Sr React JS Developer at KoinBX · Madurai · 5 - 7 years · ₹6L - ₹8L / yr · Profitable · Posted 22 Jan 2025

- Experience: 5+ years of professional experience in front-end development with a strong focus on React.js.
- Technical Skills: Proficiency in JavaScript (ES6+), HTML5, CSS3, and modern JavaScript frameworks/libraries.
- React Expertise: Deep understanding of React.js and its core principles, including hooks, context API, and state management.
- Tools: Experience with version control systems (e.g., Git), build tools (e.g., Webpack), and testing frameworks (e.g., Jest, React Testing Library).
Preferred Qualifications:
- Experience with: Knowledge of TypeScript, Redux, and modern front-end build pipelines and tools.
- Design: Familiarity with UI/UX design principles and responsive design.
- Blockchain: Understanding of blockchain technologies and cryptocurrency concepts is a plus.

About KoinBX
About
KoinBX is India's most trusted and fastest-growing crypto exchange, dedicated to providing a secure, compliant, and user-friendly platform for crypto enthusiasts and traders across India. As the most trusted and fastest-growing crypto exchange, KoinBX is your gateway to the future of finance, with a user-centric approach, advanced security measures, and an extensive array of cryptos. Our vision is to be the cornerstone of a future where every individual, regardless of background, discovers and harnesses the boundless opportunities of digital assets. KoinBX opens the doors to a future where digital assets play a transformative role in shaping the financial landscape. Our mission is to empower traders by offering a secure and trusted crypto trading platform that is easily accessible to all. We promise to be the gateway ushering in a future of limitless financial possibilities in the realm of digital assets. We provide advanced tools and confidence to navigate the Indian crypto market. We are proud to be 100% compliant with Indian regulations, safeguarding users' funds through robust security measures, including advanced encryption techniques and multi-factor authentication. With over 120 listed cryptos and 150+ active trading pairs, including cryptos like Bitcoin, Ethereum, and Ripple, we provide a comprehensive platform with an intuitive interface, real-time portfolio tracking, and timely price alerts for informed trading decisions. At KoinBX, we offer a wide suite of features designed to meet the diverse needs of both beginner and experienced traders. From instant KYC authentication to low trading fees and high liquidity, our platform is equipped with everything you need to trade cryptos. Join the 5 million+ strong crypto community on KoinBX and begin your crypto journey today. Whether you're a seasoned trader or just getting started, KoinBX is your trusted partner for all your cryptocurrency trading needs.
Candid answers by the company
KoinBX is your gateway to the future of finance, with a user-centric approach, advanced security measures, and an extensive array of cryptos.
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NEED TO HAVE :
1) Have some knowledge of front end like React.JS
2) HTML, CSS
3) Strong in JavaScript concepts
4) Good communication skills
5) Loves to code
GOOD TO HAVE :
1) Experience with type script will be a plus
2) Experience with Nest.JS framework will be a plus
3) Strong hold on ES6 principles.
4) Familiar with TDD ( Test Driven Development ) will be a plus.
5) Familiar with working in CI / CD will be a plus
6) Micro-Service architecture knowledge will be an added benefit.
You can contact me on this WhatsApp number: Nine three one six one two zero one three two
Role Summary
The Senior Front-end Developer builds and maintains client-facing interfaces per UI/UX designs and product requirements, owns front-end architecture and code-review standards, and mentors the Junior Front-end Developer. This is a specialized front-end role, not a full-stack position.
Key Responsibilities
• Own front-end architecture decisions, including framework, state management, and tooling choices.
• Set and enforce code-review, testing, and performance/accessibility standards for the pod.
• Lead implementation of complex, high-visibility features.
• Troubleshoot and resolve complex front-end performance or technical issues.
• Mentor the Junior Front-end Developer, including code review and skill development.
• Partner closely with UI/UX to ensure design fidelity and flag implementation constraints early.
