Senior Software Developer (React + Python)

Position : Tech Lead – Fullstack Developer

Experience : 7 to 15 Years

Location : MG Road, Bengaluru (Hybrid – 3 Days in Office)

Notice Period : Immediate / Serving / 15 Days or Less

About the Opportunity :

We are hiring a Tech Lead – Fullstack Developer for a well-funded product startup building an enterprise-grade SaaS platform in the Cybersecurity domain.

The role involves designing and delivering scalable microservices and cloud-native applications in a high-performing, Agile engineering environment.

You'll work alongside industry veterans from billion-dollar digital firms, contributing to technical design, product architecture, and engineering best practices.

Mandatory Skills : Java, Spring Boot, ReactJS (or any modern JavaScript framework), RESTful APIs, PostgreSQL, Docker, Kubernetes, CI/CD, Hibernate/JPA, Multithreading, and Microservices architecture.

Role Highlights :

• Lead fullstack product development using Java (Spring Boot) and ReactJS (or similar frameworks).
• Design, develop, test, and deploy scalable microservices and RESTful APIs.
• Collaborate with Product, DevOps, and QA teams in a fast-paced Agile environment.
• Write modular, secure, and efficient code optimized for performance and maintainability.
• Mentor junior developers and influence architecture decisions across the team.
• Participate in all stages of the product lifecycle, from design to deployment.
• Create technical documentation, UML diagrams, and contribute to knowledge-sharing through blogs or whitepapers.

Key Skills Required :

1. Strong expertise in Java (mandatory) and Spring Boot.
2. Proficient in frontend development using ReactJS or similar frameworks.
3. Hands-on experience building and consuming RESTful APIs.
4. Solid knowledge of PostgreSQL, Hibernate/JPA, and transaction management.
5. Familiarity with Docker, Kubernetes, and cloud platforms (Azure/GCP).
6. Understanding of API Gateway, ACID properties, multithreading, and performance tuning.
7. Experience with CI/CD tools (Jenkins, GitHub Actions, GitLab CI) and Agile methodologies.
8. Strong debugging and profiling skills for performance bottlenecks.

Nice to Have :

• Experience with data integration tools (e.g., Pentaho, Apache NiFi).
• Exposure to the Healthcare or Cybersecurity domain.
• Familiarity with OpenAI APIs or real-time analytics tools.
• Willingness to contribute to internal documentation, blog posts, or whitepapers.

Perks & Benefits :

• Opportunity to build a product from scratch.
• Flat hierarchy and direct access to leadership.
• Strong focus on learning, mentorship, and technical innovation.
• Collaborative startup culture with long-term growth opportunities.

Interview Process :

1. Technical Round – Technical Assessment
2. Technical Interview – Core Development
3. Advanced Technical Interview – Design & Problem Solving
4. Final Round – CTO Discussion

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 Description :

- Strong understanding of the Ruby programming language and Rails framework

- Proficiency in Javascript including experience with React, Angular or Vue

- Database understanding (Postgres/MySQL)

- Previous experience maintaining production applications

- Focus on writing clear, maintainable, tested code.

Skills Required :

- Navigating and understanding a large codebase

- Experience with Git continuous integration and regular deployments

- Understanding and appreciation for UX and usability

- Excellent communication skills and diligent ability to contribute to the team by performing code reviews,

- Writing tests using Rspec and Capybara.

Job Description

We are looking for a skilled and ambitious Full-Stack Developer (React/React-Native, PHP, and NodeJs )to join our development team. In this role, you will be responsible for developing and implementing applications using React.js, NodeJS, PHP, and its libraries such as Redux, Redux-Saga, ExpressJs, Laravel. You will also be responsible for profiling and improving performance and documenting the codebase. To ensure success as a Full Stack developer, you should have in-depth knowledge of Javascript (ES6 or above), NodeJS, PHP 7.x, MySQL and its concepts, excellent coding skills, and a good understanding of progressive web applications.

Full Stack Developer Responsibilities:

• Reviewing application requirements and interface designs.
• Identifying web-based user interactions.
• Understand the past code and improve when needed.
• Develop components in a scalar way so, can be used again.
• Developing and implementing front-end + back-end architecture to support user interface concepts.
• Monitoring and improving application performance.
• Documenting application changes and developing updates.

Full Stack Developer Requirements:

• In-depth knowledge of Javascript, CSS, and HTML.
• In-depth knowledge of REACT libraries like Webpack, Redux, Redux-Saga and React Router.
• In-depth knowledge of NodeJs, ExpressJs, PHP, Laravel Framework
• Experience with User interface design and development.
• Experience with browser-based debugging and performance testing software
• Excellent troubleshooting skills.
• Build high-quality user interfaces from design mockups.
• Good project management skills and communication skills
• Collaborate with Product, Design, and other developers to understand requirements.
• Write tests to ensure high-grade code.
• Adhere to code style and code quality standards.
• Provide code review feedback to teammates.
• Good understanding of AWS infrastructure.

As a Senior Technical lead you will be a member of a software development team building innovative new features for the application. Lead the team as Senior Full Stack developer

Primary Job Responsibilities:

• Inherit a well-architected, clean, and robust codebase built with .NET Core 5.x, and JavaScript and Angular
• Evaluate and implement new libraries and components
• Ensure best practices are followed in the design and development of the application Contribute to and help manage our open-source libraries
• Strong knowledge of C# and .NET Core, JavaScript, Angular
• NoSQL databases (MongoDB)Real-time web applications (Web Sockets / SignalR)
• Containerization technologies (Docker, Kubernetes) Swagger /OpenAPI Initiative
• Strong knowledge of design patterns and practices
• Experience in non-Microsoft tech stacks as Node, Python, Angular and others are also crucial components of Source Control - GitHub Unit / Performance / Load Testing
• Experience with Continuous Integration - Jenkins/Travis/Circle/etc.
• Experience working in Agile Environments - JIRA/Slack
• Working knowledge of SAAS Architecture and Deployments - AWS/Google Cloud/etc.

• Think like a product owner
• Design and build new products and manage their delivery
• Drive culture, learning, and development of team members and of the larger org
• Mentor, motivate & ensure delivery from a small team
• Take ownership and get the job done
• Ensure the quality of deliverables

• 4-7 years of hands-on experience in the design and development of applications using NodeJs, ReactJs, MySQL, etc.
• Good architectural and design skills
• Strong coding, data structures, and algorithms
• An engineering degree preferably, from a top-tier school (or an equivalent experience)
• Proficient understanding of code versioning tools, such as Git/SVN
• Good understanding of asynchronous request handling, partial page updates, and AJAX
• Experience in Elastic Search/ Solr/ Amazon AWS
• Experience building sites to function cross-platform and cross-browser
• The ability to own end-to-end responsibility
• The role will give you an opportunity to work with a cross-functional team from Business, Product, and Design, and lead a team of 4-7 rockstar engineers.

• A team of aces, from top-tier schools and startups, to work with
• A fast-paced, data-driven, and fun work environment
• A huge appetite for new, disruptive, creative, and implementable ideas
• An open work culture

• Competitive salary
• A great working environment with an opportunity to work directly with the founders on very exciting real-life problems
• Opportunity to grow really fast.
• Opportunity to hire a team & mentor them.
• ESOPs