Topics / #concurrency

Concurrency projects on GitHub

Concurrent and parallel programming techniques

As of , the most-starred Concurrency projects on GitHub are JavaGuide (159.1K stars), advanced-java (79.2K stars) and guava (51.9K stars). GitHub.Locker tracks 93 Concurrency repositories with 1.8M stars combined. The fastest-growing on October 16 was bend, with +44 stars in a day.

93Projects
1.8MStars in total
+289Stars in a day
Browse in the catalog →github.com/topics/concurrency ↗

Hot right now

Most stars gained in a day · Oct 16

+44

bend

bendlang/bend · ★ 23.7K

A high-level, massively parallel programming language. It feels like Python or Haskell (closures, unrestricted recursion, continuations) but scales across many cores and GPUs with no thread or lock code to write.

+26

JavaGuide

Snailclimb/JavaGuide · ★ 159.1K

JavaGuide is a free, open-source guide to Java and backend interviews: a collection of study notes and Q&A summaries covering Java core, computer science fundamentals, databases, and system design.

+21

awesome-low-level-design

ashishps1/awesome-low-level-design · ★ 27.4K

A curated collection of free resources for learning Low Level Design (LLD) / Object-Oriented Design and preparing for LLD interview rounds.

+20

yazi

sxyazi/yazi · ★ 42.9K

Yazi (means 'duck') is a blazing fast terminal file manager written in Rust, built on non-blocking async I/O for an efficient, user-friendly and customizable file management experience.

The all-time top

93 projects · by stars

  1. #1 · Snailclimb/JavaGuide

    JavaGuide

    JavaGuide is a free, open-source guide to Java and backend interviews: a collection of study notes and Q&A summaries covering Java core, computer science fundamentals, databases, and system design.

    159.1K
  2. #2 · doocs/advanced-java

    advanced-java

    A free, community-curated collection of in-depth Java backend interview questions and answers, covering message queues, search engines, caching, sharding, distributed systems, high availability, microservices, and big-data processing.

    79.2K
  3. #3 · google/guava

    guava

    Guava is a set of core Java libraries from Google, providing new collection types (multimap, multiset), immutable collections, a graph library, and utilities for concurrency, I/O, hashing, primitives, and strings. It is heavily used inside Google and by many other companies.

    51.9K
  1. 4

    RxJava

    48.2KReactiveX/RxJava · Java

    RxJava is a Java library (Reactive Extensions for the JVM) for composing asynchronous and event-based programs using observable sequences.

  2. 5

    CPlusPlusThings

    43.5KLight-City/CPlusPlusThings · C++

    A Chinese-language repository (also partly in English) that walks C++ learners from basics to advanced topics: core language features, C++11/14/17/20, STL internals, design patterns, and concurrency, all backed by runnable code examples.

  3. 6

    yazi

    42.9Ksxyazi/yazi · Rust

    Yazi (means 'duck') is a blazing fast terminal file manager written in Rust, built on non-blocking async I/O for an efficient, user-friendly and customizable file management experience.

  4. 7

    interview_internal_reference

    37.3K0voice/interview_internal_reference · Python

    A curated collection of real technical interview questions and answers from major Chinese tech companies — Alibaba, Tencent, Baidu, Meituan, ByteDance and more — with analysis from expert interviewers.

  5. 8

    netty

    35.1Knetty/netty · Java

    Netty is an asynchronous, event-driven network application framework for Java, used to rapidly build maintainable, high-performance protocol servers and clients.

  6. 9

    tokio

    33.4Ktokio-rs/tokio · Rust

    Tokio is a runtime for writing reliable, asynchronous applications with Rust: it supplies the scheduling, non-blocking I/O, networking and timers that async Rust programs need.

  7. 10

    comprehensive-rust

    33.4Kgoogle/comprehensive-rust · Rust

    Comprehensive Rust is a multi-day Rust course developed by the Android team at Google, covering Rust from basic syntax to generics and error handling.

  8. 11

    yew

    32.8Kyewstack/yew · Rust

    Yew is a modern Rust framework for creating multi-threaded, front-end web apps with WebAssembly. You build the UI in Rust, and the app compiles to Wasm that runs in the browser.

