Full Stack Developer

Fountane Archipelago  ·  Island Role

A Little Bit About the Role

We are looking for a Senior Product Engineer (L3) who thrives in complexity. Most engineers build on blank canvases — you build on someone else’s mess and leave it better than you found it.

The majority of your work at L3 will be on existing, live codebases — disorganised, partially documented, built by multiple teams over multiple years. Your job is to enter those systems, understand them before touching them, extend and clean them without breaking what works, and progressively bring them up to a standard where AI tooling can accelerate further development. This is the core of what L3 does at Fountane. If you have only built greenfield projects, this role will be hard.

You are expected to be genuinely full stack: comfortable owning web applications and mobile apps, the frontend, backend, database, state management, and API integration layer — without needing to hand off to a specialist.

You will work closely with the Concept Engineer on your Island — translating their prototypes into production architecture, raising technical blockers early, and keeping the sprint honest. You will also review code, mentor junior engineers, respond to production incidents, and contribute to the network’s shared knowledge base.

All of this is done primarily with Cursor and Claude as your execution and reasoning tools. AI-assisted engineering is not a feature of this role — it is the method.

AI-First Engineering Expectation

Cursor and Claude are your primary tools — not supplements. Engineers at L3 who are not using AI at the codebase level are not operating at this level.

At L3, AI-assisted engineering means:

• Loading full codebase context into Cursor before writing a single line — understanding the system before touching it.
• Writing scoped, precise refactor prompts that isolate changes to one concern at a time.
• Using Cursor to generate tests that document existing behaviour before any restructuring begins.
• Using Claude for architecture reasoning, decision documentation, and translating CE briefs into structured technical plans.
• Producing inline documentation and decision records as part of the AI-assisted workflow — not as an afterthought.
• Sharing effective prompt patterns and Cursor discoveries with the broader Fountane network — kept to yourself, they are a missed contribution.

Key Responsibilities

Legacy Codebase Refactoring & the Cleaning Phase

This is the primary L3 engagement type at Fountane. You will be handed existing, partially documented codebases — built by previous teams, often without tests, with inconsistent patterns — and your job is to refactor them into a clean, AI-promptable state without losing existing functionality. You use Cursor’s codebase context window to navigate safely, write characterisation tests before touching anything, and make changes in small, reviewable increments. The standard is: every module you leave should be easier to extend by AI tooling than when you found it.

Full Stack Development — Web & Mobile

Build and own the full application layer: React / Next.js web frontends, React Native or Flutter mobile apps, Node.js / Python backends, and relational and non-relational databases. You should be able to pick up web or mobile on any engagement without needing a handoff. Schema design, data modelling, and state architecture are yours to own — including diagnosing and fixing broken or leaking state in existing frontends.

Third-Party API Integrations

Integrate complex third-party services — payments (Stripe), communications (Twilio), auth (Auth0), and others — reliably and without creating brittle dependencies. Own the integration layer end to end: error handling, retries, failure modes, and documentation. If a third-party integration is flaky in production, that is your problem to own.

CE Collaboration & Sprint Integrity

Work directly with the Concept Engineer to translate prototypes into buildable technical plans. Review CE briefs before the sprint starts — if the scope is technically unrealistic, the time to say so is before work begins, not on demo day. Raise blockers against acceptance criteria proactively. You are the technical check on what the CE promises the client.

Security Awareness

Write code that does not require the Lead to security-audit every line. This means: input validation by default, no hardcoded secrets, correct auth scoping, safe handling of user data, and awareness of common vulnerabilities (injection, broken auth, insecure direct object references) in the context of the stacks you work in. You are not the security architect — the Lead owns that — but you are expected to produce code that does not introduce obvious vulnerabilities.

Production Incident Response

When something breaks in production, you are on it. Diagnose the issue, apply a safe fix or rollback, document what happened and why, and hand a clear summary to the Lead for the client post-mortem. Speed matters, but a bad fix that causes a second incident is worse than a slow fix that is correct. Response expectation: acknowledged within 1 hour, resolved or escalated with a clear status within 4 hours.

