This is a guide that everyone can use to learn about the practice of front-end development. It broadly outlines and discusses the practice of front-end engineering: how to learn it and what tools are used when practicing it in 2019.
It is specifically written with the intention of being a professional resource for potential and currently practicing front-end developers to equip themselves with learning materials and development tools. Secondarily, it can be used by managers, CTOs, instructors, and head hunters to gain insights into the practice of front-end development.
The content of the handbook favors web technologies (HTML, CSS, DOM, and JavaScript) and those solutions that are directly built on top of these open technologies. The materials referenced and discussed in the book are either best in class or the current offering to a problem.
The book should not be considered a comprehensive outline of all resources available to a front-end developer. The value of the book is tied up in a terse, focused, and timely curation of just enough categorical information so as not to overwhelm anyone on any one particular subject matter.
The intention is to release an update to the content yearly. This is currently the fourth year an edition has been released.
What is in this Handbook:
Chapter 0 provides a lite recap of the year in front-end development and what may be to come. Chapter 1 & 2 aim to give a brief overview of the discipline and practice of front-end development. Chapters 3 & 4 organize and recommend learning paths and resources. Chapter 5 organizes and list the tools used by front-end developers and Chapter 6 highlights front-end information outlets.
Contribute content, suggestions, and fixes on github:
This chapter provides a baseline explanation for front-end development and the front-end developer discipline.
Front-end web development, also known as client-side development is the practice of producing HTML, CSS and JavaScript for a website or Web Application so that a user can see and interact with them directly. The challenge associated with front end development is that the tools and techniques used to create the front end of a website change constantly and so the developer needs to constantly be aware of how the field is developing.
The objective of designing a site is to ensure that when the users open up the site they see the information in a format that is easy to read and relevant. This is further complicated by the fact that users now use a large variety of devices with varying screen sizes and resolutions thus forcing the designer to take into consideration these aspects when designing the site. They need to ensure that their site comes up correctly in different browsers (cross-browser), different operating systems (cross-platform) and different devices (cross-device), which requires careful planning on the side of the developer.
https://en.wikipedia.org/wiki/Front-end_web_development
Image source: https://www.upwork.com/hiring/development/front-end-developer/
A front-end developer architects and develops websites and web applications using web technologies (i.e., HTML, CSS, and JavaScript), which typically runs on the Open Web Platform or acts as compilation input for non-web platform environments (i.e., React Native).
A person enters into the field of front-end development by learning to build a website or web application which relies on HTML, CSS, and JavaScript and commonly runs in a web browser but can also run in a headless browser, WebView, or as compilation input for a native runtime environment. These four run times scenarios are explained below.
Web Browsers (most common)
A web browser is software used to retrieve, present, and traverse information on the WWW. Typically, browsers run on a desktop or laptop computer, tablet, or phone, but as of late a browser can be found on just about anything (i.e, on a fridge, in cars, etc.).
The most common web browsers are (shown in order of most used first):
Headless Browsers
Headless browsers are a web browser without a graphical user interface that can be controlled from a command line interface programmatically for the purpose of web page automation (e.g., functional testing, scraping, unit testing, etc.). Think of headless browsers as a browser that you can run programmatically from the command line that can retrieve and traverse web page code.
The most common headless browsers are:
Webviews
Webviews are used by a native OS, in a native application, to run web pages. Think of a webview like an iframe or a single tab from a web browser that is embedded in a native application running on a device (e.g., iOS, android, windows).
The most common solutions for webview development are:
Native from Web Tech
Eventually, what is learned from web browser development can be used by front-end developers to craft code for environments that are not fueled by a browser engine (i.e. web platform). As of late, development environments are being dreamed up that use web technologies (e.g., CSS and JavaScript), without web engines, to create native applications.
Some examples of these environments are:
Notes:
This chapter will break down and broadly describes the practice of front-end engineering starting with, "How Front-End Developers Are Made".