  9. 12

    folly

    30.6Kfacebook/folly · C++

    Folly (Facebook Open Source Library) is a library of C++20 components built for practicality and efficiency, used extensively at Facebook and often a dependency of its other open-source C++ projects.

  10. 13

    celery

    29Kcelery/celery · Python

    Celery is a distributed task queue for Python: clients put units of work (tasks) on a queue and dedicated worker processes monitor the queue and run them — across threads, machines, even datacenters.

  11. 14

    go-patterns

    28.3Ktmrts/go-patterns · Go

    This is a curated collection of idiomatic design and application patterns for the Go (Golang) language, covering classic creational/structural/behavioral patterns plus Go-specific categories like synchronization, concurrency, messaging, stability and anti-patterns.

  12. 15

    locust

    28.2Klocustio/locust · Python

    Locust is an open source performance/load testing tool for HTTP and other protocols — you define your tests in regular Python code and run them from the command line or a web-based UI.

  13. 16

    awesome-low-level-design

    27.4Kashishps1/awesome-low-level-design · Java

    A curated collection of free resources for learning Low Level Design (LLD) / Object-Oriented Design and preparing for LLD interview rounds.

  14. 17

    libuv

    27.3Klibuv/libuv · C

    libuv is a multi-platform C support library focused on asynchronous I/O. It was originally built for Node.js and is also used by Luvit, Julia and uvloop.

  15. 18

    JCSprout

    26.8KcrossoverJie/JCSprout · Java

    JCSprout ('Java Core Sprout') is a Chinese-language knowledge base of core Java topics: a curated collection of articles on collections, multithreading, JVM internals, distributed systems, frameworks, algorithms and Netty, with over 26k GitHub stars.

  16. 19

    elixir

    26.7Kelixir-lang/elixir · Elixir

    Elixir is a programming language designed for building scalable and maintainable applications, running on the Erlang VM (BEAM).

  17. 20

    miaosha

    26.6Kqiurunze123/miaosha · Java

    This is a Chinese learning repository about designing and building a high-concurrency 'flash sale' (seckill) system for internet engineers, combining iterative demo projects, small frameworks, study notes and diagrams covering distributed-systems topics.

  18. 21

    colly

    25.6Kgocolly/colly · Go

    Colly is a scraping and crawling framework for Go: a clean interface for writing any kind of crawler, scraper or spider that extracts structured data from websites, for things like data mining, processing or archiving.

  19. 22

    toBeTopJavaer

    25.3Khollischuang/toBeTopJavaer · Java

    To Be Top Javaer (Java工程师成神之路, the Java engineer's path to mastery) is a Chinese-language knowledge base with over 25,000 GitHub stars: it maps out everything a Java developer should learn on the way from beginner to expert, and it doubles as interview preparation.

  20. 23

    redisson

    24.4Kredisson/redisson · Java

    A Java client and real-time data platform for Redis and Valkey: 50+ distributed Java objects, collections and services — maps, queues, locks, rate limiters, bloom filters, schedulers — beyond what Redis offers natively.

  21. 24

    bend

    23.7Kbendlang/bend · TypeScript

    A high-level, massively parallel programming language. It feels like Python or Haskell (closures, unrestricted recursion, continuations) but scales across many cores and GPUs with no thread or lock code to write.

  22. 25

    fasthttp

    23.5Kvalyala/fasthttp · Go

    FastHTTP is a fast HTTP server and client library for Go, tuned for high performance: zero memory allocations in hot paths and up to 10x the speed of net/http.

  23. 26

    source-code-hunter

    23.1Kdoocs/source-code-hunter · Java

    This is a curated collection of deep-dive articles that explain, from the source code itself, how popular Java frameworks and middleware actually work under the hood - including the Spring family, MyBatis, Netty, Dubbo, Redis, Tomcat, Nacos, Sentinel and RocketMQ, plus a bonus section on core JDK classes and concurrency utilities.

