Lead Engineer - Frontend

Front-End Developer (React.js) – Mumbai | Immediate Joiners

Location: Mumbai

Experience: 2+ Years

Job Type: Full-Time

Notice Period: Immediate Joiners Only

About the Role

We are hiring a Front-End Developer to join our product engineering team. The ideal candidate has experience working in product-based companies and has contributed to at least one end-to-end e-commerce platform project.

Key Responsibilities

• Develop and maintain responsive UIs using React.js
• Convert UI/UX designs into reusable front-end components
• Optimize components for performance and cross-browser compatibility
• Integrate front-end with backend RESTful APIs
• Collaborate with product, design, QA, and backend teams
• Participate in code reviews, agile ceremonies, and testing

Required Skills

• Strong in JavaScript (ES6+), React.js, HTML5, CSS3
• Experience with Redux/Zustand for state management
• Knowledge of REST APIs, responsive design, and Git
• Familiarity with debugging and front-end performance optimization

We are seeking a highly motivated Software Development Engineer with expertise in building scalable, extensible and user-friendly web applications. You will work with a fast paced Product Engineering team to build efficient and reusable web applications for mobile and fixed devices. 

What you’ll do:

• Architect, Design, Code reviews and build scalable applications.
• You will be engaged in identifying and addressing performance bottlenecks, and collaborate with other team members to innovate current/new products. 
• Identify, communicate and implement best practices for application engineering. 
• Ensure high scalability and performance

• You will advocate for good, clean, well-documented and performing code; define and follow standards and best practices for front-end development.

We’d love for you to have:

• Experience: 1-3 yrs recent experience of working in a scalable web product firm
• Education: B.Tech/M.Tech  in Computer Science from Top ranked colleges in India
• Excellent software development skills in developing web applications over client-side frameworks - Backbone, React (preferred) and/or angular frameworks (preferred); and server-side frameworks like node.js
• Excellent programming skills in object-oriented, modularised JavaScript, Typescript (preferred)
• Strong knowledge and working experience in server-side Event-driven programming using Node.js
• Excellent programming skills in Javascript,  jQuery, AJAX, YUI.
• Passion for writing optimized code using JS best practices  and design patterns
• Experience with JS or Java-based Unit/Integration Testing using Selenium, Appium, Selendroid
• Hands-on experience in building scalable web applications
• Excellent problem solving and debugging skills
• Good Knowledge of version control - GIT (preferred)
• Experience with the full software development lifecycle, design, develop, debug, document, and deliver (especially in a multiple site organization)
• Strong verbal and written communication skills
• Ability to deliver great results in an agile development
• Good to have: Working knowledge of web standards (i.e., REST) and OOPS
• Good to have: Experience in Data Structures, Algorithms and their optimization

Even if you don’t meet all of these qualifications above, we’d still love to hear from you. Tell us about your unique qualifications in your cover letter.

CaaStle is committed to equality of opportunity in employment. It has been and will continue to be the policy of CaaStle to provide full and equal employment opportunities to all employees and candidates for employment without regard to race, color, religion, national or ethnic origin, veteran status, age, sexual orientation, gender identity, or physical or mental disability. This policy applies to all terms, conditions and privileges of employment, such as those pertaining to training, transfer, promotion, compensation and recreational programs.

Position Overview: We are seeking a talented and motivated ReactJS Intern to join our team for a 6-month full-time internship. This is a fantastic opportunity for someone with prior internship experience to deepen their knowledge and skills in ReactJS while working on cutting-edge projects.

Responsibilities:

• Collaborate with the development team to design, develop, and maintain web applications using ReactJS.
• Write clean, maintainable, and efficient code.
• Participate in code reviews and contribute to the improvement of the codebase.
• Work closely with designers to implement user interfaces and user experiences.
• Assist in troubleshooting, debugging, and optimizing applications.
• Stay updated with the latest industry trends and technologies related to ReactJS.
• Contribute to the documentation of technical processes and workflows.
• Engage in team meetings and brainstorming sessions to contribute innovative ideas.