• Evaluate and recommend front-end tooling or library upgrades.
Required Skills & Technical Competencies
• Deep expertise in a modern front-end framework (React strongly preferred) and associated ecosystem.
• Strong understanding of front-end performance optimization and accessibility standards.
• Experience owning front-end architecture for a production application.
Targeted Qualifications
• 5–8 years of front-end development experience.
• Deep expertise in a modern framework (React preferred) and front-end architecture patterns.
• Experience owning performance and accessibility standards.
• Bachelor's degree in Computer Science or related field.
Preferred / Nice-to-Have
• Experience with data-dense or real-time dashboard interfaces (relevant to IoT products).
• Experience mentoring junior developers formally.
The recruiter has not been active on this job recently. You may apply but please expect a delayed response.
Role Description
This is a full-time role for a React.js Developer who will be responsible for developing, maintaining, and optimizing responsive and scalable web applications. The successful candidate will work closely with UI/UX designers, backend developers, and product teams to convert designs and requirements into high-quality, production-ready applications. The role requires strong problem-solving skills, attention to detail, and the ability to take ownership of features from development through deployment.
Key Responsibilities
- Develop responsive and scalable web applications using React.js.
- Build reusable and maintainable frontend components.
- Convert UI/UX designs and Figma prototypes into functional web interfaces.
- Integrate frontend applications with REST APIs and backend services.
- Manage application state using Redux, Context API, Zustand, or similar technologies.
- Optimize applications for performance, responsiveness, and scalability.
- Debug and resolve frontend issues across development and production environments.
- Ensure cross-browser and cross-device compatibility.
- Collaborate with UI/UX designers, backend developers, QA, and product teams.
- Participate in code reviews and follow clean coding and development practices.
- Write and maintain appropriate tests for frontend applications.
- Stay updated with modern frontend technologies and best practices.
- Take ownership of features from development and testing through deployment and maintenance.
Requirements
- Strong proficiency in JavaScript (ES6+) and React.js.
- Good understanding of React Hooks, component architecture, props, state, and Context API.
- Strong knowledge of HTML5 and CSS3 and responsive web development.
- Experience integrating REST APIs and working with JSON.
- Experience with state management libraries such as Redux, Zustand, or similar.
- Experience with Git and GitHub/GitLab.
- Understanding of frontend performance optimization and browser debugging.
- 3+ years of hands-on experience in frontend development with React.js.
- Experience with TypeScript and Next.js is preferred.
- Familiarity with UI libraries such as Tailwind CSS, Material UI, or similar is a plus.
- Experience with frontend testing tools such as Jest, Vitest, or React Testing Library is a plus.
- Good problem-solving and analytical skills.
- Strong communication and collaboration skills.
- Ability to work independently, prioritize tasks, and meet deadlines.
- A proactive approach to learning and solving technical problems.
Candidates with strong practical experience, personal projects, GitHub contributions, or demonstrable frontend work may also be considered in place of extensive professional experience.
Job Description:
https://drive.google.com/file/d/12Fcie5u0rhyHeE_xhsNTeGk3mlPId1Mb/view?usp=drive_link
About NonStop io Technologies:
NonStop io Technologies is a value-driven company with a strong focus on process-oriented software engineering. We specialize in Product Development and have a decade's worth of experience in building web and mobile applications across various domains. NonStop io Technologies follows core principles that guide its operations and believes in staying invested in a product's vision for the long term. We are a small but proud
group of individuals who believe in the 'givers gain' philosophy and strive to provide value in order to seek value. We are committed to and specialize in building cutting-edge technology products and serving as trusted technology partners for startups and enterprises. We pride ourselves on fostering innovation, learning, and community engagement. Join us to work on impactful projects in a collaborative and vibrant environment
Brief Description:
NonStop io is seeking a proficient React.js developer to join our front-end development team. In this position, you’ll be mainly crafting and integrating UI components through React.js methodologies and workflows like Mobx and Redux.
