build larger algebras out of smaller ones.
Debasish starts with base level types available in standard libraries and compose larger programs out of them. He takes a real life use case for a domain model and illustrate how he can define the entire model using the power of algebraic composition of the various types. He talks about how to model side-effects as pure abstractions using algebraic effects.
At no point he talks about implementations. At the end of the talk you will have a working model built completely out of the underlying algebra of the domain language.

Akka’s new type-safe APIs graduated from experimental to stable with the release of Akka 2.6. Akka 2.6 was released in November 2019 and represented a major step forward for the project, despite being a minor version tick from 2.5 to 2.6. The new API became the default for documentation, reference projects, and is the base upon which many exciting new features and projects were added to the Akka ecosystem in the following year.

There are too many topics in the Akka 2.6 series to cover in a single talk, but Sean Glover highlights several major developments, such as easier to use APIs for Akka Persistence and Cluster Sharding, a new remoting layer to optimize peer to peer connections in Akka cluster, a new project called Projections to manage readside views in event sourced systems, and the ability to define external shard allocation strategies with Akka Cluster to optimize data locality (i.e. with Alpakka Kafka consumer instances).
He also highlights recently open sourced components that were previously only available to Lightbend customers, such as the Split Brain Resolver for Akka Cluster.

sbt is a build tool that is built on top of a few principles. That simplicity makes sbt very extensible, but it also throws people off because they are not always intuitive. In this talk, Eugene Yokota tries to introduce those core concepts.

He also covers some updates he made in sbt 1.x series.

An active member of the Scala community since 2008, you could have met Seth Tisue at the Scalawags podcast, many conferences, and pretty much any online community around Scala. Having joined the Scala team at Lightbend in 2015, Seth previously used Scala to build the compiler and other tools for NetLogo, an open-source programming language for kids, teachers, and scientists.
Check out the latest Scalawags's episode recorded at Scala Love in the City conference in February 2021.

Development teams in companies like Tesla, Verizon, Starbucks, and PayPal choose Lightbend's products to build the most demanding, globally distributed, cloud native application environments and streaming data pipelines. Many of the Global 2000 turn to Lightbend in support of their most business-critical initiatives. We are pleased to have them at our conferences!
Register jlove.konfy.care.

Reactive jLove

Konfy — Fri, 28 May 2021 21:19:20 +0000

Reactive Systems — as defined by the Reactive Manifesto — is a set of architectural design principles for building more robust, more resilient, more flexible and better positioned to meet modern demands systems.

The idea of Reactive Systems is not new. In 70s and 80s Jim Gray and Pat Helland presented their work on the Tandem System and Joe Armstrong and Robert Virding on Erlang.

However, Reactive is probably one of the less understood terms. It is often abused, and it seems if we want to make something sound cooler, then we can put "Reactive" in front of it.

There are a lot of talks to explain Reactive's primary goals and why it does matter today. But what’s important to understand is that Reactive Systems are not tied to a concrete language/framework, programming model or network interaction style. Instead, it focuses on the principles of such systems, and there are only 8 of them: Stay Responsive, Accept Uncertainty, Embrace Failure, Assert Autonomy, Tailor Consistency, Decouple Time, Decouple Space, Handle Dynamics.

As of now, we are living in a Kubernetes/Container era. Architectural styles like microservices and serverless are growing in popularity.
Data streams that have always been there starting to expand their niche.
Reactive has a lot of essential characteristics to build such systems.

So, Reactive will be a necessary trend for the next five years and let's explore what jLove speakers say about it.

Enabling real time collaboration with RSocket by Sergey Tselovalnikov

Most of the client-server interactions can be expressed with the request-response paradigm, which maps pretty well to HTTP. However, once users start interacting with each other, the request-response paradigm hits its limits as users need to see each other's actions as soon as possible.

This leads to the situation where the backends have to push data to the clients before it's requested. Building such a system is difficult when the number of clients is large since every such a client needs to maintain a connection to the backend. At Canva, we enabled our users to collaborate with each other by introducing services that support bidirectional streaming with RSocket. The talk walks over the challenges that we faced building these services, and the solutions we came up with.

Reacting to an Event-Driven World by Grace Jansen and Kate Stanley

In this session explore how Kafka and Reactive application architecture can be combined in applications to better handle our modern data needs.