How exactly does one become a front-end developer? Well, it's complicated. Just consider this road map:
Today, in general, one can't go to college and expect to graduate with a degree in front-end engineering. And, I rarely hear of or meet front-end developers who suffered through what is likely a deprecated computer science degree or graphic design degree to end up writing HTML, CSS, and JavaScript professionally. From my perspective, most of the people working on the front-end today generally seem to be self-taught from the ground up or cross over into the front-end space from design or computer science fields.
If you were to set out today to become a front-end developer I would loosely strive to follow the process outlined below (Chapter 3 and Chapter 4 will dive into more details on learning resources).
A short word of advice on learning. Learn the actual underlying technologies, before learning abstractions. Don't learn jQuery, learn the DOM. Don't learn SASS, learn CSS. Don't learn JSX, learn HTML. Don't learn TypeScript, learn JavaScript. Don't learn Handlebars, learn JavaScript ES6 templates. Don't just use Bootstrap, learn UI patterns.
Lately a lot of non-accredited, expensive, front-end code schools/bootcamps have emerged. These avenues of becoming a front-end developer are typically teacher directed courses, that follow a more traditional style of learning, from an official instructor (i.e., syllabus, test, quizzes, projects, team projects, grades, etc.).
Keep in mind, if you are considering an expensive training program, this is the web! Everything you need to learn is on the web for the taking, costing little to nothing. However, if you need someone to tell you how to take and learn what is low cost to free, and hold you accountable for learning it, you should consider a traditional instructor lead class room setting. Otherwise, I am not aware of any other profession that is practically free for the taking with an internet connection, a couple of dollars a month for screencasting memberships, and a burning desire for knowledge.
For example, if you want to get going today, consuming one or more of the following self-directed resources below can work:
When getting your start, you should fear most things that conceal complexity. Abstractions (e.g. jQuery) in the wrong hands can give the appearance of advanced skills, while all the time hiding the fact that a developer has an inferior understanding of the basics or underlying concepts.
It is assumed that on this journey you are not only learning, but also doing as you learn and investigate tools. Some suggest only doing to learn. While others suggest only learning about doing. I suggest you find a mix of both that matches how your brain works and do that. But, for sure, it is a mix! So, don't just read about it, do it. Learn, do. Learn, do. Repeat indefinitely because things change fast. This is why learning the fundamentals, and not abstractions, are so important.
A great divide has been brewing in the front-end developer space for several years between two very different types of so-called front-end developers. On the one side, you have JavaScript-focused programmers who write JavaScript for front-end runtimes that likely have computer science skills with a software development history. They more than likely view HTML and CSS as an abstraction (i.e. JSX and CSS in JS). On the other side, you have, most likely, non-computer science educated developers who focus on HTML, CSS, and JavaScript as it specifically pertains to the UI. In 2019, when entering or trying to understand the front-end developer space you will absolutely feel this divide. The term front-end developer is on the verge of meaninglessness without clarifying words to address what type of front-end developer is being discussed.
Below is a list and description of various front-end job titles (Keep in mind titles are hard). The common, or most used (i.e., generic), title for a front-end developer is, "front-end developer" or "front-end engineer". Note that any job that contains the word "front-end", "client-side", "web UI", "HTML", "CSS", or "JavaScript" typically infers that a person has some degree of HTML, CSS, DOM, and JavaScript professional know how.
Front-End Developer: The generic job title that describes a developer who is skilled to some degree at HTML, CSS, DOM, and JavaScript and implementing these technologies on the web platform.
Front-End Engineer (aka JavaScript Developer or Full-stack JavaScript Developer): The job title given to a developer who comes from a computer science, engineering, background and is using these skills to work with front-end technologies. This role typically requires computer science knowledge and years of software development experience. When the word "JavaScript Application" is included in the job title, this will denote that the developer should be an advanced JavaScript developer possessing advanced programming, software development, and application development skills (i.e has years of experience building front-end software applications).
CSS/HTML Developer: The front-end job title that describes a developer who is skilled at HTML and CSS, excluding JavaScript and application, know how.
Front-End Web Designer: When the word "Designer" is included in the job title, this will denote that the designer will possess front-end skills (i.e., HTML & CSS) but also professional design (Visual Design and Interaction Design) skills.