Responsibilities:
● Developing and implementing UI components using React.js
● Collaborating with cross-functional teams to design and ship new features
● Building reusable components and front-end libraries for future use
● Translating designs and wireframes into high-quality code
● Optimizing components for maximum performance across various web browsers
● Troubleshooting and debugging issues to ensure smooth user experiences
● Participating in code reviews to maintain code quality and consistency
● Improvement and optimization of existing codebase
● Keeping up with industry trends
● Identifying issues with technologies and architecture and then implementing solutions
● Assist with ticket creation, refinement, and estimation
● Participate in sprint planning and ticket distribution for frontend team
Qualifications & Skills:
● Proficiency in React.js and its core principles
● Strong JavaScript, TypeScript, HTML5, and CSS3 skills
● Experience with popular React.js state management libraries and approaches (such as Mobx, Redux, and Context API)
● Familiarity with RESTful APIs and integration
● Knowledge of modern authorization mechanisms, such as JSON Web Tokens
● Understanding of front-end build tools and pipelines
● Familiarity with any one of backend technologies such as Node.js, Java, or Python
● Excellent problem-solving and communication skills
● A strong attention to detail, and a passion for delivering high-quality code
● Expertise in designing scalable and efficient front-end architecture
● Adaptability to changing project requirements and priorities
● Experience with version control systems, particularly Git
● Experience working in Scrum and familiarity with Atlassian (Jira, Confluence, Bitbucket)
● Experience with diverse applications and architectural patterns
● A degree in computer science, software engineering, or a related field
● Strong understanding of object-oriented programming principles and design patterns
● Familiarity with automated testing frameworks and methodologies
● Excellent problem-solving skills and attention to detail
● Strong communication skills and ability to work effectively in a collaborative team environment
● Ready to be a tech-agnostic engineer and comfortable to shift on any tech stack
● Comfortable working with AI (Claude code, Cursor etc)
If you're passionate about technology and want to work on impactful projects, we'd love to hear from you
About the team
SecurITe’s mission is to build an Agentic‑AI driven security platform that protects critical infrastructure from modern cyber threats. Our focus is on delivering highly performant, resilient, and intelligent network security systems that help defenders stay ahead of adversaries.
About the Role
We’re looking for an exceptional Front-End Developer to help lead the development of our next‑generation cybersecurity AI platform. This is a rare opportunity to shape how agentic AI transforms the future of cyber defense.
In this role, you will be instrumental in bringing our innovative Agentic graphical programming language to life. As a senior front-end developer, you will work closely with our systems architect to shape the technological direction of our project. Your responsibilities will include ensuring that our user interface is both functional and visually appealing, contributing to an exceptional user experience.
What You’ll Do
● Collaborate with the systems architect and development team to design and implement a robust front-end architecture.
● Develop, test, and maintain high-quality user interfaces using modern front-end technologies.
● Translate UI/UX design wireframes into code, producing visually appealing and user-friendly interfaces.
● Ensure the technical feasibility of UI/UX designs and optimize applications for maximum speed and scalability.
● Identify and troubleshoot front-end issues and implement effective solutions.
● Stay up-to-date with the latest industry trends and technologies to keep our product at the cutting edge.
● Own and drive project delivery end-to-end
● Guide and mentor other engineers to ensure high-quality code and best practices
Required Experience
● Proficiency in Languages HTML5, CSS3, and Angular 17+.
● Frameworks node.js, Flask, RESTful APIs, Strapi (CMS) ,Swagger/OpenAPI and related front-end technologies.
● Experience with front-end frameworks and libraries for Angular.
● Strong understanding of responsive design and mobile-first development.
● Knowledge of version control systems (e.g., Git).
● Excellent problem-solving and debugging skills.
● Strong communication and collaboration skills.
● Bachelor’s degree in Computer Science, Information Technology, or a related field.