Requirements:

• Previous internship experience in a software development role.
• Knowledge of ReactJS and its core principles.
• Proficiency in JavaScript, HTML5, and CSS3.
• Familiarity with RESTful APIs and asynchronous request handling.
• Understanding of modern front-end build pipelines and tools.
• Experience with version control systems, preferably Git.
• Excellent problem-solving skills and attention to detail.
• Ability to work effectively in a collaborative team environment.
• Strong communication skills and the ability to articulate technical concepts clearly.

Nice to Have:

• Understanding with state management libraries like Redux or Context API.
• Knowledge of TypeScript and its integration with ReactJS.
• Familiarity with front-end testing frameworks and tools (e.g., Jest, Enzyme).
• Understanding of responsive design principles and mobile-first development.
• Experience with CSS preprocessors like SASS or LESS.

What We Offer:

• Hands-on experience with real-world projects and modern technologies.
• Mentorship and guidance from experienced professionals.
• A collaborative and inclusive work environment.
• Opportunity to contribute to meaningful projects and make a real impact.
• Competitive stipend and potential for a full-time position upon successful completion of the internship.

Location: Bangalore, Delhi, Gurgaon

Function: Software Engineering → Frontend Development

Requirements:

• 2-5 years of experience in building large complex and performant web applications using JavaScript, HTML, and CSS across multiple browsers.
• Strong Object Oriented JavaScript fundamentals.
• Experience in java script frameworks such as React and a good understanding of the basics of these frameworks and their life cycles.
• Deep understanding of various deployment strategies and their pros and cons.
• Understanding of Docker.
• SSR experience is a must.
• You should have enough understanding of SEO principles.
• Experience of working with React Hooks desirable.
• Experience with popular React.js workflows (such as Flux or Redux).
• Familiarity with newer specifications of ECMAScript (ES6 ES7).
• Experience with server-side rendering using nextjs, express, hapi etc.
• Hands-on experience with any unit testing framework (mocha/chai, jest etc).
• Deeper understanding of Chrome Dev Tools.
• Should understand nuances of the timeline for perf monitoring.
• Deeper knowledge of UI optimizations and performance.
• Deeper understanding of network layer, HTTP, HTTPS, cookies, local storage.
• Understanding of JavaScript Design patterns and ability to use them in applicable scenarios.
• Good understanding of data structures and algorithms and their space and time complexities.
• Strong in open source technologies, agile development.
• Excellent communication skills, good visual design sense, in-depth experience in developing web-based applications.
• Familiarity with code versioning tools such as Git, SVN, and Mercurial.

Web Development Interview:

• Technical Round 1 JS + Web fundamentals + React (Based on Experience)
• Technical Round 2 React JS - Problem solving (Machine coding round)
• Technical Round 3 Technical evaluation/Team fitment
• HR Round

• Observe, strategize, develop and design user-friendly UI/UX using markup languages like HTML.
• Designing Client-Side and Server-Side Architecture and Rendering and Static Site Generation.
• To confer with users - by studying systems flow, data usage & work related bottlenecks.
• Design and implement Front-End code
• Interact with the production team, understand their workflow and find new ways to visualize their workflows on web apps.
• Integrating Python Scripts with Python-based UI interfaces like Dash and Flask.
• Maintain and improve web-app
• Optimize applications for maximum speed
• Create quality mockups and prototypes
• Design mobile-based features
• Integrating APIs with front-end user interfaces.
• Build features and applications with a mobile responsive design
• Write functional requirement documents and guides
• Work with data scientists and analysts to visualize their analysis reports
• Help back-end developers with coding and troubleshooting
• Ensure high-quality graphic standards and brand consistency
• Stay up-to-date on emerging technologies