UI (User Interface) Developer/Engineer: When the word "Interface" or "UI" is included in the job title, this will denote that the developer should posses interaction design skills in addition to front-end developer skills or front-end engineering skills.
Mobile/Tablet Front-End Developer: When the word "Mobile" or "Tablet" is included in the job title, this will denote that the developer has experience developing front-ends that run on mobile or tablet devices (either natively or on the web platform, i.e., in a browser).
Front-End SEO Expert: When the word "SEO" is included in the job title, this will denote that the developer has extensive experience crafting front-end technologies towards an SEO strategy.
Front-End Accessibility Expert: When the word "Accessibility" is included in the job title, this will denote that the developer has extensive experience crafting front-end technologies that support accessibility requirements and standards.
Front-End Dev. Ops: When the word "DevOps" is included in the job title, this will denote that the developer has extensive experience with software development practices pertaining to collaboration, integration, deployment, automation, and quality.
Front-End Testing/QA: When the word "Testing" or "QA" is included in the job title, this will denote that the developer has extensive experience testing and managing software that involves unit testing, functional testing, user testing, and A/B testing.
Notes:
The following core web technologies are employed by front-end developers (consider learning them in this order):
For a comprehensive list of all web related specifications have a look at platform.html5.org or MDN Web APIs.
The nine technologies just mentioned are defined below along with a link to the relevant documentation and specification for each technology.
HyperText Markup Language, commonly referred to as HTML, is the standard markup language used to create web pages. Web browsers can read HTML files and render them into visible or audible web pages. HTML describes the structure of a website semantically along with cues for presentation, making it a markup language, rather than a programming language.
— Wikipedia
Most relevant specifications / documentation:
Cascading Style Sheets (CSS) is a style sheet language used for describing the look and formatting of a document written in a markup language. Although most often used to change the style of web pages and user interfaces written in HTML and XHTML, the language can be applied to any kind of XML document, including plain XML, SVG and XUL. Along with HTML and JavaScript, CSS is a cornerstone technology used by most websites to create visually engaging webpages, user interfaces for web applications, and user interfaces for many mobile applications.
— Wikipedia
Most relevant specifications / documentation:
The Hypertext Transfer Protocol (HTTP) is an application protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web.
— Wikipedia
Most relevant specifications:
A uniform resource locator (URL) (also called a web address) is a reference to a resource that specifies the location of the resource on a computer network and a mechanism for retrieving it. A URL is a specific type of uniform resource identifier (URI), although many people use the two terms interchangeably. A URL implies the means to access an indicated resource, which is not true of every URI. URLs occur most commonly to reference web pages (http), but are also used for file transfer (ftp), email (mailto), database access (JDBC), and many other applications.
— Wikipedia
Most relevant specifications:
The Document Object Model (DOM) is a cross-platform and language-independent convention for representing and interacting with objects in HTML, XHTML, and XML documents. The nodes of every document are organized in a tree structure, called the DOM tree. Objects in the DOM tree may be addressed and manipulated by using methods on the objects. The public interface of a DOM is specified in its application programming interface (API).
— Wikipedia
Most relevant specifications / documentation:
JavaScript is a high level, dynamic, untyped, and interpreted programming language. It has been standardized in the ECMAScript language specification. Alongside HTML and CSS, it is one of the three essential technologies of World Wide Web content production; the majority of websites employ it and it is supported by all modern web browsers without plug-ins. JavaScript is prototype-based with first-class functions, making it a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles. It has an API for working with text, arrays, dates and regular expressions, but does not include any I/O, such as networking, storage or graphics facilities, relying for these upon the host environment in which it is embedded.
— Wikipedia
Most relevant specifications / documentation:
When writing code for the Web using JavaScript, there are a great many APIs available. Below is a list of all the interfaces (that is, types of objects) that you may be able to use while developing your Web app or site.
— Mozilla
Most relevant documentation:
It is the primary data format used for asynchronous browser/server communication (AJAJ), largely replacing XML (used by AJAX). Although originally derived from the JavaScript scripting language, JSON is a language-independent data format. Code for parsing and generating JSON data is readily available in many programming languages. The JSON format was originally specified by Douglas Crockford. It is currently described by two competing standards, RFC 7159 and ECMA-404. The ECMA standard is minimal, describing only the allowed grammar syntax, whereas the RFC also provides some semantic and security considerations. The official Internet media type for JSON is application/json. The JSON filename extension is .json.
