Freelance React.JS developer

Role Overview

We’re hiring a Senior Frontend Engineer with 5+ years of experience to build high-performance, scalable, and visually refined web applications. This is a hands-on engineering role focused on architecture, performance, and crafting exceptional user experiences across modern browsers and devices.

You will work closely with design, product, and backend teams to build robust frontend systems, define engineering standards, and ship production-grade features that scale.

What You’ll Build

1. Frontend Architecture & Development

• Build scalable, modular frontend applications using modern JavaScript frameworks
• Architect component-driven UI systems and reusable design libraries
• Implement robust state management and data flow patterns
• Develop responsive, cross-browser experiences with high usability
• Collaborate with backend teams to design API contracts and integrations

2. Performance & Optimization

• Optimize applications for speed, scalability, and accessibility
• Improve Core Web Vitals and page load performance
• Implement code splitting, lazy loading, caching, and asset optimization
• Diagnose and resolve performance bottlenecks in production environments
• Ensure smooth user experiences across low-end to high-end devices

3. UI Engineering & Design Systems

• Build and maintain scalable design systems and component libraries
• Translate Figma or design specifications into pixel-perfect interfaces
• Implement accessibility standards (WCAG) and responsive layouts
• Maintain visual consistency across products and platforms

4. Frontend Platform & Tooling

• Improve build systems, CI/CD pipelines, and developer tooling
• Implement testing strategies including unit, integration, and end-to-end testing
• Establish coding standards, linting rules, and documentation practices
• Support deployment workflows and release management

5. Collaboration & Leadership

• Mentor junior engineers and conduct technical reviews
• Work with product and UX teams to shape user-facing features
• Contribute to technical decision-making and roadmap planning
• Advocate for performance, maintainability, and user-centric design

Technical Stack

Frontend

• JavaScript / TypeScript
• React, Next.js (or similar modern frameworks)
• HTML5, CSS3, Tailwind or CSS Modules
• State management libraries such as Redux, Zustand, or similar

Tooling & Platforms

• Webpack, Vite, Rollup
• Git-based workflows
• Testing frameworks such as Jest, Cypress, Playwright
• REST APIs and GraphQL

Performance & Quality

• Chrome DevTools and performance profiling
• Accessibility tools and audits
• CI/CD pipelines and monitoring tools

What We’re Looking For

Must-Haves

• 5+ years of experience in frontend engineering
• Strong expertise in JavaScript or TypeScript and modern frameworks
• Experience building scalable frontend architecture from scratch
• Deep understanding of browser rendering, performance, and optimization
• Strong grasp of responsive design and accessibility best practices
• Experience integrating APIs and working closely with backend teams
• Ability to write clean, maintainable, and production-ready code

Highly Desirable

• Experience building design systems or UI platforms
• Familiarity with SSR or SSG and performance-driven architectures
• Experience with micro-frontends or large-scale frontend systems
• Exposure to cloud deployment workflows and frontend observability
• Product-focused mindset with strong UX understanding

Technical Challenges You’ll Tackle

• Scaling frontend architecture for complex applications
• Maintaining performance across devices and network conditions
• Designing reusable UI systems across multiple products
• Improving developer productivity and build pipelines
• Ensuring accessibility and usability at scale

Why Join Ctruh

• Work on product-focused engineering, not just UI implementation
• Build systems that directly impact customer experience and engagement
• Ownership of architecture, performance, and engineering standards
• Small, high-caliber engineering team with strong technical depth
• Freedom to experiment and influence product direction

Location & Work Culture

• Work from office: HSR Layout, Bengaluru
• 6-day work week (5 days in office, Saturdays work-from-home)
• High-performance engineering culture
• Fast decision-making environment with strong ownership mindset

Ideal Candidate Profile

• You think in systems, not just components. You care about performance, scalability, and user experience equally.
• You have built production-grade frontend applications, improved engineering standards, and mentored teams.
• You write maintainable code, challenge assumptions, and take ownership of the user journey end-to-end.

