The core of this role is a web application that runs in the browser, written in JavaScript or TypeScript on top of a framework that organises the screen into components. React is that framework in most job posts, by a wide margin. Angular is second and lives in a particular kind of company: investment and lending software, medical devices, IT-management tools, the mid-sized IT services firms and Accenture, where long-lived business applications were built when Angular was the enterprise choice. Vue is a distant third and is rarely asked for on its own, though the travel sites and the customer-service platforms name it beside React. A fair share of job posts ask for more than one framework, usually React with Angular or Vue, which means the employer has screens built at different times and wants someone who can move between them. The consulting arms, the travel sites and the energy and chip companies ask this most. Plain JavaScript, HTML and CSS sit underneath every framework and are listed in a large share of job posts, because the engineer still has to understand what the framework is producing.
TypeScript is asked for in a large share of job posts, and the share tells you the kind of employer. It is close to universal at the travel sites and the product companies building business tools, common at the GCCs, and rare at Accenture and the staffing companies, whose job posts describe the work in general terms rather than naming tools.
A screen is built from components: a button, a form, a table, a card, each a small piece of code that draws one thing and can be reused. Component Architecture is the skill of deciding how those pieces fit together, and it is named in a good share of job posts. The harder problem is state: what the user has typed, what has been loaded, what is selected, and keeping every component in step when any of it changes. State Management is named about as often, and the tools for it follow the framework. Redux Toolkit is the most-named state library for React, with React Context API, React Hooks, Zustand and MobX behind it. NgRx and RxJS do the same job for Angular. A screen with many kinds of data on it, a help-desk console or a trading dashboard, is where these matter most, and the product companies building business tools ask for them most.
Larger organisations also ask for Micro Frontends, which split one big application into pieces that separate teams build and release on their own, and Web Components, which are components that work in any framework. Both appear at the GCCs and the business-tool companies, where many teams share one product.
The screen has to look right, and look right on every size of device. Responsive Design is one of the most-named skills in the whole role, and it means a layout that rearranges itself from a wide monitor to a phone. CSS does that work, and the tools on top of it appear in smaller shares: Sass and Less for writing CSS with variables and nesting, Tailwind CSS for styling with small utility classes, Bootstrap for ready-made layouts mostly in Angular work, and Styled Components and CSS-in-JS for styling inside React components. MUI appears as a ready-made React component library.
Many job posts also expect the engineer to work closely with design. UX Design and UI Design are named in a fair share, most of all at the product companies building business tools, where the engineer takes a design and turns it into a working screen and is expected to spot where it will not work. Figma is the design tool named. Design Systems and Storybook go together: a design system is the company's shared set of components and rules, and Storybook is the tool for building and showing them one at a time. These appear at the business-tool companies, the GCCs and the cybersecurity companies, where many screens have to look like one product.
The screen does not hold the data. It asks the server for it through a REST API, shows what comes back, and sends the user's changes back the same way. Fetching data, showing a loading state while it arrives, handling errors and keeping the screen in step with the server is a large part of everyday frontend work, and job posts assume it rather than list it. GraphQL appears in a minority of job posts, mostly at the GCCs and the newer product companies, where the screen asks for exactly the fields it needs from one endpoint. Node.js appears in a small share, and it means one of two things: either the engineer is expected to write a thin server layer that sits between the screen and the backend, or the job is drifting towards full-stack. Next.js is the clearest sign of the first, because it renders React pages on the server, which is what SSR means in the job posts. It is asked for most at the remote platforms, the construction companies and the newer product companies. A few job posts, mostly at the GCCs, also ask for SQL or a database, which is the employer wanting the engineer to be able to look at the data behind the screen.
A screen that is slow loses users, and a screen that cannot be used with a keyboard or a screen reader shuts people out. Frontend Performance is named in a fair share of job posts and most of all at the travel sites and streaming companies, where a booking flow or a video player has to be fast for millions of users and every delay costs sales. Core Web Vitals and Lighthouse are the measures and the tool for it, and Chrome DevTools is what the engineer uses to find out why a page is slow. SEO appears where the screen is public and has to be found by search engines.
Accessibility appears as WCAG, the standard, and as Accessibility Best Practices. It is named most at the GCCs of the banks and retailers and at the finance product companies, where the law or the customer requires it, and at the business-tool companies, where the product is used all day at work.
A frontend application is written as hundreds of small files and has to be turned into a few files the browser can download quickly. That is the job of a bundler. Webpack is the most-named, Vite is the newer and faster one, and Rollup and Babel appear beside them. npm manages the packages the application depends on. These tools are named most at the travel sites and the GCCs, and hardly at all at Accenture and the staffing companies.
A frontend application still has to be delivered to users, and that increasingly means the frontend engineer owning the route from code to a live site. Cloud is asked for in a fair share of job posts, AWS first, then Azure, then Google Cloud, and the services named are the ones a frontend touches: S3 and CloudFront for hosting and serving the files. Cloud is asked for most at the finance companies and the GCCs. A build-and-release pipeline is asked for in a good share of job posts, more at the GCCs and the business-tool companies than anywhere else. It runs the tests on every change, builds the bundle and publishes it, and GitHub Actions, Azure DevOps and Jenkins are named about equally, with GitLab CI behind them and SonarQube where code quality is checked in the pipeline. Docker and Kubernetes appear far less than in backend roles, because a built frontend is a set of static files rather than a running server.
Testing is the most-asked skill beyond the framework itself, named in a large share of job posts and in most of them at the business-tool companies, the finance companies and the GCCs. Two kinds appear. Unit tests check one component at a time, and Jest is the tool for React, with Mocha behind it and Jasmine and Karma for Angular. End-to-end tests drive the real screen in a real browser the way a user would, and Cypress and Playwright are the tools, with Selenium in a few older job posts. Testing is named least at Accenture and the staffing companies.
Once the screen is live, the team needs to know when it breaks for real users. Sentry is named for catching errors in the browser, and Core Web Vitals and Lighthouse for watching speed. These appear in a small share of job posts, and monitoring is a plus rather than a requirement in this role.
A small share of job posts ask for React Native, which lets a React engineer build a phone app from the same skills. It appears most at the travel sites and the GCCs. The Android SDK and iOS SDK appear in a handful of job posts, and Kotlin at one travel company.
A frontend engineer who knows React well in TypeScript, understands components and state with Redux Toolkit or a similar tool, writes CSS that works on any device, can fetch from a REST API and handle loading and errors, tests with Jest and Cypress or Playwright, and can build and ship through Webpack or Vite and a pipeline, meets the core of nearly every job post. The variations belong to the employer. The travel sites and streaming companies want speed above all, with Frontend Performance, Core Web Vitals and often a second framework. The business-tool companies want design sense, Design Systems, Storybook, Micro Frontends and the most testing. The finance companies want Angular with NgRx and RxJS, accessibility and a cloud. The GCCs want React almost exclusively, with Redux Toolkit, Jest, accessibility and a pipeline, and often a little Node.js and SQL. Accenture and the staffing companies describe the work in general terms, React or Angular with Responsive Design and State Management, and rarely name a tool beyond those.