React.js Developer

Frontend Engineer

React, TypeScript & Production Web Applications

📍 Mumbai (On-site) | Full-time | 3-5 years

About the Role:

Unico Connect is an AI-first technology partner that builds custom mobile, web, and AI products for clients across multiple geographies.

We are hiring a Frontend Engineer who will build production-grade web applications across customer engagements, partnering closely with designers, backend engineers, and AI engineers.

The mandatory requirement for this role is hands-on production experience shipping React applications, with ownership of at least one feature area end to end including state, API integration, and testing.

The role is hands-on.

Expect to implement complex flows, integrate with backend and AI services, contribute to a shared design system, write tests, and review the work of others.

A typical week includes a design handoff review, implementation of a new flow, a code review session, and a working call with a backend engineer on API contracts.

Responsibilities:

Production UI Development

Build production-grade React UI for customer engagements, including complex forms, dashboards, data-dense views, and AI-driven interactions.

API Integration

Integrate with REST and GraphQL APIs.

Handle authentication, streaming responses (Server-Sent Events, WebSockets), retries, and graceful error states.

State Management

Build state architecture using Redux, Zustand, Jotai, or equivalent.

Handle async state, optimistic updates, and cross-component coordination.

Design System Contribution

Implement components within an established design system.

Maintain token discipline and contribute back to shared components.

Testing

Write unit, integration, and end-to-end tests using Jest, React Testing Library, and Playwright or Cypress.

Performance and Accessibility

Profile and optimise rendering and bundle size.

Apply WCAG 2.1 AA practices in everyday work.

AI-Assisted Development

Use Claude, Cursor, and similar tools day to day.

Build discipline for reviewing and validating AI-generated code.

Requirements:

Hands-on Production React Experience (Mandatory)

Must have personally shipped at least one feature area end to end in a production React application, owning state, API integration, and testing.

POCs and internal tools alone do not qualify.

3 to 5 Years of Professional Frontend Engineering Experience

Strong JavaScript, TypeScript, and React

Solid with hooks, context, and modern patterns.

Working comfort with Next.js (SSR, SSG, app router).

State Management

Production experience with Redux, Zustand, Jotai, or equivalent.

CSS and Styling

Strong with Tailwind, CSS Modules, or CSS-in-JS.

Comfortable building responsive layouts.

REST and GraphQL

Comfortable consuming both.

Working knowledge of streaming responses and async patterns.

Testing Fluency

Jest, React Testing Library, and at least one of Playwright or Cypress.

Git and CI/CD Basics

Comfortable with feature branching, pull requests, and CI-integrated test runs.

Strong Written and Spoken English Communication

Nice to Have:

• Experience with editor or canvas UIs
• Storybook
• Animation libraries (Framer Motion, GSAP)
• Exposure to AI-driven UI patterns
• Visual regression testing tools

About Company: 

Espressif Systems (688018) is a public multinational, fabless semiconductor company established in 2008, with headquarters in Shanghai and offices in Greater China, India, and Europe. We have a passionate team of engineers and scientists from all over the world, focused on developing cutting-edge Wi-Fi and Bluetooth, low-power IoT solutions. We have created the popular ESP8266 and ESP32 series of chips, modules, and development boards. By leveraging wireless computing, we provide green, versatile, and cost-effective chipsets. We have always been committed to offering IoT solutions that are secure, robust, and power-efficient. By open-sourcing our technology, we aim to enable developers to use Espressif’s technology globally and build smart connected devices. In July 2019, Espressif made its Initial Public Offering on the Sci-Tech Innovation Board (STAR) of the Shanghai Stock Exchange (SSE). 

Espressif has a technology centre in Pune. The focus is on embedded software engineering and IoT solutions for our growing customers.

About Role: 

https://rainmaker.espressif.com/">ESP RainMaker provides a complete solution to makers to develop connected devices with ease. It also focuses on solving a major challenge about how the quality of connected devices can be improved. It constitutes device-side SDK, mobile apps and a cloud application. This role requires product engineering for the web UI for the RainMaker cloud.

