Web Developer

MERN Stack Developer – Job Description

Position: MERN Stack Developer

Experience: 3 - 9 Years

Location: remote

Employment Type: Full-Time

Job Summary

We are looking for a skilled MERN Stack Developer to join our development team. The candidate will be responsible for designing, developing, testing, and maintaining scalable web applications using MongoDB, Express.js, React.js, and Node.js.

Key Responsibilities

• Develop and maintain web applications using the MERN stack.
• Build responsive and user-friendly interfaces using React.js.
• Develop scalable and secure backend APIs using Node.js and Express.js.
• Design and manage databases using MongoDB.
• Integrate third-party APIs and services.
• Write clean, reusable, and maintainable code.
• Troubleshoot, debug, and optimize application performance.
• Collaborate with UI/UX designers, developers, QA, and project managers.
• Participate in code reviews and follow development best practices.
• Ensure applications are secure, scalable, and performance-oriented.

Required Skills

• Strong knowledge of React.js, Node.js, Express.js, and MongoDB.
• Good understanding of JavaScript/ES6+.
• Experience with RESTful APIs.
• Knowledge of HTML5, CSS3, and responsive design.
• Familiarity with Git/GitHub.
• Understanding of authentication and authorization mechanisms such as JWT/OAuth.
• Good understanding of database concepts and query optimization.
• Strong problem-solving and communication skills.

Good to Have

• TypeScript experience.
• Redux/React Query.
• Experience with AWS or other cloud platforms.
• Knowledge of Docker and CI/CD.
• Experience with Agile/Scrum methodology.

Education

Bachelor's degree in Computer Science, IT, Engineering, or a related field is preferred.

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.

We are a dynamic and innovative technology company dedicated to delivering cutting-edge solutions that empower businesses and individuals. As we continue to grow and expand our offerings, we are seeking a coding fanatic, who is interested in working on and learning new technologies. 

Position - Backend developer 

Job type - Freelance or on contract 

Location - Remote 

Roles and Responsibilities:

• Plan,create and test REST APIs for back-end services such as authentication and authorization.
• Deploy and maintain backend systems on the cloud.
• Research and develop solutions for real life business problems.
• Creating and maintaining our apps' essential business logic, providing correct data processing and flawless user experiences.
• Database design, implementation, and management, including schema design, query optimisation and data integrity.
• Participating in code reviews, providing constructive input, and ensuring that code quality standards are met.
• Keep abreast of industry developments and best practices to bring new solutions to our initiatives.

Required skills and experience - 

Must have skills : -

• Bachelor’s degree in computer programming, computer science, or a related field.
• 3 + years of experience in backend development.
• Proficient in Python,Mongodb,postgres/sql,Django and Flask
• Knowledge on nginx.
• C++/C +Cython for creating python modules
• Knowledge on Redis
• Familiarity with using AI provider apis and prompt engineering
• Experience in working with linux based instances on the cloud.
• Strong problem solving and verbal and written communication skills.
• Ability to work independently or with a group.

Good to have skills :- 

• Experience in node.js and Java 
• AWS and Google cloud knowledge.

Around 4 years of experience in creating and implementing Web-based products using PHP,

MySQL, Ajax, and JavaScript.

Ability to work in an Agile, fast-paced environment, and learn rapidly.

Bachelor degree in computer science, computer engineering or similar.

Expert in HTML, CSS, JavaScript, JQuery, JSON.

Experience in any PHP framework Laravel, CodeIgniter or Zend.

Writing clean, readable, and easily maintainable code.

Must have knowledge of project/task management tools like Jira,

Familiarity with Version Control Tortoise Bitbucket, Git etc.

Understanding of UI, cross-browser compatibility and web standards.

Good English communication skills, written and spoken.

Able to work with minimum supervision as well as perform under pressure and meet

Deadlines.

We are looking for skilled Senior Full-Stack developers who can architect and develop large-scale enterprise applications using React.js for front-end and Node.js for API's.

Responsibilities :

●      Review application requirements and interface designs.

●      Identifying web-based user interactions.

●      Developing and implementing highly responsive user interface components using React concepts.

●      Writing application interface codes using Javascript following React.js workflows.

●      Understand proposed features and quickly design and build scalable API and SQL schema & queries.

●      Proactively analyze website performance and implement solutions for improvement.

●      Collaborate with architects, developers, business analysts, and QA analysts to design, develop, and test applications.

●      Documenting application changes and developing updates.

●      Collaborate with other team members.

Requirements :

●      Proven work experience as MERN developer (5+yrs)

●      3+ years of experience building complex web applications.

●      Solid work experience using component-based development on the client-side.

●      3+ years of experience coding robust and secure Rest API's in Node.js, JSON, XML.

●      Experience coding in JavaScript, HTML, CSS.

●      Experience in integrating systems using Rest APIs and single sign-on.

●      Experience with continuous integration / continuous deployment using AWS CodePipeline and CloudFormation templates.

●      Experience with AWS infrastructure (API Gateway, S3, Lambda, Aurora, EC2).

●      Experience with Google Analytics integration.

●      Deep knowledge to create standards-compliant, cross-browser, mobile compatible front-end code with responsive design.

●      Deep knowledge of server-side and front-end performance optimization.

●      Strong design skills are a huge plus.

●      Should be a self-starter who is excited to solve many technical challenges relentlessly.

●      Must have excellent written and verbal communication skills.

About https://validateme.online/">ValidateMe Online:

The ValidateMe Online platform enables the users to securely store and share their employment, educational and personal documents. ValidateMe uses blockchain technology to maintain the privacy of the documents and ensures that only the owners have the authority to view or share the documents. It acts as a common platform for users and organizations, educational institutes and universities to complete the background process seamlessly and quickly.

What You Will Do

• Lead the delivery of high quality, innovative, flexible, and scalable technical solutions that meet business requirements
• Perform hands-on development and provide thoughtful code reviews
• Mentor and lead development team members to continuously improve quality and productivity to achieve business results
• Design, develop, test and support applications and services using React, NodeJS, mongoDB, blockchain and others.
• Engage in requirements analysis and product engineering discussions, leading to delivery of high-quality user stories and acceptance criteria.
• Conduct Proof of Concepts for testing business ideas.
• Recommend ways to improve reliability, maintenance, efficiency, and quality.
• Follow SCRUM Agile Development methodology
  
  

What You Will Need

• 6+ years of relevant experience
• Advanced knowledge of software development methodology, techniques & standards.
• Strong understanding of software design concepts, patterns, tools and best practices.
• Must have full stack experience using NodeJS, React and NoSQL Databases.
• Must have worked on at least one cloud platform.
• Should have built and used a REST API.
• Experience with mongoDB is a plus.
• Experience with blockchain technology is a plus.
• Background building container using docker and deploying using Kubernetes is a plus.
  
  

Who You Are?

• One with excellent communication and prioritization skills.
• Owns success – Takes responsibility for the successful delivery of the solutions.
• Strong desire to improve upon one’s skills in software development, frameworks and technologies

What We Offer

• Limitless growth and learning opportunities.
• A collaborative and positive culture — Your team will be as smart and driven as you.
• Outstanding compensation, including attractive Employee Stock Options.
• A chance to make an impact — Your work will contribute directly to our strategy.