Front end Developer (Angular)

- You are your own master. We don't preach you, we just allow you to Innovate, Iterate, Learn and Adapt

- Work with one of India's leading fintech unicorn company

- ESOPs in the company

Requirements

- At least 3-12 years of Frontend development experience

- BE/BS in Computer Science, Management and Information Systems, or equivalent

- Problem Solver: Ability to formulate/implement technical solutions, proven ability to understand, analyze, and

solve issues with guidance.

- Should have executed a production level end to end UI application on his own

- A hands-on contributor who played an important role in implementing the proposed architecture and design

- Excellent command over HTML5, CSS,Javascript,Jquery,Ajax,MVVM. Proficient understanding of web markup.

- Expert Level proficiency of Bootstrap, Angular.js (Angular Latest version preferred), Framework.

- General Familiarity with Node.js, Ember.js, Can.js, React.js

- Proficient in unit test cases for UI applications functionality and flow testing using Jasmine/Karma Framework

- Good knowledge of caching and memory management for UI applications

- Exposure to data visualization libraries such as D3.js

Roles and Responsibilities

- Collaborate with cross-functional teams to define, design, and push new features and innovative front-end

solutions. Translate UI/UX design wireframes to actual code that will produce visual elements of the application.

- Continuously discovering, evaluating, and implementing new technologies to maximize development efficiency.

- Provide technical leadership towards new UI architectures.

- Unit-testing code for robustness, including edge cases, usability, and general reliability.

- Create and be accountable for user interaction models, workflows, information architecture, prototypes, and

guidelines for user interfaces.

- Work closely and collaborate with other members of the development teams to ensure smooth integration of the UI component with back end technologies

- Designing and building responsive web applications.

The developer will be responsible to build and enhance collaboration functionalities in our products while ensuring seamless user interaction in the platform. Our engineering team works on developing a range of innovative products to facilitate regulatory work flow of medical device companies. An ideal candidate is one willing to work in a tight schedule of a start-up and experienced in building magical user experiences and considers performance to be the key metric in the application.

Responsibilities :

• Develop new features using Angular 9/10
• Develop reusable components
• Write efficient and documented object oriented code
• Write extensive unit test cases and execute them
• Ensure responsive design of the front end

Skills and Qualifications :

• 2-5 years experience in developing web based applications and building product product from scratch

• Detailed understanding of coding and design aspects of Angular 9/10

• Proficiency with Observables, NGRX and websockets

• Knowledge of various Angular/Jquery packages

• Knowledge of Responsive Design

• Knowledge of WYSIWYG editors

• Knowledge of different performance optimization techniques

• Experienced in various data structures and design patterns

• Knowledge of asynchronous programming

• Bachelor’s Degree in computer science or equivalent education.

• Developing new user-facing features using React.js.
• Build reusable components and front-end libraries for future use.
• Translate designs and wireframes into high-quality code.
• Optimize components for maximum performance across a vast array of web-capable devices and browsers.
• Design a modern highly responsive web-based user interface.

Skills and Competencies;

• Bachelor's degree in computer science preferred.
• 3-5 years of demonstrated experience.
• Good knowledge of HTML5, CSS3.
• Strong proficiency in Javascript.
• Strong working knowledge of React JS and web apps.
• Good working experience using API in UI development.
• Should be able to do responsive design and cross-browser compatibility.
• Willingness to experiment and take complete responsibility for projects.
• Work independently and remote, with excellent follow-up, time management, and organization skills.
• Any additional knowledge of/familiarity with programming, in general, would be a great added bonus.
• Knowledge of Jira/confluence.
• Familiarity with code versioning tools such as Git.
• A team player with a problem-solving aptitude.
• Fluent in a second language preferred, good level of verbal English required.

Mentor To Go is an android and web based platform to help students improve their work readiness through self-learning sessions, personalised mentorship provided by mentor professionals from a range of careers, and work experience opportunities.

The technology platform implements  functionalities such as: screening surveys of mentors and mentees, training content for mentors, matching through an algorithm, and mentorship through the delivery of structured activities. 

The application technology architecture comprises of the following:

o   a Python Django web application with NGinx and Gunicorn

o   PostgreSQL database

o   A React Android and Web app

o   Rest APIs which interact between the Android app and the Django webserver

Our vision at Mentor To Go is to provide career mentorship to young people anywhere, anytime across the length and breadth of India.