Outline:

The need for event-driven architecture with example
Correcting the incorrect assumption that using Kafka give you complete Reactivity and what this really means (i.e. reactive programming, reactive architecture, reactive manifesto)
How to configure Kafka to best enable the cornerstones of the reactive manifesto (with analogies to original example)
How to get started with Kafka
Reactive Kafka frameworks available
Demo application built using Kafka and Vert.x Kafka client and significant changes made when re-architecting this application
Useful resources and helpful links

Reactive Spring by Josh Long

Join Spring Developer Advocate Josh Long (@starbuxman) for a roving tour of how to build more cloud-native, reactive, scalable services with Spring Boot.

Thirst-Quenching Streams for the Reactive Mind by Mary Grygleski

With the advances in multicore hardware and virtualization technologies, and the demand for highly responsive, resilient, and elastic systems and increasingly sophisticated applications, an array of reactive data stream processing libraries have been born to address the needs. Reactive Streams is an initiative to provide a standard for asynchronous stream processing with non-blocking back pressure. This encompasses efforts aimed at runtime environments that include JVM and Javascript, as well as network protocols. So how do the various library implementations of Reactive Streams, such as Spring Reactor, Akka Streams, Vert.x, and RSocket, stack up against each other? And what about Project Loom, and the introductions of continuations and fibers? Will these seemingly promising new features eventually replace reactive? This talk will go into explaining and demonstrating the practical use of reactive streams, then also present some initial analysis on how fibers may potentially become the "new reactive" for the future.

This presentation will go into some details on how streams leverage on the underlying multicore processor to achieve parallelism. It will then explain the push vs the pull streaming model. It will then use a simple use case with code examples to illustrate the different API usages, as well as runtime processing analysis between a few popular Java implementations of Reactive Streams.

Fly like a rocket with Helidon by Dmitry Alexandrov

Good news, everyone! Helidon got a jet engine! Now Helidon is packed with modern, high-tech, James Bond-level features and it flies like a rocket! Also, thanks to a nicely crafted fitness plan, the weight has been reduced and concentration increased - resulting in less RAM consumption and faster waking. Come to my live coding session to learn about all of the new features added in Helidon 2.1; such as GraalVM native image support in Helidon MP, MicroProfile Reactive Streams and Reactive Stream Operators, Helidon DB Client and HTTP Client in Helidon SE. I will also be demonstrating the new command line tool and live-reloading feature which will nitro-boost your development process.

How we got 10x performance in RSocket by Oleh Dokuka

Do you care about performance in Java? Do you want to get a better one? In this talk, I will share what we learned improving the performance of RSocket - Java; Why did we do that?; and of course What you can do to optimize your application.

Scala Love in the City tour

Konfy — Mon, 08 Feb 2021 11:34:44 +0000

The Scala Love in the City conference — a combination of two awesome events, Scala Love Conference and Scala in the City — begins on February 13, 2021, and we hope you’ll be there with us!

This year our conference speakers include some of the most well-known names in the Scala world, including Bill Venners, Jon Pretty, Debasish Ghosh, a reunion of the Scalawags podcast crew, maintainers and users of popular Scala libraries, and of course our keynote speaker, Martin Odersky, the creator of the Scala language.

The conference begins on February 13th, from 9:00 AM to 11:00 PM Central European Time (12:00 AM (midnight) to 2:00 PM Pacific Standard Time in the U.S.). We are going to have two tracks: one for speakers based in Europe/Asia, and one for speakers based in America!

How to Register

Signify Technology and Konfy want to give back to the Scala community and the communities we live in, and therefore we’re not charging for this event. We only ask that any donations you are able to make would be greatly appreciated, and they will go to deserving charities who are helping us all during COVID-19, including NHS and Doctors Without Borders.

You can get your ticket at this EventBrite page.

For more information, the rest of this blog post provides an introduction to what our speakers will be talking about.

Opening Words

On February 13, 2021, at 9:00 AM Central European Time — midnight PST in the U.S. — Oli Makhasoeva and Ryan Adams will kick off the Scala Love in the City conference. Oli (@Oli_kitty) is the CEO of Konfy, a business that organizes online conferences and brings communities together. Ryan (@ryan_signify) is the founder of Signify Technologies, an award-winning Scala recruitment company.

Keynote

The keynote will be given by Martin Odersky, the creator of the Scala language. For anyone who doesn’t know him, Mr. Odersky received his Ph.D. under the supervision of Niklaus Wirth, the chief designer of programming languages like ALGOL, Pascal, Modula, and others. With his work on generics in Java 5, Mr. Odersky was known as “the father of the javac generics compiler.” He’s a professor at EPFL in Lausanne, Switzerland, and for many years his focus has been on the fusion of object-oriented and functional programming, work that led to the creation of Scala.