Codebase Navigation & Safe Refactoring

On all engagements — not just Cleaning Phase work — keep changes small, focused, and reviewable. One type of change per commit. Write tests that document existing behaviour before restructuring. Leave every module easier to understand than when you found it.

Code Review

Review pull requests from L1 and L2 engineers with specific, actionable feedback — not rubber-stamp approvals. A good code review at L3 leaves the author understanding what to do differently next time, not just what to fix now. Review weekly; do not let PRs age.

Mentoring

Review junior engineers’ code weekly with specific, useful feedback — this is distinct from quality-gate code review. The goal here is teaching, not gatekeeping. Run monthly pairing sessions to help them grow. The measure of good mentoring is whether they are becoming more capable and less dependent on you over time.

Documentation

Write short decision records when you make significant technical choices. Leave every module you touch easier to understand than when you found it. Treat documentation as part of the engineering work, not a separate task you do at the end.

Qualifications

• 5+ years of experience as a software engineer, with a strong track record on real production codebases you did not build from scratch — incomplete documentation, inconsistent patterns, other people’s decisions. If your experience is primarily greenfield, this role will be a difficult fit.
• Genuinely full stack across web and mobile: proficient in React / Next.js and at least one of React Native or Flutter, Node.js or Python on the backend, and comfortable with both relational and non-relational databases including schema design.
• Hands-on, daily Cursor and Claude usage at the codebase level. You should be able to describe concretely how you use AI in your engineering workflow — not in general terms.
• Experience integrating complex third-party APIs in production environments — not just following a quickstart guide. You should be able to describe an integration that failed in production and what you did about it.
• Solid security awareness for the stacks you work in: input validation, auth scoping, safe data handling. You do not need a security specialism, but you should not be writing code that introduces obvious vulnerabilities.
• Has conducted meaningful code reviews that improved the code and the author, not just approved the PR.
• Has coached or mentored junior engineers before, and done it well.
• Comfortable with production incident response — diagnosing issues under pressure, applying safe fixes, and communicating clearly to a Lead or client about what happened.
• Treats documentation as part of the job, not an afterthought.
• Bachelor’s or Master’s in Computer Science or a related field, or equivalent experience.

About Fountane

Fountane is a technology ventures lab - one part product studio, one part startup engine. We build high-quality software and AI products for clients ranging from fast-moving startups to large enterprises, and we co-build and invest in new companies when we see the right opportunity.

Founded in 2017 and headquartered in Minneapolis, we have grown to 60+ people across four continents and were recognised as one of America’s fastest-growing companies, ranking No. 699 on the Inc. 5000 with 595% three-year growth.

We are radically open-minded, serious about craft, and direct about expectations. If you want to do meaningful work without politics, this is the place.

Job Title: Full Stack Developer (Node.js + React.js)

📍 Location: Gurgaon (On-site)

🕒 Experience: 5+ Years

🕒 Working Days: 5 Days(Mon-fri)

Job Summary:

We are hiring a passionate and experienced Full Stack Developer proficient in Node.js and React.js for our client. The ideal candidate should have solid experience in designing scalable systems, writing optimized code, implementing role-based access control, handling task prioritization, and building robust web applications.

Key Responsibilities:

• Design scalable user management systems with role-based access and authentication.
• Develop backend services and REST APIs using Node.js.
• Build dynamic and optimized front-end applications using React.js and Redux.
• Handle async operations, task queues, and implement retry and prioritization logic.
• Optimize React components for performance using hooks and memoization.
• Ensure secure and scalable system design with proper error handling and authorization flows.
• Apply JavaScript concepts like closures, event loop, and async patterns in real-world scenarios.
• Collaborate with DevOps for basic CI/CD and deployment processes.

