Node.js Certification Study Guide
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Preface

1. 000Certification overview & environment

Node.js Application Developer Certification (JSNAD)

1. Content/Skills coveredWeight
2. 001Buffers & Streams11%
3. 002Control flow12%
4. 003Child processes8%
5. 004Debugging Node.js6%
6. 005Error handling8%
7. 006Node.js CLI4%
8. 007Events11%
9. 008File system8%
10. 009JavaScript prerequisites7%
11. 010Module system7%
12. 011Process/Operating system6%
13. 012Package.json6%
14. 013Unit testing6%

Node.js Services Developer Certification (JSNSD)

1. Content/Skills coveredWeight
2. 001Servers and Services70%
3. 002Security30%

000Certification overview

There are 2 certification exams. If you’re only going to take one, we recommend focusing on the JSNAD exam first.

OpenJS Node Application Developer (JSNAD)

• Demonstrate competence developing Node.js applications of any kind
• Focus on Node.js core APIs and common types of applications Node.js is used to build
• Format: ~ 25 questions, 5-10 minutes each
• Exam content is outlined in more detail than the JSNSD

OpenJS Node Services Developer (JSNSD)

• Demonstrate competence developing RESTful Node.js servers and services with an emphasis on security.
• Format: ~ 4-5 questions, 15-30 minutes each

What to expect:

• Target audience: Upper intermediate level Node.js developers
• Both exams currently target Node.js version 10.16 LTS. We suggest learning the latest version and then checking for discrepancies between that version and the 10.16 LTS.
• Exam content will change as Node evolves, and will be different for each taker.
• The two-hour exam sessions will be closely monitored by a proctor via webcam, audio, and remote screen viewing.
• Use any ecosystem libraries, and most online resources except Stack Exchange, Stack Overflow, or related sites encouraging copy/paste solutions.
• Exam focus: practical outcomes and problem solving. You’re scored based on whether you successfully solve the problem, not the specifics of how you solved it.
• Use core Node APIs, or any library of your choice.
• One free exam retake, and rolling promotions on the exam cost.
• For more info, see the exam tips and important instructions from the OpenJS Foundation.

The exam environment

Both exams are administered online and require using a Remote Desktop Linux environment. You’ll be required to write code using either Visual Studio Code or Vim. You’ll also be able to use Postman, Chrome, and the terminal. In some cases, partial code may be provided to save time. In other contexts, you’ll write an entire program.

001Buffers & Streams

Key competencies include; Node.js Buffer API’s, incremental processing, transforming data, and connecting streams.

1. What Is a Stream?heynode.com
2. Node.js Streams: Everything you need to knowfreecodecamp.org
3. bookNode Cookbook, 3rd Edition - Chapter 4 - Using Streamspacktpub.com
4. stream-handbookgithub.com
5. nodeschoolstream-adventuregithub.com
6. api docsStream documentationnodejs.org
7. api docsBuffer documentationnodejs.org

002Control flow

Key competencies include; Managing asynchronous operations and control flow abstractions.

1. What Are Promises?heynode.com
2. Use Async/Await with Promisesheynode.com
3. 7. Control Flowbook.mixu.net
4. nodeschoollearnyounodegithub.com
5. nodeschoolasync-yougithub.com
6. nodeschoolpromise-it-wont-hurtgithub.com

003Child processes

Key competencies include; Spawning or executing child processes, and child process configuration.

1. Node.js Child Processes: Everything you need to knowfreecodecamp.org
2. How to spawn a child process with Node.jsflaviocopes.com
3. api docsChild_process documentationnodejs.org

004Debugging Node.js

Key competencies include; Debugging Node.js, basic performance analysis.