  24. 27

    learn_python3_spider

    22.2Kwistbean/learn_python3_spider · Python

    A free Chinese-language tutorial series that teaches Python web scraping from zero — 30+ numbered lessons and mitmproxy guides, from first packet capture to distributed crawling, with source code for the practice projects.

  25. 28

    lo

    21.4Ksamber/lo · Go

    samber/lo is a Lodash-style utility library for Go built on 1.18+ generics: dozens of helpers for filtering, mapping, grouping and reducing slices, maps, strings, channels and functions.

  26. 29

    HikariCP

    21.2Kbrettwooldridge/HikariCP · Java

    A high-performance JDBC connection pool for Java: it keeps a ready pool of database connections your app can reuse instead of opening a new one for every request. It is billed as zero-overhead and production ready.

  27. 30

    ava

    20.8Kavajs/ava · JavaScript

    AVA is a test runner for Node.js: it runs your tests with a concise API, detailed error output and thread isolation, so you can develop with confidence.

  28. 31

    TinyWebServer

    19.7Kqinguoyi/TinyWebServer · C++

    TinyWebServer is a lightweight C++ web server for Linux, built to help beginners learn and practice network programming by building their own server from scratch.

  29. 32

    athena

    18.9KZhongFuCheng3y/athena

    Athena is a Chinese-language Java backend 'knowledge graph' (知识图谱) — a huge curated collection of articles, interview-prep columns, and e-books meant to help Java beginners learn core backend topics like concurrency, the JVM, Spring, Redis, Kafka, and MySQL.

  30. 33

    swoole-src

    18.9Kswoole/swoole-src · C++

    Swoole is an event-driven, asynchronous, coroutine-based concurrency library for PHP, built for high performance.

  31. 34

    disruptor

    18.5KLMAX-Exchange/disruptor · Java

    LMAX Disruptor is a Java library for high-performance messaging between threads inside a single application — very fast in-process event passing.

  32. 35

    caffeine

    17.9Kben-manes/caffeine · Java

    Caffeine is a high-performance, near-optimal in-memory caching library for Java with a Guava-inspired API.

  33. 36

    toBeBetterJavaer

    17.8Kitwanger/toBeBetterJavaer · Java

    toBeBetterJavaer (二哥的Java进阶之路) is a free, community-built Chinese knowledge base of original articles covering Java fundamentals, concurrency, the JVM, enterprise development (Spring Boot, MySQL, Redis) and interview prep, meant to help readers 'become a better Java developer'.

  34. 37

    mars

    17.7KTencent/mars · C++

    Mars is a cross-platform network component library built by WeChat's mobile team — the same infrastructure proven by billions of WeChat users. It bundles mobile-optimized networking, logging and network diagnostics for embedding in your own app.

  35. 38

    brpc

    17.6Kapache/brpc · C++

    bRPC is an industrial-grade C++ RPC framework built at Baidu for high-performance systems like search, storage, machine learning, advertisement and recommendation; the name stands for 'better RPC'.

  36. 39

    effect

    17.3KEffect-TS/effect · TypeScript

    Effect is a TypeScript library for building robust, maintainable, type-safe, production-grade applications. It tackles the hard problems at scale: typed errors, dependency injection, structured concurrency, scheduling, tracing, and schema validation.

  37. 40

    Back-End-Developer-Interview-Questions

    17Karialdomartini/Back-End-Developer-Interview-Questions

    A curated list of back-end related interview questions covering design patterns, languages, databases, concurrency, distributed systems, security and more, meant to inspire interview conversations.

  38. 41

    Android-Universal-Image-Loader

    16.8Knostra13/Android-Universal-Image-Loader · Java

    Universal Image Loader (UIL) is a Java library for Android that loads, caches and displays images. It offers lots of configuration options and fine control over the loading and caching process.

  39. 42

    aiohttp

    16.6Kaio-libs/aiohttp · Python

    aiohttp is an asynchronous HTTP client and server framework built on asyncio: one Python package for making HTTP requests and for building web applications, with WebSockets supported out of the box.

  40. 43

    node-lessons

    16.4Kalsotang/node-lessons · JavaScript

    A free, hands-on Node.js course (titled 'Node.js 包教不包会' — roughly 'Node.js: Taught, Not Guaranteed') by alsotang, built as a series of practical lessons rather than a textbook.