Mandatory Technical Skills:

• Frontend: React.js, Redux, JavaScript (ES6+)
• Backend: Node.js, Express.js
• Authentication & Authorization: JWT, OAuth2, Role-Based Access Control (RBAC)
• Task Management: Async/Await, Promises, Retry Mechanisms
• Database: MongoDB or PostgreSQL
• Version Control: Git

Soft Skills:

• Strong problem-solving and system design skills
• Ability to work independently and in a collaborative team
• Clear communication of technical ideas
• Ownership of tasks and components end-to-end

Focus Areas:

• System Design (User Management, Fault Tolerance, Load Distribution)
• JavaScript Core Concepts (Closures, Scope, Event Loop)
• React Optimization & Hooks
• Node.js Architecture & Async Programming
• Task Prioritization and Retry Logic

* Good knowledge of Node.js/ NextJS, Express.js, React and MongoDB

* Need a clear understanding of JavaScript and Typescript.

* Excellent grasp of data structures and designing and developing REST APIs.

* Good skills of either RDBMS (e.g. MySQL or PostgreSQL) or NoSQL (MongoDB or equivalent).

* Must have at least 3 years’ experience in MERN Stack development.

* Experience in developing responsive web applications.

* Good communication skills.

* Sound understanding of Agile and Scrum methodologies and ability to participate in local and remote Sprints.

* Good grasp of UI / UX concepts.

* Should have experience in using Git and VSCode.

* Knowledge of AWS, Azure, CI / CD, Gitflow, shell scripting will be considered positively.

Full Time @ Anywhere in India

3+ years

• Taking an active role in architecting the solutions we build
• Designing and implementing web applications using JavaScript and its frameworks (i.a. React, Vue, Angular), HTML5 and CSS3
• Working closely with the dispersed development team, client, and project manager in SCRUM methodology
• Ensuring that programming practices and code quality are respected
• Supporting other engineers with your expertise when needed (knowledge sharing)
• Leading your colleagues’ growth and development

• 2+ years of experience with JavaScript (good knowledge of ES2016; newer versions and TS 3+ are a plus)
• Experience in developing web applications using Angular2+ and another modern framework
• Being comfortable HTML5 and CSS3
• Experience with version control systems, preferably Git
• Demonstrated tech leadership in a medium-sized team, and the ability to design a really complex system
• Eagerness to learn and constantly improve yourself
• Being a team player focused on getting things done

• Experience with React.js and Node
• Experience with AWS or GCP infrastructure
• Curiosity about new languages, libraries, frameworks
• Contributions to open-source projects

• Passionate about making an impact
• Self-driven & eager to learn new technologies
• Intellectually curious, interested to build complex systems
• Thrive in a highly independent, remote-first environment
• Keen to work with a globally diverse team

• Hybrid Work Option - Step out when you “want to” not when you “have to”
• Work from the comfort of your home or work at the office
• Support for setting up Home-office
• Flexible Work Hours -Work-life balance becomes a lot easier to maintain with the flexibility to plan your work hours 
• Flexible Leave policies
• Life needs a break - casual, parental, sick, or just random. To help you enjoy your leaves without guilt or excuses, we have a ‘no approval needed’ policy
• Health and Wellness - Constant encouragement to stay fit
• We encourage and support our team members to participate in memberships that promote team member health (physical, emotional, and psychological) and fitness
• Reimbursements for medical support
• Career ladder: the freedom to design your own path
• Well defined career ladders to grow, assess and explore your professional journey
• Learning opportunities
• In house learning platforms to partner with you in your growth story
• Wide range of courses and certifications

•  Developing both frontend and backend of application using technologies like Java,   Angular, JavaScript, HTML5.
•  Designing user interactions on web pages.
•  Designing and Developing back end API's and databases.
•  Meeting both technical and customer’s needs.
•  Seeing through a project from conception to finished product.
•  Take complete ownership of the project and deliver with good quality.
•  Staying abreast of developments in web applications and programming languages.