— Wikipedia
Most relevant specifications:
Accessibility refers to the design of products, devices, services, or environments for people with disabilities. The concept of accessible design ensures both “direct access” (i.e., unassisted) and "indirect access" meaning compatibility with a person's assistive technology (for example, computer screen readers).
— Wikipedia
A basic to advanced understanding of HTML, CSS, DOM, JavaScript, HTTP/URL, and web browsers is assumed for any type of professional front-end developer role.
Beyond the skills just mentioned, a front-end developer might also be specifically skilled in one or more of the following:
A front-end developer crafts HTML, CSS, and JS that typically runs on the web platform (e.g. a web browser) delivered from one of the following operating systems (aka OSs):
These operating systems typically run on one or more of the following devices:
Generally speaking, front-end technologies can run on the aforementioned operating systems and devices using the following run time web platform scenarios:
A front-end developer is typically only one player on a team that designs and develops web sites, web applications, or native applications running from web technologies.
A bare-bones development team for building professional web sites or software for the web platform will typically, minimally, contain the following roles.
The roles are ordered according to overlapping skills. A front-end developer will typically have a good handle on UI/Interaction design as well as back-end development. It is not uncommon for team members to fill more than one role by taking on the responsibilities of an over-lapping role.
It is assumed that the team mentioned above is being directed by a project lead or some kind of product owner (i.e., stakeholder, project manager, project lead, etc.)
A larger web team might include the following roles not shown above:
The term "Full-Stack" developer has come to take on several meanings. So many, that not one meaning is clear when the term is used. Just consider the results from the two surveys shown below. These results might lead one to believe that being a full-stack developer is commonplace. But, in my almost 20 years of experience, this is anything but the case in a professional context.
The roles to design and develop a website or web application require a deep set of skills and vast experience in the area of visual design, UI/interaction design, front-end development, and back-end development. Any person who can fill one or more of these 4 roles at a professional level is an extremely rare commodity.
Pragmatically, you should seek to be, or seek to hire, an expert in one of these roles (i.e. Visual Design, Interaction Design/IA, Front-end Dev, Back-end Dev). Those who claim to operate at an expert level at one or more of these roles are exceptionally rare.
However, given that JavaScript has infiltrated all layers of a technology stack (i.e. Node.js) finding a full-stack JS developer who can code the front-end and back-end is becoming less mythical. Typically, these full-stack developers only deal with JavaScript. A developer who can code the front-end, back-end, API, and database isn't as absurd as it once was (excluding visual design, interaction design, and CSS). Still mythical in my opinion, but not as uncommon as it once was. Thus, I wouldn't recommend a developer set out to become a "full-stack" developer. In rare situations, it can work. But, as a general concept for building a career as a front-end developer, I'd focus on front-end technologies.
A plethora of technical job listing outlets exist. The narrowed list below are currently the most relevant resources for finding a specific front-end position/career.
Notes:
The national average in the U.S for a mid-level front-end developer is somewhere between $65k and 100k.
Of course when you first start expect to enter the field at around 40k depending upon location and experience.
Notes:
This chapter highlights the many resources (video training, books, etc.) that an individual can use to direct their own learning process and career as a front-end developer.
The learning resources identified (articles, books, videos, screencasts etc..) will include both free and paid material. Paid material will be indicated with [$].
The Internet is a global system of interconnected computer networks that use the Internet protocol suite (TCP/IP) to link several billion devices worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries an extensive range of information resources and services, such as the inter-linked hypertext documents and applications of the World Wide Web (WWW), electronic mail, telephony, and peer-to-peer networks for file sharing.
— Wikipedia
A web browser (commonly referred to as a browser) is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI/URL) and may be a web page, image, video or other piece of content. Hyperlinks present in resources enable users easily to navigate their browsers to related resources. Although browsers are primarily intended to use the World Wide Web, they can also be used to access information provided by web servers in private networks or files in file systems.