• Strong Knowledge of HTML, CSS, Bootstrap, JavaScript, AJAX, jQuery and Prototyping.
• Strong knowledge of client-side dynamic and rich UI applications development.
• Hands-on experience in C#, Python, .Net
• Strong hands-on experience in popular frameworks and JavaScript ecosystem – JS, Node, Angular, Jquery.
• Experience in Spark, Hadoop, Scala, and Elastic Search is a plus point.
• Familiarity with browser testing and debugging
• Experienced in building applications that meet enterprise needs – secure, scalable, loosely coupled design
• Exceptional design, coding, and problem-solving skills, with a bias for architecting at scale.
• Experience using NPM, Web-Pack, Gulp.
• Familiarity with performance testing and optimization’s.
• Strong knowledge of computer science, algorithms, and design patterns
• Write robust modular front-end code using the latest technologies, test and optimize it to work for high performance and scale and deploy it to the UiPath cloud platform.
• Work with various horizontal teams such as Structure, Electrical, Mechanical, Accessibility, Legal, and Finance and also interact with other core teams across locations at UiPath
• Own the smooth running of your cloud service or docker service, and respond to live site issues.
• Strong oral and written communication, and other soft skills are critical to collaborating and engaging with teams

Responsibilities 

• Convert wireframes into rich interactive prototypes. 
• Work with backend development team to integrate front end code. 
• Understand business requirements and convert into functional specifications. 
• Participate in architecture and technical level discussions and takes initiative. 
• Passion for web design and eager to learn and implement the latest trends.
• A focus on delivering high-quality code through strong testing practices
• Working on Information architecture and Designing wireframes and prototypes.

Skills Required:

• 4+ years of commercial-grade web/front-end development experience.
• Strong experience in JavaScript, ideally ES6 or ES7, Node.js, building Single Page Web Applications with modern frameworks (Angular or AngularJS, React, Vue).
• 2+ years hands on experience with frameworks like react/relay/Redux/node.
• 2+ years with JS build tools like grunt,webpack,gulp etc.
• Knowledge in ES6, Webpack is a plus.
• Experience in creating web applications with delightful user experience.
• Experience working with REST APIs.
• Experience in TDD, Writing Clean & Readable code.
• Experience in Version control - Git.
• Awareness of cross-browser compatibility issues and client-side performance considerations 
• Experience in creating responsive pages and cross-browser support.
• Ability to clearly communicate thoughts and ideas by rapid prototyping.
• Debugging skills, familiar with debugging tools of all major browsers.

Nice to Have:

• Prior experience in Fintech Startups
• Knowledge of Node.js, Express js, AWS (EC2, S3, Elasticsearch)
• Knowledge and working experience with MongoDB, NOSQL

What You’ll Do

• Should be able to develop an application with vanilla Javascript without any frameworks.
• Maintain reusable code and improve code quality.
• Optimize application for maximum speed.
• Should take ownership and work closely with other teams. such as back-end.
• Make suggestions for better solutions to problems and keep abreast of the latest and emerging technologies.
• Be comfortable working throughout the lifespan of a project.

Who you are

• Should have minimum 5+ years of experience.
• Proficient understanding of web markup, including HTML5, CSS3 and vanilla JavaScript.
• Should have good knowledge on ES6.
• Understanding of CSS pre-processing platforms, such as LESS and SASS.
• Should be proficient any of the the frameworks  ReactJs, VueJs etc.
• Should have knowledge on Node Js.
• Should have hands on experience web component development.
• Good understanding of Responsive Web Designing, CSS media queries and Bootstrap library.
• Understanding of cross-browser compatibility issues and ways to work around them.
• Good understanding of asynchronous/Ajax request handling.
• Good understanding of OOJS.
• Knowledge of code versioning tools, such as GIT.
• Knowledge in writing UI test cases using any test framework.

Education

• Bachelor's  degree in Computer Science, Engineering or equivalent demonstrable experience. 

Benefits

• In addition to competitive salaries and benefits packages, Nisum India offers its employees some unique and fun extras:
• Continuous Learning - Year-round training sessions are offered as part of skill enhancement certifications sponsored by the company on an as need basis. We support our team to excel in their field.
• Parental Medical Insurance - Nisum believes our team is the heart of our business and we want to make sure to take care of the heart of theirs. We offer opt-in parental medical insurance in addition to our medical benefits.
• Activities -From the Nisum Premier League's cricket tournaments to hosted Hack-a-thon, Nisum employees can participate in a variety of team building activities such as skits, dances performance in addition to festival celebrations.
• Free Meals - Free snacks and dinner is provided on a daily basis, in addition to subsidized lunch.