Best Rated Java Talks

Riga Dev Days
3 min readJan 22, 2019


There’s always a dilemma at the conference which talks to visit, how to make a right room decision. Thanks to video records and after the conference ratings from the session visitors, we can fix this issue and tell for sure which sessions were definitely worth attending. Here, we gathered best rated Riga Dev Days videos 2016–2018.

Java is in the air!

#5 Functional data structures in Java, by Oleg Šelajev

Rating 4,55/5

In this presentation, Oleg shows several purely functional data structures implemented in Java 8 and discusses why are they efficient and when you might prefer these ones to the data structure built-in into the JDK.

Watching this session, you’ll feel more comfortable with functional data structures and will be more likely to succeed using functional programming for problems that involve data crunching in the future.

#4 Turbo Charge CPU Utilization in Fork/Join Using the ManagedBlocker, by Heinz Kabutz @Heinzkabutz

Rating 4,61/5

Heinz devoted the session to Fork/Join, which is a framework for parallelizing calculations using recursive decomposition, also called divide and conquer. Also in this talk, he demonstrates the issue when a significant number of threads are blocked, decreasing CPU utilization, and offers a solution in the form of the ManagedBlocker combined with the Fork/Join.

#3 How (not) to use Reactive Streams in Java 9, by Jacek Kunicki

Rating 4,76/5

In this session, Jacek is going through the basic concepts of reactive stream processing and shows how (not) to use the APIs included in JDK 9+. Plus he discusses possible directions in which JDK’s Reactive Streams support may go in future.

#2 Vavr(ex-Javaslang) — Functional Java Done Right, by Grzegorz Piwowarek

Rating 4,77/5

The second place takes the session of Grzegorz explaining how Java 8’s lambdas empower us to create wonderful APIs. Vavr allows diving deeper into the world of functional programming by providing persistent data types, immutable collections, and functional control structures. Also during this presentation, you can recall Java8’s downsides and explore how Vavr’s Scala-inspired features fill-in the gaps.

#1 JUnit 5: Next Generation Testing on the JVM, by Nicolai Parlog @nipafx

Rating 4,84/5

Nicolai shows how to write tests with JUnit 5, walks through the changes compared to JUnit 4, expanded on dynamic tests and the extension model. Also, he presents the new architecture and discusses compatibility with previous JUnit versions, IDEs, and other testing tools.


An introduction to Kotlin by example, by Dmitry Kandalov

Rating 4,86/5

Where Java is, there is Kotlin!

Dmitry thinks that Kotlin is what Java 9 should have been if it was written from scratch. The session is mostly live coding demo based on small programming problems written in Kotlin. It starts with “hello world” and continues to more complex examples ending with Kotlin puzzlers.

Maybe after this video, you’ll say “Hello, Kotlin! Goodbye, Java!” or not?

See, what Java sessions are announced in the program of Riga Dev Days 2019 and join one of the biggest meeting points for developers in the Baltic States!



Riga Dev Days

Tech conference and the annual meeting point of developers in Baltic States. 29–31 May, Riga