1. bookNode Cookbook, 3rd Edition - Chapter 1 - Debugging Processespacktpub.com
2. bookNode Cookbook, 3rd Edition - Chapter 9 - Optimizing Performancepacktpub.com
3. Node.js debugging in VS Codecode.visualstudio.com
4. videoGetting started with Node.js debugging in VS Codeyoutube.com
5. Debugging Guidenodejs.org
6. Easy profiling for Node.js Applicationsnodejs.org
7. api docsconsole documentationnodejs.org
8. api docsdebugger documentationnodejs.org
9. npmjs.com/package/0xnpmjs.com
10. nodeschoolbug-clinicgithub.com

005Error handling

Key competencies include; Common error handling patterns, handling errors in various scenarios.

1. Better Error Handling In NodeJS With Error Classessmashingmagazine.com
2. Handling Errors in JavaScript: The Definitive Guidelevelup.gitconnected.com
3. Unhandled Promise Rejections in Node.jsthecodebarbarian.com
4. How to prevent your Node.js process from crashingmedium.com
5. api docsError documentationnodejs.org
6. testingjavascript.comKent C. Dodds, subscription required

006Node.js CLI

Key competencies include; Understand and use node executable command line flags.

1. Run `man node` in your CLI to get a complete list of available options.
2. Mastering the Node.js CLI & Command Line Optionsblog.risingstack.com
3. api docsNode.js CLI documentationnodejs.org

007Events

Key competencies include; Understand the event system, build event emitters, consume event emitters.

1. How to code your own event emitter in Node.js: a step-by-step guidefreecodecamp.org
2. Handling and dispatching events with Node.jsblog.logrocket.com
3. api docsEvents documentationnodejs.org

008File system

Key competencies include; Input/output and watching files and directories.

1. What Is the fs File System Module?heynode.com
2. Read/Write JSON Files with Node.jsheynode.com
3. bookNode Cookbook, 3rd Edition - Chapter 3 - Coordinating IOpacktpub.com
4. api docsfs documentationnodejs.org
5. nodeschoollearnyounodegithub.com

009JavaScript prerequisites

Key competencies include; Language fundamentals, scoped to core language features introduced since EcmaScript 1 and still heavily used today.

1. Most Recommended JavaScript Learning Resourcesjavascriptstuff.com
2. eloquentjavascript.neteloquentjavascript.net
3. bookYou Don't Know JSgithub.com
4. nodeschoolscopes-chains-closuresgithub.com

010Module system

Key competencies include; CommonJS Module System only (ES modules not introduced to Node core until after 10.x).

1. Overview: Node's Module Systemheynode.com
2. Requiring modules in Node.js: Everything you need to knowfreecodecamp.org
3. bookNode Cookbook, 3rd Edition - Chapter 2- Writing Modulespacktpub.com
4. api docsmodule documentationnodejs.org
5. nodeschoollearnyounodegithub.com

011Process/Operating system

Key competencies include; Controlling the process, and getting system data.

1. Mastering the Node.js Core Modules - The Process Moduleblog.risingstack.com
2. bookNode Cookbook, 3rd Edition - Chapter 3 - Coordinating IOpacktpub.com
3. api docsos documentationnodejs.org
4. api docsprocess documentationnodejs.org

012Package.json

Key competencies include; Package configuration, and dependency management.

1. What Is package.json?heynode.com
2. Create a package.json Fileheynode.com
3. Install NPM Packagesheynode.com
4. What Is Semantic Versioning (SemVer)?heynode.com
5. What Are NPM Scripts?heynode.com
6. bookNode Cookbook, 3rd Edition - Chapter 2- Writing Modulespacktpub.com
7. nodeschoolhow-to-npmgithub.com

013Unit testing

Key competencies include; Using assertions, testing synchronous code, and testing asynchronous code. The exam doesn't prescribe a specific framework; We recommend you pick one and learn it.

1. Mochagithub.com
2. Jestgithub.com
3. Testing JavaScript with Jestflaviocopes.com
4. api docsassert documentationnodejs.org
5. testingjavascript.comKent C. Dodds, subscription required

001Servers and Services

Key competencies include; Implementing public facing web servers, creating RESTful services, consuming HTTP services, knowledge of HTTP verbs and status codes, and processing user input. Resources coming soon ...

002Security

Key competencies include; Protecting against malicious input, and attack mitigation. Resources coming soon ...