  41. 44

    muduo

    16.3Kchenshuo/muduo · C++

    Muduo is a multithreaded C++ network library based on the reactor pattern, built for writing high-performance, event-driven servers on Linux.

  42. 45

    bull

    16.3KOptimalBits/bull · JavaScript

    Bull is a Redis-based queue package for Node.js for handling distributed jobs and messages — background tasks, scheduled work and message passing, written for rock solid stability and atomicity.

  43. 46

    q

    15Kkriskowal/q · JavaScript

    Q is a promise library for JavaScript: a promise is an object standing in for a function's eventual return value or thrown exception, so async code can be written without nested callback pyramids.

  44. 47

    RustTraining

    14.9Kmicrosoft/RustTraining · Rust

    Seven free Rust training books from Microsoft that take you from another programming language up to async, advanced patterns, and engineering practices.

  45. 48

    rust-by-practice

    14.8Korigin-brain/rust-by-practice · Rust

    A free online book of Rust exercises, examples, and practices designed to make you comfortable with Rust by writing and running real code instead of just reading theory.

  46. 49

    automerge-classic

    14.7Kautomerge/automerge-classic · JavaScript

    Automerge is a JavaScript library implementing a CRDT (Conflict-free Replicated Data Type) — a JSON-like document that multiple users can edit concurrently on their own copies, with all changes merging back together automatically without conflicts.

  47. 50

    vert.x

    14.7Keclipse-vertx/vert.x · Java

    Vert.x Core is a toolkit for building reactive, event-driven applications on the JVM, providing low-level support for HTTP, TCP, file system access, and more.

  48. 51

    ants

    14.5Kpanjf2000/ants · Go

    ants is a goroutine pool library for Go: it manages and recycles a massive number of goroutines with a fixed capacity, letting you limit how many run concurrently in your program.

  49. 52

    workflow

    14.4Ksogou/workflow · C++

    Sogou C++ Workflow is an enterprise-grade C++ engine for asynchronous networking and parallel computing, used internally by Sogou to power search, cloud input method, and ad services, handling billions of requests daily.

  50. 53

    PromiseKit

    14.2Kmxcl/PromiseKit · Swift

    PromiseKit is a complete promises implementation for Swift and Objective-C that simplifies asynchronous programming, so your async code ends up clearer, more readable and easier to master.

  51. 54

    skynet

    14.2Kcloudwu/skynet · C

    Skynet is a lightweight, multi-user Lua framework built on the actor model, mainly used to build online game servers.

  52. 55

    dask

    13.9Kdask/dask · Python

    Dask is a flexible parallel computing library for analytics — it runs Python data workloads as scheduled tasks so they can use many cores or machines instead of a single process.

  53. 56

    kotlinx.coroutines

    13.8KKotlin/kotlinx.coroutines · Kotlin

    kotlinx.coroutines is Kotlin's official library for writing asynchronous, non-blocking code using coroutines, with multiplatform support for JVM, JS, Native and Wasm.

  54. 57

    sidekiq

    13.6Ksidekiq/sidekiq · Ruby

    Sidekiq is a background job system for Ruby: it runs slow work like emails or uploads out-of-band, using threads to handle many jobs at the same time in the same process.

  55. 58

    mimalloc

    13.5Kmicrosoft/mimalloc · C

    mimalloc (pronounced 'me-malloc') is a compact general purpose memory allocator with excellent performance, first built by Daan Leijen for the runtime systems of the Koka and Lean languages.

  56. 59

    rayon

    13.4Krayon-rs/rayon · Rust

    Rayon is a data-parallelism library for Rust. It is extremely lightweight and makes it easy to turn a sequential computation into a parallel one, with data-race freedom guaranteed.

  57. 60

    AsyncDisplayKit

    13.3Kfacebookarchive/AsyncDisplayKit · Objective-C++

    AsyncDisplayKit (ASDK) is an iOS framework for smooth asynchronous user interfaces: it moves expensive UI work — image decoding, text sizing and rendering, layout — off the main thread so the app keeps responding to the user.

