Editing Technical Test

==Technical Test==

===overview===
# code
# system design
# leadership
===html/css===
====Box Model====
The CSS box model is essentially a box that wraps around every HTML element. It consists of: margins, borders, padding, and the actual content.
==== Semantic HTML5 ====
The following HTML tags can be used to break your page into identified parts:

* <header>: Defines a header for a web page.
* <nav>: Defines a container for navigation links.
* <section>: Defines a section in a web page.
* <article>: This element contains the main part, containing information about the web page.
* <aside>: The <aside> content is often placed as a sidebar in a document.
* <footer>: It defines a footer for a document or a section.

===JavaScript===
====What is a dependency injection?====
DI is a pattern where, instead of creating or requiring dependencies directly inside a module, we pass them as parameters or reference.
====Arrow Functions====
ES6 syntactic sugar, for more concise functions.
* Arrow functions do not have an arguments binding.
* arrow functions do not have their own 'this' keyword.
* Cannot be used for constructors ('new' keyword).

===architecture/design===
====network====
short poll / long poll / web sockets
* Short polling (a.k.a. AJAX based timer):
** Pros: simpler, not server consuming (if the time between requests is long).
** Cons: bad if you need to be notified WHEN the server event happens with no delay.
* Long polling (a.k.a. Comet based on XHR)
** is Half-Duplex meaning that a new request-response cycle is required each time the client wants to communicate something to the server.
** Pros: you are notified WHEN the server event happens with no delay. 
** Cons: more complex and more server resources used. 
* Web Socket
** Full-Duplex meaning both the client and the server can send and receive messages across the channel.

====performance====
* FrontEnd
** Critical Render Path
** Optimize code
** Progressive Web App
** Code Splitting / Progressive Bootstrap / Lazy Load (http2 have small chunks)


* Delivery
** minimize files
** minimize delivery

* Backend
** CDNs
** Caching
** Load balancing
** DB Scaling
** GZip

====MEAN Stack====
MEAN (MongoDB, Express.js, AngularJS (or Angular), and Node.js)
====What is CRUD?====
Create, Read, Update, and Delete (CRUD) for an API

====REST vs GraphQL====
=====GraphQL Advantages=====
No more Over- and Underfetching. In GraphQL, you specify exactly what you need. REST, requires multiple requests and API reflects UI. When UI changes, over/under fetching the API occurs.
* GraphQL can decouple frontend from backend.
* API evolution is possible without versioning.
* It is statically typed, so you do not need to define variable before using it.
* No over or under fetching of data.
* It is language and HTTP agnostic.
* Documentation of GraqphQL comes with no extra cost.
* It helps you to save bandwidth.
=====GraphQL Disadvantages=====
* GraphQL uses a single endpoint instead of following the HTTP caching.
* Adds complexity / overkill for small applications

=====REST Advantages=====
industry standard for companies deploying APIs
* Services of REST can be scaled to achieve high performance to span client demand.
* The API of REST can be served from more than one server.
* REST allows you to store frequently used information in the memory.
* REST has a uniform interface.
* Resources can be easily accessed by name.
* Database resource in an application can be quickly mapped with a REST API endpoint.
* It has a simple architecture and pattern.
=====REST Disadvantages=====
* If you have to retrieve any data from two endpoints, you need to send two separate requests to API.
* There is no way to get limited fields.

===general programming===
====What is CI/CD?====
CICD is the combined practices of continuous integration and continuous delivery or continuous deployment. CI/CD bridges the gaps between development and operation activities and teams by enforcing automation in building, testing and deployment of applications.

====TDD/Unit Tests/FIRST====
FIRST properties of Unit Tests. http://agileinaflash.blogspot.com/2009/02/red-green-refactor.html
* Fast: unit test must be fast - A software project will eventually have tens of thousands of unit tests, and team members need to run them all every minute or so without guilt. 
* Isolated: Tests isolate failures. A good unit test has a laser-tight focus on a single effect or decision. Good tests interferes with no other tests in any way. They impose their initial state without aid from other tests. They clean up after themselves.
* Repeatable:  Tests must be able to be run repeatedly without intervention.
* Self-validating: Tests are pass-fail.
* Timely: Tests are written at the right time, immediately before the code that makes the tests pass.

====TDD: Red/Green/Refactor====
http://agileinaflash.blogspot.com/2009/02/red-green-refactor.html
* Red: Failed test
* Green: Passed test
* Refactor: Clean up. Remove code. make into smaller units. performance.
====Types of Tests====
* Unit Tests - small. quick. Jest/NUnit/PHPUnit
* Integration Tests - connect components to see how they work together. Slower to write/run.
* Automation Tests - UI test/end-to-end tests. simulate user behavior.  Nightmare (https://github.com/segmentio/nightmare).

====AUTH====
=====JWT=====
=====OAuth=====