● 15+ years of experience as a Front-end Developer, with a demonstrated track record in federal projects.
Nice to Have
● Advanced Skills: Experience with state management patterns (Redux, NgRx, Zustand) and building custom interactive components using SVG, Canvas, or libraries like GoJS, D3.js and React Flow.
● Experience working in cybersecurity products.
● Building enterprise UI/UX.
● Using AI for daily work.
● Early stage startup experience.
The Mindset
● Problem Solver: You thrive on complex, ambiguous challenges and engineer elegant solutions.
● Ownership‑Driven: You take initiative, move fast, and deliver outcomes without hand‑holding.
● Continuous Learner: You stay ahead of the curve in AI, ML, and emerging technologies.
● Startup DNA: You excel in fast‑moving environments where priorities evolve and impact is immediate.
We have an existing academic journal publishing and management platform developed using:
- Next.js
- React
- Node.js
- PostgreSQL
- REST APIs
The platform is already functional and includes author, reviewer, editorial and admin workflows.
We are looking for an experienced Senior Next.js Developer / Frontend Tech Lead to work on an existing production application.
The primary requirement is to redesign and rebuild the frontend while reusing the existing backend, APIs, database and business logic wherever technically feasible.
This is not a greenfield project and we do not want unnecessary rewriting of the existing backend.
Key Responsibilities
- Study and understand the existing Next.js application and architecture.
- Review existing APIs and backend integration.
- Develop a completely redesigned, professional academic/publishing frontend.
- Convert Figma designs into clean, responsive Next.js interfaces.
- Integrate the new frontend with existing Node.js APIs.
- Maintain existing workflows and functionality.
- Work on author, reviewer, editor and admin dashboards.
- Develop responsive interfaces for desktop, tablet and mobile.
- Improve frontend performance, usability and maintainability.
- Ensure proper authentication and role-based access handling.
- Identify frontend/backend dependencies that may require minor backend changes.
- Follow clean coding standards and reusable component architecture.
- Work through Git with proper commits, branches and code reviews.
- Coordinate with UI/UX designer and QA during development.
- Ensure the redesigned application is production-ready.
Existing Modules
The existing platform includes functionality such as:
- Author registration/login
- Manuscript submission
- Manuscript tracking
- Peer-review workflow
- Reviewer dashboard
- Editorial workflow
- Publication processing
- Payment-related workflows
- Article/publication management
- Journal management
- Certificates
- Referral/credit functionality
- Admin dashboard
- Reports and operational dashboards
The exact modules and workflows will be provided during the project.
Required Skills
Must Have
- 4+ years of professional React/Next.js experience
- Strong Next.js knowledge
- React + TypeScript
- JavaScript/TypeScript
- REST API integration
- HTML/CSS
- Responsive design
- Git/GitHub/GitLab
- Experience working with existing production codebases
- Good understanding of authentication and authorization
- Ability to understand backend APIs and database relationships
Good to Have
- Node.js
- PostgreSQL
- Tailwind CSS
- Next.js App Router
- Dashboard/SaaS application development
- Experience with complex multi-role applications
- Experience with academic, publishing, research or workflow-based platforms
What We Are Looking For
We are looking for someone who can understand an existing application before changing it.
You should be comfortable working with an existing codebase rather than expecting to rebuild everything from scratch.
Strong attention to:
- UI quality
- UX
- Performance
- Clean architecture
- Reusable components
- Security
- Cross-browser compatibility
- Maintainability
is required.
Important
- Existing backend and database should be reused wherever possible.
- Do not rewrite existing functionality without approval.
- Existing production data must not be modified or exposed.
- Development will be performed in a staging environment.
- Git-based development is mandatory.
- NDA and confidentiality agreement will be required.
- Ownership of the developed code and project deliverables will belong to the company.
Selection Process
Shortlisted candidates will first be asked to:
- Review the existing application architecture.
- Understand the existing APIs and workflows.
