Senior Fullstack Engineer

About

Numispark is a France-based web and mobile development agency. We design, build and maintain custom digital products for clients across France and Europe — mobile applications, booking and marketplace platforms, e-commerce systems and business management tools.

We work with a modern JavaScript stack across mobile and web, and we manage our own production infrastructure. Our engineering culture is remote-first, asynchronous, and built around clear written communication and end-to-end ownership of what we ship.

The Role

We are looking for a Full Stack Developer to build and deliver production applications across mobile and web. You will work across the complete development lifecycle — designing APIs, building cross-platform mobile applications, developing web interfaces, and deploying and maintaining systems in production.

This is a hands-on engineering position with real ownership of features and release cycles. You will see your work reach live users on a short cycle, and you will have meaningful input into technical and architectural decisions.

Key Responsibilities

• Develop and maintain cross-platform mobile applications using React Native for Android and iOS
• Design and build RESTful APIs with Node.js and Express
• Model, query and optimise MongoDB databases for production workloads
• Build responsive web interfaces using React and Next.js
• Deploy and maintain applications on Linux servers using Docker, including CI/CD pipelines, reverse proxy configuration, SSL and database backup procedures
• Manage Play Store and App Store submissions, versioning and release cycles
• Maintain, extend and improve existing production applications
• Participate in code reviews and follow Git-based development workflows
• Communicate progress and technical decisions clearly in written English

Required Qualifications

Experience

• 3–6 years of professional software development experience
• Minimum 2 years of hands-on experience with React Native
• At least one React Native application published on the Play Store or App Store, with a clear description of your contribution

Frontend and Mobile

• React Native — navigation, native module integration, performance optimisation, platform-specific implementation
• React.js — hooks, component architecture, state management (Redux, Zustand or Context API)
• Next.js — SSR, SSG and App Router
• Strong JavaScript ES6+ fundamentals, including asynchronous programming patterns
• TypeScript in production environments
• Firebase — push notifications, analytics and crash reporting

Backend

• Node.js and Express — REST API design, middleware, error handling
• MongoDB — schema design, indexing, aggregation pipelines, Mongoose
• Authentication and authorisation — JWT, OAuth, role-based access control
• Real-time features — WebSockets and Socket.io
• Payment gateway integration — Stripe and Razorpay

Infrastructure and DevOps

• Proficiency on the Linux command line
• Docker — writing Dockerfiles, docker-compose, container troubleshooting
• Demonstrated experience deploying and maintaining applications on self-managed servers
• Self-hosted deployment platforms — Coolify, Dokku, CapRover or equivalent
• CI/CD pipelines with GitHub Actions
• Nginx reverse proxy configuration and SSL certificate management
• Git — branching strategies, pull requests, conflict resolution

Other

• Professional written and spoken English
• Availability for a daily overlap window of 2:00 PM – 7:00 PM IST to align with European business hours

Preferred Skills

The following are not required, but strengthen an application:

Mobile

• React Native New Architecture — Fabric and TurboModules
• Native module development in Swift or Kotlin
• Automated release pipelines with Fastlane or EAS
• Offline-first architecture and local persistence (MMKV, WatermelonDB, SQLite)
• End-to-end mobile testing with Detox or Maestro

Web and Frontend

• Tailwind CSS and modern component libraries (shadcn/ui, Radix)
• Animation and interaction work — Framer Motion, GSAP, Reanimated
• Web performance optimisation — Core Web Vitals, Lighthouse
• Technical SEO fundamentals for Next.js applications
• Accessibility standards (WCAG)

Backend and Data

• Redis for caching and session management
• Job queues and background workers — BullMQ, RabbitMQ
• GraphQL and Apollo
• PostgreSQL and Prisma
• MongoDB replica sets, Atlas administration, aggregation performance tuning
• Automated testing — Jest, Vitest, Supertest

Infrastructure

• Object storage integration (S3-compatible)
• Monitoring and observability — Sentry, Grafana, Uptime Kuma
• Infrastructure automation and shell scripting
• Container orchestration basics — Docker Swarm or Kubernetes
• Database backup, restore and migration procedures at scale

Other Platforms and Tooling

• Flutter
• Shopify theme and app development
• Odoo customisation
• Mapping and geospatial development — Leaflet, Mapbox, MongoDB geospatial queries
• Transactional email and deliverability (Brevo, SendGrid, Postmark)
• AI and LLM API integration in production products
• Working from Figma designs
• Agile delivery with Jira, Linear or similar
• Clear technical documentation writing
• Working knowledge of French

What We Offer

• Competitive compensation of ₹6,00,000 – ₹8,00,000 CTC per annum, based on demonstrated experience
• Fully remote position, open to candidates across India
• Flexible working hours outside the daily overlap window
• International project exposure, working on products for European clients
• End-to-end ownership of features, from design through to production release
• Modern technology stack across mobile, web and infrastructure
• Scope to influence architecture and technical direction
• Continuous professional growth across the full engineering stack

Selection Process

1. Application review
2. Introductory call — 30 minutes
3. Technical assignment — 4 to 6 hours, compensated
4. Live technical discussion — 90 minutes, practical and collaborative
5. Offer

Typical timeline from application to offer: two weeks.

