In recent years, startups hire a team of full-stack developers because they want to work with defined resources. Startups get the initial lift if the organization can operate on front-end and backend both toward a product development or a web application. As a startup, you can't afford to choose a person for only one skill; you want people who work the various tasks. Instead, hire for HTML developer-only, why not hire somebody who can work with CSS/HTML, Angularjs development, and able to connect with the database as well. For organizations like Facebook, Twitter,  Google, they look for confident front end developer-angularjs consultant, UX team, server-side team, database team, etc. So they usually hire a professional who has expertise in one particular skill. eventually, people specialize, a person who was spending his time for PSD design, developing the Angularjs code, sometimes working with API, will ultimately become specialize at least in one area, i.e., Professional Angularjs Developer

Here are various functional or skill domains on a full-stack web engineering team: 

1. UX Designer

UX designers are accountable for the user satisfaction with web product or application by providing the accessibility, usability, and joy of interaction with a web application. They usually start with requirement gathering from the stakeholder of the web application and maps the user navigation, find the user's persona and data architecture. Uses the Invision, Axure, or Balsamiq to design the wireframe and prototype. They can develop the complete clickable prototype of the web application before starting the project to make sure the user experience on each page of the web product or application.

2. Visual Designer

They are perfect in illustrator, photoshop, and sketch and gives the slices or PSD assets; you can evaluate his portfolio over Behance and Dribbble – the designer’s community.

3. Front-end Developer

the front developer utilizes the Slices PSD and changes it into the HTML+CSS with media/jquery query to make it mobile and browser responsive. Front end developer creates the web application active in the browser; now, they frequently use the front-end framework like Vue.js/Angularjs/react js. The job title includes  "Software engineer," "Front end developer," "UI engineer." 

4. Backend Developer

Writes server-side code like node.js, and PHP, as well as web frameworks like Express, Laravel, CodeIgniter.The Entry-level backend developer develops the dynamic web pages and interaction using a database like (MongoDB/MySQL)Skillful level backend developer uses the various databases to keep the application data as needed. They understand the scalability of data, performance, and high-level architecture for future expansion works with the database like  MongoDB, MySQL, Redis, Neo4j, and PostgreSQL, etc.

Cloud hosting engineer

Nowadays, system admin positions drastically altered towards the cloud hosting specialist due to the popularity of the critical player like AWS, Google cloud, and digital oceans for serverless architecture. As per the new trend professional's level, Full stack developer acquiring this cloud hosting skill as well.