We are looking for a frontend software developer who is passionate about using web technologies to solve social problems and creating experiences that are elegant and effective.    You will own the front end development of features  of the Mentor To Go web and mobile platforms, from conceptualisation through design and testing. You will work closely with other developers,the technical project manager, and the program operations team. You are user-centric, continuously demonstrate strategic & analytical abilities, and are laser focused on executing at speed. You must have the ability to succeed in a fast paced environment, where success is dependent on your ability to collaborate with cross-functional team members  in a positive, productive, and transparent way.

Minimum requirements

• Bachelor’s degree in engineering preferably  CS  or related discipline
• 3+ years experience with the development of applications for Android, iOS and  web preferably using React Native/ReactJS

• Experience working in Unix/Linux environments
• Experience with a complete mobile software development life cycle
• Strong written and oral communication skills
• Familiarity with version control software such as Git

Desired  requirements

• Strong written and oral communication skills
• Ability to participate in technical discussions and help make technical trade-offs

About Mentor Together

https://mentortogether.org/">Mentor Together is India’s first and largest youth mentoring  non-profit organization with a mission to facilitate empowering mentoring relationships and networks that help young people break the inequalities of opportunity and actualise their potential.

http://bit.ly/mentortogo">Mentor To Go is the world’s first mobile mentoring platform created by Mentor Together with the support of Cisco India, LinkedIn Social Impact, British Telecom and Sterlite Technologies.

At Quantela, we’re revolutionizing the way cities are operated and managed. We are making autonomous cities a reality, where citizens will lead a better quality of life by experiencing the power of real time connected urban infrastructure. We are an Artificial Intelligence based software company and a leader in the global Smart Cities and Communities market. We are focused on the intelligence behind every city – our platform optimizes urban infrastructure through data-driven recommendations and automation of standard operating procedures.

Our customers include cities, communities, ports, airports, universities, roads, utilities, campuses, etc. Many industry-leading technology companies, urban operators, and system integrators utilize our platform to deliver tangible outcomes to their customers.

About the role

Quantela is seeking UI Architect who is proficient in design and development of web based front end applications for enterprises.

Qualifications:

• Should have sound understanding of Object-Oriented JavaScript & Typescript concepts and Debugging skills.
• Should have strong Implementation & architectural design skill of BOTH client-side and Server-side NodeJS/JavaScript (and related frameworks) based application
• Should build reusable code and libraries for future use
• Should have working experience on Angular (Preferably at least 3+ year experience in Angular 5 and above versions), HTML5, CSS3.
• Should be able to recommend appropriate UI frameworks and controls, design and develop web applications based upon a set of requirements
• Responsible for setting coding standards using best practices/principles and ensuring its adherence
• Good understanding of UI best practices, RESTful services, Accessibility WCAG 2.0, etc.
• Should be able to understand security models like OWASP standards
• The selected candidate should be an evangelist, self-driven, visionary leader and mentor
• Must have excellent written and verbal communication skill and a positive attitude
• Should preferably have product development experience.

Ideal Candidate should have:

• Extensive knowledge of Object-Oriented JavaScript, TypeScript, HTML5, CSS3
• Extensive knowledge in Angular
• Hands on knowledge on ng-cli, ngrx, rxJS and schematics
• Hands-on experience in using template engines like Mustache / Handlebars/Blaze etc
• Proficiency in Clarity CSS, SASS and CSS pre-processors (SASS, LESS etc)
• Extensive knowledge in implementing responsive cross-browser user experiences
• Extensive knowledge in Ajax, and consuming RESTful web services
• Extensive knowledge in ES6
• Unit testing frameworks like Jasmine/Chai/Mocha/Karma
• Performance evaluation using Chrome dev tools etc, W3C standards
• Understanding of complete Technology Stack of application (Integrations with downstream Applications/Services, Deployment, Cloud Infrastructure & Services, CI/CD pipeline)
• Knowledge in design patterns on UI
• Good to have knowledge on Monorepo concept
• Knowledge or Should have worked on enterprise class applications
• Should have worked in Agile environment