Minimum Qualification: 

• BE/B.Tech in Computer Science with 5 to 10 years of experience
• Strong Computer Science Fundamentals

• Excellent understanding of UX and design sensibilities

• Design, develop, and test UI for web applications
• Experience with one or more of these: React, Redux, Webpack, ES6, Async JS Communication, WebSockets
• Strong debugging and troubleshooting skills
  
  

Desired Qualification:

• Significant experience with JavaScript, React and Redux.
• Experience in consumption of cloud services and REST interfaces (implementation experience would be added advantage)
• Experience with CSS pre-processors like LESS or SASS
• Expertise with cross-browser, cross-platform, and responsive design
• Solid understanding of user interactions required for Single-Page Applications
• Experience with modern browser technologies

Responsibilities: 

• Designing and developing User Interface for web applications
• Write code based in HTML, CSS, JavaScript and ReactJS
• Accurately translate user and business needs into functional, secure and efficient frontend design and code
• Experience and desire to take product/feature ownership from delivery and customer support perspective
• Collaborate with backend and quality engineers to spec, write, test, and deploy code that integrates with data streams and API endpoints
• Utilise responsive design techniques and ensure cross-browser compatibility
• Perform code reviews and improve/ensure the quality of product

What to expect from our interview process

• The first step is to email your resume or apply to the relevant open position, along with a sample of something you have worked on such as a public GitHub repo or side project etc.
• Next, post shortlisting your profile recruiter will get in touch with you via a mechanism that works for you e.g. via email, phone. This will be a short chat to learn more about your background and interests, to share more about the job and Espressif, and to answer any initial questions you have.
• Successful candidates will then be invited for 2 to 3 rounds of the technical interview as per the previous round feedback.
• Finally, Successful candidates will have an interview with HR.

What you offer us

• Ability to provide technical solutions, support that fosters collaboration and innovation.
• Ability to balance a variety of technical needs and priorities according to Espressif’s growing needs.

What we offer

• An open-minded, collaboration culture of enthusiastic technologist.
• Competitive salary
• 100% company paid medical/dental/vision/life coverage
• Frequent training by experienced colleagues and chances to take international trips, attend exhibitions, technical meetups and seminars.

responsibilities

• Develop User interfaces for Modern Rich Internet Applications with the latest Front End Technologies
• Perform product analysis and development tasks of increasingly complex nature which may require extensive research and analysis.
• Writing tested and documented JavaScript, HTML and CSS
• Make design and technical decisions for AngularJS projects.
• Develop application code and unit test in the AngularJS, Rest Web Services and Java technologies for the Application Development Center. 
• Ensuring high performance

requirements

• Strong expertise with HTML, CSS, and writing cross-browser compatible code.
• Good understanding of AJAX and JavaScript Dom manipulation Techniques
• Experience with RESTful services
• Experience in JavaScript build tools like grunt or gulp
• Expert in any one of the modern JavaScript MV-VM/MVC frameworks (AngularJS, JQuery, NodeJS, GruntJS)
• Familiar with testing frameworks (Ex. Jasmine)
• Test runner framework (Ex. Karma)
• Hand on and implements complex AngularJS applications, directives, controllers, services
• Critical thinker and problem-solving skills
• Team player
• Good time-management skills
• Great interpersonal and communication skills

Benefits:

• 5 days working
• Paid Overtime 
• Paid Leave
• Employee referral scheme
• Team exposure
• Short term growth
• Playing Zone
• Training sessions for all departments

Job Responsibilities:

• Collaboratively work with UX team, product managers, back-end engineers and other technical teams to create new, delightful and scalable UI
• Mentor junior members through training and individual support
• Responsible for all front end development on a project
• Ensure the technical feasibility of UI/UX designs
• Optimize application for maximum speed and scalability
• Identify and troubleshoot UX problems (e.g. responsiveness)
• Conduct layout adjustments based on user feedback
• Adhere to style standards on fonts, colors and images
• Optimize existing user interface designs
• Proactively learn and accordingly apply new technologies, best design practices and usability patterns

The ideal candidate must - 

• 5+ years of experience working with React or React-based frameworks
• Proficiency with browser-based debugging and performance testing
• Proficiency in Git and version control
• Considerable experience with a testing framework (Jest/Mocha)
• Familiarity with RESTful APIs and GraphQL
• Knowledge of modern authorization mechanisms, such as JWT Tokens
• Good understanding of common front-end development tools such as Babel, Webpack, NPM, Yarn etc
• Hands-on experience with CSS-in-JS libraries
• Proficient understanding of cross-browser compatibility issues and ways to work around them
• Keen to learn, mentor and willingness to take ownership of work items
• Possess strong communication and self-accountability