  58. 61

    akka-core

    13.3Kakka/akka-core · Scala

    Akka is a platform for building highly responsive, resilient and scalable distributed services; this repo holds its core libraries. It is used for transactional, analytical, agentic-AI, digital-twin, IoT and edge-to-cloud systems.

  59. 62

    concurrentqueue

    12.5Kcameron314/concurrentqueue · C++

    moodycamel::ConcurrentQueue is an industrial-strength, lock-free multi-producer multi-consumer queue for C++11.

  60. 63

    bloc

    12.5Kfelangel/bloc · Dart

    A predictable state management library for Dart that implements the BLoC design pattern — it separates presentation from business logic in Flutter and AngularDart apps.

  61. 64

    otp

    12.4Kerlang/otp · Erlang

    Erlang is a programming language and runtime system for building massively scalable soft real-time systems that must stay highly available. This repo ships both the language and OTP.

  62. 65

    taskflow

    12.2Ktaskflow/taskflow · C++

    Taskflow is a C++ library that helps you write high-performance task-parallel programs with high programming productivity, letting you build and run graphs of dependent tasks across CPU threads and GPUs.

  63. 66

    garnet

    12.1Kmicrosoft/garnet · C#

    Garnet is a remote cache-store from Microsoft Research: a key-value server that existing Redis clients can talk to, built for high throughput, low latency, persistence, and cluster sharding.

  64. 67

    libevent

    12Klibevent/libevent · C

    Libevent is a C library that provides an asynchronous event notification API, so programs can react to file descriptor readiness, timers, and signals without writing their own platform-specific event loop.

  65. 68

    uvloop

    11.9KMagicStack/uvloop · Cython

    uvloop is a fast, drop-in replacement for Python's built-in asyncio event loop, built on top of the libuv library.

  66. 69

    co

    11.8Ktj/co · JavaScript

    co is a small JavaScript library for Node.js that gives you generator-based control flow: you write async, non-blocking code that reads like normal sequential code, with promises underneath.

  67. 70

    JoltPhysics

    11.7Kjrouwe/JoltPhysics · C++

    Jolt Physics is a multi-core friendly rigid body physics and collision detection library written in C++, built for games and VR applications. It's the engine behind 'Horizon Forbidden West' and 'Death Stranding 2: On the Beach'.

  68. 71

    FileDownloader

    11.1Klingochamp/FileDownloader · Java

    FileDownloader is an Android library for building multi-task file downloads, with breakpoint-resume, multi-thread (multi-connection) downloading per task, and high concurrency support.

  69. 72

    libzmq

    11Kzeromq/libzmq · C++

    libzmq is the core engine of ZeroMQ — a lightweight messaging kernel written in C++ that implements the ZMTP/3.1 protocol.

  70. 73

    orleans

    10.9Kdotnet/orleans · C#

    Orleans is a cross-platform .NET framework for building robust, scalable distributed applications — from a single on-premises server up to globally distributed, highly available cloud services. It's often referred to as 'Distributed .NET'.

  71. 74

    gqlgen

    10.8K99designs/gqlgen · Go

    gqlgen is a Go library for building GraphQL servers without a lot of boilerplate, using a schema-first, code-generation approach.

  72. 75

    libgit2

    10.6Klibgit2/libgit2 · C

    libgit2 is a portable, pure C implementation of the Git core methods, shipped as a linkable library with a solid API so applications can build Git functionality right in.

  73. 76

    gocui

    10.6Kjroimartin/gocui · Go

    Gocui is a minimalist Go package for building Console User Interfaces — text-mode apps that run in the terminal, with windows, keybindings and mouse support.

  74. 77

    conc

    10.4Ksourcegraph/conc · Go

    conc is a Go library — a 'toolbelt' for structured concurrency that makes common concurrent patterns in Go easier and safer than raw goroutines and sync primitives.

  75. 78

    pgrust

    5.3Kmalisper/pgrust · Rust

    pgrust is a from-scratch reimplementation of PostgreSQL in Rust, built to be wire- and SQL-dialect compatible with Postgres while being faster than both Postgres and ClickHouse.