— Wikipedia
In the past, front-end developers spent a lot of time making code work in several different browsers. This was once a bigger issue than it is today. Today, abstractions (e.g., React, Webpack, Post-CSS, Babel etc. ) combined with modern browsers make browser development fairly easy. The new challenge is not which browser the user will use, but on which device they will run the browser.
The latest versions of most modern browsers are considered evergreen browsers. That is, in theory, they are supposed to automatically update themselves silently without prompting the user. This move towards self-updating browsers has been in reaction to the slow process of eliminating older browsers that do not auto-update.
As of today, most front-end developers use Chrome and "Chrome Dev Tools" to develop front-end code. However, the most used modern browsers all offer a flavor of developer tools. Picking one to use for development is a subjective choice. The more important issue is knowing which browsers, on which devices, you have to support and then testing appropriately.
The Domain Name System (DNS) is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participating entities. Most prominently, it translates domain names, which can be easily memorized by humans, to the numerical IP addresses needed for the purpose of computer services and devices worldwide. The Domain Name System is an essential component of the functionality of most Internet services because it is the Internet's primary directory service.
— Wikipedia
HTTP - The Hypertext Transfer Protocol (HTTP) is an application protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web.
— Wikipedia
CORS - Cross-origin resource sharing (CORS) is a mechanism that allows restricted resources (e.g., fonts) on a web page to be requested from another domain outside the domain from which the resource originated.
— Wikipedia
WebSockets - WebSocket is a protocol providing full-duplex communication channels over a single TCP connection. The WebSocket protocol was standardized by the IETF as RFC 6455 in 2011, and the WebSocket API in Web IDL is being standardized by the W3C.
— Wikipedia
A web hosting service is a type of Internet hosting service that allows individuals and organizations to make their website accessible via the World Wide Web. Web hosts are companies that provide space on a server owned or leased for use by clients, as well as providing Internet connectivity, typically in a data center.
— Wikipedia
User Interface Design - User interface design (UI) or user interface engineering is the design of user interfaces for machines and software, such as computers, home appliances, mobile devices, and other electronic devices, with the focus on maximizing the user experience. The goal of user interface design is to make the user's interaction as simple and efficient as possible, in terms of accomplishing user goals (user-centered design).
— Wikipedia
Interaction Design Pattern - A design pattern is a formal way of documenting a solution to a common design problem. The idea was introduced by the architect Christopher Alexander for use in urban planning and building architecture, and has been adapted for various other disciplines, including teaching and pedagogy, development organization and process, and software architecture and design.
— Wikipedia
User Experience Design - User Experience Design (UXD or UED or XD) is the process of enhancing user satisfaction by improving the usability, accessibility, and pleasure provided in the interaction between the user and the product. User experience design encompasses traditional human–computer interaction (HCI) design, and extends it by addressing all aspects of a product or service as perceived by users.
— Wikipedia
Human–Computer Interaction - Human–computer interaction (HCI) researches the design and use of computer technology, focusing particularly on the interfaces between people (users) and computers. Researchers in the field of HCI both observe the ways in which humans interact with computers and design technologies that lets humans interact with computers in novel ways.
— Wikipedia
Minimally I'd suggest reading the following canonical texts on the matter so one can support and potential build usable user interfaces.
HTML - HyperText Markup Language, commonly referred to as HTML, is the standard markup language used to create web pages. Web browsers can read HTML files and render them into visible or audible web pages. HTML describes the structure of a website semantically along with cues for presentation, making it a markup language, rather than a programming language.
— Wikipedia
CSS - Cascading Style Sheets (CSS) is a style sheet language used for describing the look and formatting of a document written in a markup language. Although most often used to change the style of web pages and user interfaces written in HTML and XHTML, the language can be applied to any kind of XML document, including plain XML, SVG and XUL. Along with HTML and JavaScript, CSS is a cornerstone technology used by most websites to create visually engaging webpages, user interfaces for web applications, and user interfaces for many mobile applications.
— Wikipedia
Liken to constructing a house, one might consider HTML the framing and CSS to be the painting & decorating.
