Scala Java

Open-source Scala projects categorized as Java

Top 23 Scala Java Projects

  • Apache Spark

    Apache Spark - A unified analytics engine for large-scale data processing

    Project mention: Uber Interview Experience/Asking Suggestions | | 2023-02-01

    One place to look are the projects repo's and docs, once you have a good idea of how the system is architected poking around pieces of the codebase can be helpful in letting you really understand their internals. I personally enjoy going through spark repo and trino repo and the documentation for both projects is decent and can answer many of your questions.

  • Play

    Play Framework

    Project mention: Why I selected Elixir and Phoenix as my main stack | | 2023-01-21

    In university I learned a bit of Java, so maybe I could use it professionally I guess?. There were many options to choose from. DropWizard, Spark, Play Framework. But the more documented one in the internet I found was Springboot, besides there were some courses in spanish and some friends that knew something about Springboot, so I give it a chance.

  • InfluxDB

    Build time-series-based applications quickly and at scale.. InfluxDB is the Time Series Platform where developers build real-time applications for analytics, IoT and cloud-native services. Easy to start, it is available in the cloud or on-premises.

  • Finagle

    A fault tolerant, protocol-agnostic RPC system

    Project mention: Pretty incredible thread where Elon confuses how GraphQL works, thinks the Android client itself is making one thousand requests, and then publicly fires an employee who corrects him. | | 2022-11-14

    Bro it's their fucking project lol

  • Lagom

    Reactive Microservices for the JVM

  • Mill

    Your shiny new Java/Scala build tool!

    Project mention: Why is Scala a mildly loved language? | | 2022-06-24

    It was my case, but made my life easier

  • Reactive-kafka

    Alpakka Kafka connector - Alpakka is a Reactive Enterprise Integration library for Java and Scala, based on Reactive Streams and Akka.

  • Kamon

    Distributed Tracing, Metrics and Context Propagation for applications running on the JVM

  • SonarQube

    Static code analysis for 29 languages.. Your projects are multi-language. So is SonarQube analysis. Find Bugs, Vulnerabilities, Security Hotspots, and Code Smells so you can release quality code every time. Get started analyzing your projects today for free.

  • adam

    ADAM is a genomics analysis platform with specialized file formats built using Apache Avro, Apache Spark, and Apache Parquet. Apache 2 licensed.

    Project mention: Advanced Scientific Data Format | | 2022-09-30

    We presented using Parquet formats for bioinformatics 2012/13-ish at the Bioinformatics Open Source Conference (BOSC) and got laughed out of the place.

    While using Apache Spark for bioinformatics [0] never really took off, I still think Parquet formats for bioinformatics [1] is a good idea, especially with DuckDB, Apache Arrow, etc. supporting Parquet out of the box.

    0 -

    1 -

  • bloop

    Bloop is a build server and CLI tool to compile, test and run Scala fast from any editor or build tool.

  • Scrooge

    A Thrift parser/generator

  • guardrail

    Principled code generation from OpenAPI specifications

    Project mention: Scala Library To Generate Case Classes for JSON | | 2022-08-16

    You may have some luck with Guardrail

  • akka-http-session

    Web & mobile client-side akka-http sessions, with optional JWT support

  • AkkaGRPC

    Akka gRPC

  • java-webauthn-server

    Server-side Web Authentication library for Java

    Project mention: Software and drivers | | 2022-10-24

    If you need them to use one of a set of trusted authenticator models, then you need attestation. Your authentication servers will need to compile a set of acceptable attestation root certificates, and require that all enrolled credentials have a valid attestation statement that correctly chains to one of those trusted root certificates. Yubico provides libraries to help with this for Python and Java You can provide the devices or let users self-source one on the list of acceptable models. Your webapp will also need to guide users to use the correct authenticator if they attempt to use an untrusted one. Note that this will only let you verify an authenticator model, not individual YubiKeys (i.e., not on serial number level).

  • SwayDB

    Persistent and in-memory key-value storage engine for JVM that scales on a single machine.

  • Play WS

    Standalone Play WS, an async HTTP client with fluent API

    Project mention: Code in jar dependency is packed as java code and can not be used as normal Scala dependency | | 2022-05-04

    Take a look at build.sbt. it is a scala lib built with sbt-assembly to shade dependencies and avoid binary incompatibility. That is the only reason to build a lib with sbt-assembly.

  • kukulcan

    A REPL for Apache Kafka

  • tscfg

    Boilerplate-free, type-safe access to configuration properties in Java and Scala

    Project mention: Benchmark of Java Configuration Libraries | | 2022-06-14

    While you covered a lot of libraries, there are others, more or less used: - - - - - - -

  • clojure-news-feed

    evaluating various technologies by implementing a news feed micro-service

    Project mention: How do you decide which language/tech stack you invest learning? | | 2022-08-14

    Your question is interesting to me. As a software architect, I study various tech stacks and programming languages. I concentrate mostly on open source and microservice architectures. I usually start with implementing the same feature identical rudimentary news feed microservice. Over time you start to see the similarities and differences between the various implementations. I blog about this over at and the source code can be found in

    You are looking for a decision on what programming language and tech stack to learn next based on career mobility. Here are some questions to consider.

    What kind of company are you most interested in working for? Think about the size of the company. Is it in a growth market or is profitability more important? Is it a technology company? Does the CEO view technology as a profit center or a cost center? Do they have a CTO? If they do, then who does the CTO report to, the CEO, the CIO, or the COO?

    What kinds of programming languages and tech stacks are on the career pages for the kinds of companies that you are most interested in? Different kinds of companies tend to cluster around different tech stacks. There are other factors to filter for such as how deeply do they embrace remote work or commute distance to where you currently live or are willing to move to.

    These are lagging indicators. They are going to be more accurate than leading indicators but that also might indicate that whatever you learn next based on these factors might have a shorter shelf life.

    Finally, you should ask yourself what about your current programming language do you like? Try to pick something that you would also like. The Go programming language was originally invented as a better C and is enjoying some marketability right now. Maybe that would be something to look at.

  • grpc-scala-sample

    translated from grpc java examples with ScalaPB

  • bazel-multiversion

    Bazel rules to resolve, fetch and manage 3rdparty JVM dependencies with support for multiple parallel versions of the same dependency. Powered by Coursier.

  • figlet4s

    ASCII-art banners in Scala

  • opal

  • SaaSHub

    SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives

NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020). The latest post mention was on 2023-02-01.

Scala Java related posts


What are some of the best open-source Java projects in Scala? This list will help you:

Project Stars
1 Apache Spark 34,911
2 Play 12,317
3 Finagle 8,481
4 Lagom 2,630
5 Mill 1,834
6 Reactive-kafka 1,398
7 Kamon 1,367
8 adam 944
9 bloop 830
10 Scrooge 768
11 guardrail 484
12 akka-http-session 444
13 AkkaGRPC 421
14 java-webauthn-server 313
15 SwayDB 277
16 Play WS 214
17 kukulcan 113
18 tscfg 96
19 clojure-news-feed 79
20 grpc-scala-sample 64
21 bazel-multiversion 41
22 figlet4s 33
23 opal 23
SaaSHub - Software Alternatives and Reviews
SaaSHub helps you find the best software and product alternatives