  76. 79

    perry

    5KPerryTS/perry · Rust

    Perry compiles the TypeScript or JavaScript you already write directly into native machine-code executables for macOS, Windows, Linux, iOS, Android, watchOS and TV, using SWC to parse and LLVM to generate code, so there is no Node.js runtime or Electron bundle to ship.

  77. 80

    zenc

    4.3Kzenc-lang/zenc · C

    Zen C is a modern systems programming language with high-level ergonomics (type inference, pattern matching, generics, traits, async/await) that compiles to human-readable GNU C/C11 while maintaining 100% C ABI compatibility.

  78. 81

    coost

    4.2Kidealvin/coost · C++

    coost (aka co) is a lightweight, high-performance, easy-to-use C++ base library whose stated goal is to make C++ programming simple and enjoyable.

  79. 82

    Skills

    4KDimillian/Skills · Shell

    This is a collection of 16 reusable Codex Skills for Apple-platform engineering: SwiftUI/Xcode code review, refactoring, debugging, performance audits, GitHub workflow automation, and multi-agent review and bug-hunt swarms.

  80. 83

    unreal-agent

    2.2Kunreallabsai/unreal-agent · Go

    Unreal Agent is an async-first agent harness written in Go — a toolkit for running LLM agents with persistent, forkable sessions, tool calling, and durable background work.

  81. 84

    compio

    1.9Kcompio-rs/compio · Rust

    Compio is a thread-per-core async Rust runtime that uses completion-based IO backends (IOCP on Windows, io_uring on Linux, polling elsewhere) instead of the poll-based model most runtimes use.

  82. 85

    hotpath-rs

    1.9Kpawurb/hotpath-rs · Rust

    hotpath-rs is a Rust performance profiler that shows exactly where your code spends time, burns CPU, and allocates memory, covering async execution, SQL/HTTP calls, I/O streams, and lock contention.

  83. 86

    cpu-performance-engineering

    1.2Kusamahz/cpu-performance-engineering · Python

    A curated reading path for CPU performance engineering: it walks you from what one instruction does on a modern core to serving ML inference on CPUs, ordered so each piece makes the next one legible.

  84. 87

    goose

    607aardappel/goose · C++

    Goose is a memory-safe systems programming language with no heap allocator, garbage collector, or lifetime annotations. In its own benchmarks it runs faster than C++ and safe Rust while using less memory.

  85. 88

    Kof4j

    286KofLang/Kof4j · Java

    Kof (pronounced 'coffe') is a general-purpose, statically typed programming language with its own compiler. One language compiles to JVM, native binaries, JavaScript and Android — only the target changes, not the language.

  86. 89

    moejs

    285Calcium-Ion/moejs · Go

    moejs is a JavaScript engine written entirely in Go, meant to run small JavaScript plugins safely and fast inside a Go host program.

  87. 90

    captcha-api

    258jamespolyakov9829/captcha-api · Python

    A dependency-free Python client and CLI for the Clearance captcha-solving API, giving one interface to solve both the Cloudflare Challenge ('Just a moment.' interstitial) and the Turnstile widget.

  88. 91

    imp

    254deepfates/imp · Elixir

    Imp is a full port of DSPy to the BEAM: an Elixir framework for building and automatically improving language-model programs. You declare a step's inputs and outputs as a typed signature, and an optimizer tunes its prompts or examples against labeled data.

  89. 92

    spec-ptc

    223alexzhang13/spec-ptc · Python

    sPTC (speculative programmatic tool-calling) is a technique and small library that speculates and queues tool calls hidden inside a partially-generated REPL code block, so harnesses like RLM or CodeAct can start expensive sub-LLM/tool calls before the model even finishes writing the code.

  90. 93

    toolrush

    157OnlyTerp/toolrush · Python

    ToolRush is a low-overhead execution layer plugin for Hermes Agent (Nous Research's agent harness) that eliminates the latency overhead of tool calls like file reads, searches, and terminal commands while keeping the same tools, outputs, and safety gates.

Often tagged together