• Relevant experience of 8+ yrs
• Strong communication, organizational skills. Good in Agile, Scrum, Dev-Ops practices.
• Proficiency with fundamental front end languages such as HTML5, CSS and JavaScript.
• Familiarity with JavaScript frameworks such as Angular, React and Amber.
• Proficiency in Java, Springboot, Microservices
• Familiarity with database technology such as PostgreSQL, MySQL, Oracle and MongoDB.
• Good in writing quality code and Unit Tests. Good knowledge of DevOps practices.
• Excellent verbal communication skills.
• Good problem solving skills

We need multiple MEAN stack developers. As a full stack developer, you will be producing scalable software solutions and will be involved in the full software development life cycle, from conception to deployment. You should be comfortable around both front-end and back-end coding languages, development frameworks and third-party libraries. This isn't just another CRUD application. Your challenge will be to deliver a highly-available service on top of a dynamic collection of third-party data sources . Explore the limits of your own resourcefulness by designing human and automated systems that deliver true reliability in an otherwise unpredictable environment.

Tech-Stack: Angular, Node.js, JavaScript, and MongoDB

How You Will Contribute

• Work with the development team to ideate software solutions
• Working through the application development lifecycle to launch
• Conceptualizing, creating and building applications alongside taking designer wireframes and magically turning them into effective code
• Designing user-based interactions through effective front-end architecture
• Develop and manage well-functioning databases and back end applications
• Write effective and scalable APIs
• Leading and developing best practices for Full Stack Developer team
• Developing and designing RESTful services and APIs
• Determining application responsiveness for consumers
• Ensuring company mandate is effectively addressed in technical and developmental aspects
• Create security and data protection settings
• Write technical documentation
• Keeping current with industry trends and developments that can be applied to company needs

Technical Expertise That We Believe Will Make You Successful In This Role

• Min 1 year of experience as a MEAN Stack Developer
• Fluency in CSS, JavaScript and HTML
• Understanding of CSS preprocessors including Sass
• Strong knowledge of building effective APIs in Node.js (Express)
• Proficiency in writing effective Angular components.
• Experience working with MongoDB, Redis and AWS
• Good knowledge of data structures, system design and algorithms
• Bachelor/Master degree in Computer Science
• Soft-Skills That Will Come Handy
• Having a knack for visual design and utility
• Excellent written and verbal communication skills
• Strong attention to detail
• Head for problem-solving
• Having a flexible working style
• Being a team player
• Comfortable with working unsupervised

What We Need

- Solid industry experience

- Hands-on Experience with MEAN((MongoDB, Express.js, AngularJS, and Node.js) full-stack

- Experience in creating front end applications using HTML5, Angular 6x+, LESS/SASS, Bootstrap/Angular Material

- Having decent knowledge in Typescript

- Having experience in building a responsive web design

- Experience with MongoDB and good knowledge in database concepts

- Experience with web frameworks like ExpressJS

- Developing secure Node.js endpoints using Passport, JWT, OAuth, and related technologies.

- Knowledge in Restful API Design

- Experience with Version control systems like GIT and knowledge in GIT branching is necessary.

- Strong object-oriented knowledge in any platform is a plus

Good to Have

- Open Source Contributors (esp. JavaScript to be evident from GitHub)

- Notice period to be less than 30 days

What you need to have:

• Must have strong exposure working on Java Script 
  
• Proficient in Javascript frameworks (Vue Js / React Js) is a must
• Strong understanding of REST APIs
• Have experience with common front-end development tools such as Babel, Webpack, NPM is a definite advantage
• Good understanding of asynchronous request handling, partial page updates, and AJAX
• Proficient understanding of code versioning tools, such as GitHub
• Good to have working experience on CSS pre-processor either LESS or SASS
• Good understanding of BEM (Block, Element, Modifier) methodology