The presentations

This year’s presentations fall into these categories:

Tooling
Domain Design
Processing at Scale
Functional Programming
Testing
Types
Made with Scala 3
Platforms

The talks are briefly introduced in the sections below, where you’ll also find links for more details about each presentation.
We've also prepared a mind map that can be found here

Tooling

Here are the talks on Tooling:

In Truly Standalone Scala Scripts, Przemek Pokrywka introduces TSK — The Scripting Kit — as a possible solution for Scala scripting. Just write your Scala code, prepend it with a special preamble that invokes a curl script, and you’ll have a solution that works on multiple systems, and is editable with IDEs at the same time.
The CLI of coursier — cs — provides a convenient way to install JVMs, Scala, and tools like sbt, Mill, and Ammonite. In Reproducible Environments for Scala Using Coursier, Alex Archambault demonstrates how it can be used on your local machine, in scripts, and with your CI.
In GitBucket: Open Source Self-Hosting Git Server by Scala, Naoki Takezo discusses the challenges of updating GitBucket, an open source, self-hosting git server, written in Scala, and with over 8,300 stars on Github.

Domain Modeling

Here are the talks on Domain Modeling:

In A Few Tips on Modeling Things in Scala, Mateusz Kubuszok shares some simple and easy-to-implement tips about creating domain models in Scala. Topics include DDD entities, persistence layers, and annotations required by JSON and other libraries.
In Algebraic Thinking for Evolution of Pure Functional Domain Models, Debasish Ghosh, author of Functional and Reactive Domain Modeling, takes a deep dive into the importance of algebraic thinking when designing pure functional domain models, showing how algebras are intuitive as well as compositional.

Processing at Scale

This category includes talks on Big Data, Distributed Systems, Kubernetes, Scalability, and Distributed Tracing:

In Upgrade Tooling with Spark: It’s Not Just for Language Versions, Holden Karau shows how to significantly reduce the pain of updates by using tools to semi-automatically upgrade your Scala (and Python) Spark environments.
In Greyhound: Powerful Pure Functional Kafka Library, Natan Silnitsky shows how Greyhound — an open source, Kafka client SDK wrapper that harnesses ZIO’s sophisticated async/concurrency features — is used by Wix developers in more than 1,500 event-driven microservices.
In Alice and the Lost Pod: Practical Guide to Kubernetes in Scala, Roksolana Diachuk continues her popular “Alice” presentations. This time, Alice needs to bring the pod back home using her knowledge of Scala. Will she be able to discover the link between Scala and Kubernetes to save her friend?
In Scaling Scala at Spotify, Filipe Regadas and Julien Tournay demonstrate how they use Scio — an open source Scala API for Apache Beam and Google Cloud Dataflow — to build data pipelines. Spotify runs thousands of unique Scio jobs, and they discuss scalability in terms of data processed, as well as the number of engineers on your platform.
In One Year with Akka 2.6, Sean Glover talks about a year’s experience with Akka 2.6 and its new type-safe APIs. The talk includes major developments in Akka, and recently open-sourced components that were previously only available to Lightbend customers, including the Split Brain Resolver for Akka Cluster.
In Distributed Application Tracing with Trace4Cats, Chris Jansen demonstrates Trace4Cats, which is both an application library for capturing traces, and a partial tracing system aimed at aggregating, sampling, and forwarding traces to monitoring systems.

Functional Programming

This year’s talks on Functional Programming are:

In Finite State Machines for Functional Software Machinery, Noel Welsh believes that FSMs are one of the simplest models of computation and should be more widely used, so he shows how their simplicity makes them easy to understand, and therefore easy to create and debug.
In HKD: Stems Cells for Data, Oleg Nizhnikov discusses some problems that require boilerplate, macro-converters, or loose typing. He then describes what Higher Kinded Data (HKD) is, and how it transforms into different data shapes.
In OOP Versus Type Classes in Scala, Alex Nedelcu discusses both OOP and ad-hoc polymorphism via type classes. He goes through the pros and cons of each approach, and establishes guidelines for which to pick, depending on the use case.
In An Introduction to Recursion Schemes, Nicolas Rinaudo aims to demonstrate that recursion schemes are far less scary and confusing than they need be. He starts from first principles, refactors his way to proper recursion schemes, explaining all the necessary concepts.
In Cats Effects 3, Daniel Spiewak, Principal Engineer at Disney Streaming Services and primary maintainer of Cats Effects, discusses what’s new in Cats Effects 3.