- Identify what can be reused and what needs modification.
- Complete a small paid technical task.
- Discuss the proposed development approach and timeline.
Candidates who demonstrate strong understanding of the existing system will be preferred.
Key Responsibilities
Frontend & Extension Development
• Build and maintain highly responsive, modern user interfaces using React.js for web applications, browser extensions, and Electron-based desktop clients.
• Architect and develop modular, reusable UI components using Material-UI (MUI / Joy UI) and styled-components/Emotion.
• Manage complex multi-target build pipelines (Web, Extension, Electron) using Webpack and Craco.
AI Integration & Engineering
• Seamlessly integrate Generative AI capabilities into the frontend, including AI-driven chatbots, contextual AI suggestions, and RAG (Retrieval-Augmented Generation) interfaces.
• Collaborate closely with backend and AI specialists to consume AI-powered REST APIs and WebSocket streams, ensuring fluid and responsive user experiences.
• Implement robust markdown and code rendering (e.g., react-markdown) for rich AI conversational outputs.
Real-Time Data & State Management
• Implement low-latency, real-time communication features using Socket.IO for chat and collaborative functions.
• Efficiently manage complex application state, data fetching, and caching using modern tools like React Query and Axios.
Quality & Collaboration
• Work within a monorepo/workspace structure to maintain distinct client, component, and extension packages.
• Participate in code reviews to maintain high code quality, performance, and enterprise security standards.
• Collaborate with teams using Agile/Scrum methodologies for rapid and structured delivery.
Required Skills:
• Core Languages: Proficiency in JavaScript (ES6+) and TypeScript.
• Frontend Frameworks: Strong, hands-on experience with React.js (Hooks, Context), React Query, and React Router.
• Styling & UI: Deep understanding of HTML5, CSS3, and CSS-in-JS libraries (e.g., styled-components, react-jss). Hands-on experience with MUI (Material UI / Joy UI) is highly preferred.
• Architecture & Build: Experience configuring and optimizing builds with Webpack and Craco. Familiarity with npm workspaces/monorepos.
• Real-time & APIs: Ability to design and implement robust client-side integrations with RESTful APIs and WebSockets (Socket.IO).
• Agile & Workflow: Experience working with Agile and Scrum methodologies.
Preferred/Bonus Skills:
• Experience in building and packaging Browser Extensions and/or Electron applications.
• Genuine curiosity and awareness of Generative AI workflows (e.g., prompt engineering concepts, handling streaming AI responses).
• Experience with rich text editing or markdown rendering in React.
Frontend Developers
- Contract To Hire (Initial Engagement: 6 months)
Experience: 5+ years
Mandatory Skills:
● React.js
● React Native
● JavaScript
● Experience in developing scalable and maintainable web and mobile applications
● Frontend architecture and reusable components
● State management
● REST API/backend service integration
● Application performance optimisation
● Authentication/authorisation and frontend security
● Git and pull-request-based development
● Clean, reusable and testable code
● Agile/product development experience
● Code reviews, debugging and production issue resolution
Good to have:
● TypeScript
● Next.js
● Jest / React Testing Library
● CI/CD
● Application monitoring
● Mobile deployment
The recruiter has not been active on this job recently. You may apply but please expect a delayed response.
We are looking for a Full Stack Developer to produce scalable software solutions. You'll be part of a cross-functional team that's responsible for the full software development life cycle(Java with react), from conception to deployment.
- Responsible for developing software in Java, object-oriented databases, and the dotCMS platform.
- Responsible for building REST web services, and designing interfaces between UI and REST service.
- Deep knowledge and hands-on experience with Java and UI stack.
- Proficient experience with web technologies, frameworks, and tools like HTML, CSS, JavaScript, React, NodeJS, XML, jQuery, Spring, etc.
- Should be well versed with State Management, Redux, Reducers, JavaScript, and CSS in ReactJS/UI.