Testing

Our talks on Testing are:

In Property-Based Testing: Let Your Testing Library Work for You, Magda Stożek demonstrates property-based testing with ScalaTest and ScalaCheck, showing how to generate thousands of test cases with varying data to explore your code’s edge cases, and reduce found problems down to their root cause.
In Who Is Testing Your Tests?, Hugo van Rijswijk demonstrates mutation testing with Stryker4s, a mutation testing library for Scala. This form of testing injects small bugs into your code, and then the question becomes, are your tests good enough to spot the bugs?
In MUnit: Your New Favorite Scala Testing Library?, using live coding, Gabriele Petronella demonstrates MUnit, a testing library for Scala, highlighting MUnit’s most notable features so you can see what makes this little library unique in the testing world.

Types

Here are the talks on Scala 3 Types:

In A Visual Language for Types, Jon Pretty, creator of tools like Fury and Magnolia, provides a visual journey through the Scala 2 and 3 type systems. You’ll see the relationships between the types, and develop an understanding of operations, such as finding the least upper-bound of a pair of types.
In Understand the Type System of Scala 3, Bill Venners, ScalaTest creator and co-author of Programming in Scala, continues where he left off in the 2020 Scala Love conference, where he touched on Scala 3 union and intersection types. This talk covers the more advanced aspects of the type system in Scala 3.

Made with Scala 3

Here are the talks in the Scala 3 and IoT categories:

In Why Scala 3 Will Be Awesome, Piotr Gołębiewski gives you a taste of the Scala 3 future. He uses live coding to demonstrate how certain problems were solved using Scala 2, and how you can now solve them differently with Scala 3.
In Sweet Home Scala 3, Krzysztof Romanowski shows how he’s using Scala 3 on top of the Home Assistant running on Raspberry PI to make his apartment a little “smarter.” He shows how his smart home project works, demonstrating Scala 3 features that improve even a small project.
In A Tour of Contextual Abstractions in Scala 3, Dean Wampler, author of Programming Scala, demonstrates how implicits have been reworked in Scala 3 to make them more intuitive. He demonstrates new constructs like extension methods, given instances with using clauses, given imports, and more.
In Scala 3: Avoiding Macros with inline and derived, Josh Suereth demonstrates how Scala 3 provides a rich set of features that negate the need for most macros. He shows how to use inline methods, tuples, and derived code to create performant and flexible APIs.
In Typelevel’s Road to Scala 3, Lars Hupel outlines some of the history behind Scala 3, and the steps taken in the Typelevel ecosystem to get ready for Scala 3, and keep up with its development.
In DSLs with Scala 3, Jacob Odersky will share some experiences he and his team have had as early adopters of Dotty, as well as some lessons learned while introducing the DSL to complete newcomers of the language.

Platforms

Our “platform” talks are in the subcategories of the JVM, Scala Native, and Android:

Scala is changing, and the JVM is also constantly changing, so in Checking out JVM 12-16, Piotr Przybyl covers the major changes to the JVM and updates to the Java language to show how these changes impact your Scala life.
In A Deep Dive into Scala Native Internals, Wojciech Mazur — a Scala Center team member working on Scala Native — discusses what he has learned as the Scala and native ecosystem worlds come together, including how Scala Native is unique, background on its design decisions, its current status, and the 2021 roadmap.
In Scala on Android, Maciej Gorywoda — who has used Scala professionally for Android app development for four years — talks about how Scala should thrive on Android, but doesn’t. He demonstrates the hacks that are needed to run Scala on Android, and then focuses on recent developments that give hope for a brighter future.

Scala Panel Discussion: Scalawags

The conference also brings together a reunion of the full “Scalawags” crew, which ran a monthly podcast about the Scala language from 2012 to 2016. The reunion includes Josh Suereth, Dick Wall, Daniel Spiewak, Heather Miller, and Seth Tisue.

Party (Spatial Chat)

We're thrilled to continue our tradition of the Hallway Track, powered by Spatial Chat. It allows social interactions – your avatar can move closer to people you want to engage with or move aside if you want to quickly discuss something privately. 🗣️👂

Where to Go Next?

If you want to learn more about the conference, or you’re ready to register, see these links:

The main Scala Love in the City page provides more details on each talk and the conference schedule
Visit the EventBrite registration page to register

We hope to see you there!

A big thank you to our volunteer Alvin Alexander who contributed to this blog post <3