We are seeking a mature, proactive, and highly capable Senior Java Full Stack Engineer with 4 – 6+ years of mid/senior profile in Java, Full Stack, React, Cloud Services. The ideal candidate can handle multiple challenges independently, think smartly, and build scalable end-to-end applications while also owning architecture and deployment. Passionate about innovation, problem-solving and optimizing system performance.

Must Have Skills

• Java, Spring Boot, Hibernate, REST API, Gradle, Redis
• React JS, Node JS, Vue JS, or TypeScript
• Cloud Services (AWS, VM, Storage, Auth and Auth, Functions, and Deployments) 
• Microservices, Serverless Architecture
• Databases: MySQL, PostgreSQL, MongoDB
• Docker, Container orchestration (Kubernetes)
• API Development & Integration
• Bitbucket or Git-based version control
• Agile/Kanban working model

Good to Have Skills

• Familiarity with AI-powered coding assistants such as GitHub Copilot, Cursor AI, or Lovable AI.
• Basic understanding of Generative AI concepts and prompt engineering.
• Python (Fast API, Django REST Framework, Flask), PY Spark, Pandas
• API Testing Tools (Postman)
• CI/CD Pipelines
• Advanced Cloud Networking & Security
• Automation Testing (Playwright, Selenium) 
• Generative AI (LLMs, RAG Framework, Vector DB, AI Chatbots, Agentic AI)

Preferred Personal Attributes

• Highly proactive and self-driven
• Smart problem solver with strong analytical ability
• Ability to work independently in ambiguous and complex scenarios
• Strong communication & stakeholder management skills
• Ownership mindset and willingness to handle multiple challenges at once

Key Responsibilities

Full Stack Development

• Build and maintain production-grade applications using Java, Microservices, Python, and React/Next.js.
• Develop reusable frontend components and optimized backend services/microservices.
• Ensure clean architecture, maintainability, and code quality.
• Own development across the lifecycle—design, build, testing, deployment.
• Build AI chatbots, automation agents, and intelligent Assistants.
• Apply prompt engineering, fine-tuning, and model evaluation best practices.
• Deploy, manage, and monitor cloud workloads on AWS/Azure/GCP.
• Design and implement serverless architectures, microservices, and event-driven flows.
• Use Docker, CI/CD, and best DevOps practices.
• Ensure scalability, security, cost optimization, and reliability.

Collaboration & Leadership

• Comfortably handle ambiguity, break down problems, and deliver with ownership.
• Lead technical initiatives and mentor junior team members.
• Work closely with cross-functional teams in Agile/Kanban environments.

Job Title: Tech Lead – Full Stack

Location: MG Road, Bangalore

Work Mode: Hybrid

Interview Mode: Virtual

Experience Required: 7–12 Years

Role Overview

We are looking for a Tech Lead – Full Stack with 7 to 12 years of experience in developing scalable SaaS products using Java, Spring Boot, and JavaScript frameworks. The ideal candidate has hands-on experience with microservices architecture, performance optimization, and cloud-native development, and is passionate about mentoring teams and driving engineering best practices.

Key Skills & Expertise

• Proficient in building scalable SaaS products with a focus on microservices architecture.
• Technologies: Java (Mandatory), Spring Boot, ReactJS or any other JavaScript framework.
• Strong experience in designing RESTful APIs and using mocking frameworks.
• Skilled in profiling services and debugging performance issues.
• Knowledge of Docker and Kubernetes for containerization.
• Familiar with data integration tools such as Pentaho Kettle or Apache Nifi.
• Ability to influence technical decision-making, with a strong focus on automation and security best practices.

What You Will Do

• Design, implement, test, and deploy both front-end and back-end components of the product.
• Build and deliver highly scalable services using Spring Boot.
• Develop frameworks and accelerators to speed up development.
• Establish and enforce engineering best practices.
• Create and review design artifacts using UML for team-wide implementation.
• Mentor and guide product engineers within the team.
• Ensure on-time delivery of user stories planned for sprints.
• Engage in all stages of the product development lifecycle – from planning and design to implementation and testing in multi-cloud environments.
• Deliver robust, quality-focused technical solutions to business problems.
• Work alongside a talented team solving complex technical challenges in building large-scale SaaS products.
• Contribute from the ground up to the architecture and modularization of the product for long-term scalability and maintainability.
• Share knowledge and expertise by writing blogs, articles, and whitepapers.

 Technical Requirements

• Design and implement microservices architectures using Java and Spring Boot.
• Create, manage, and secure RESTful APIs.
• Collaborate with cross-functional teams in an Agile setting to ensure high-quality delivery.
• Mentor and support junior developers on the team.
• Experience with cloud platforms such as Azure or GCP, and orchestration tools like Docker and Kubernetes.
• Strong database skills in PostgreSQL.
• Exposure to:
• API Gateway
• Hibernate & JPA
• Transaction Management
• ACID Properties
• Multithreading & Context Switching
• Healthcare domain experience is a plus.

Team Lead Full Stack Developer responsible for managing back-end services and the interchange of data between the server and the users.

Your primary focus will be the development of all server side logic, definition and maintenance of the central database, and ensuring high performance and responsiveness to requests from the front-end. You will also be responsible for integrating the frontend elements built by your co-workers into the application. Therefore, a basic understanding of frontend technologies is necessary as well.

We are looking to recruit a candidate for a role that will require:

• Create and consume restful APIs
• Design, develop, and maintain internal and external applications
• Build efficient, testable, and reusable modules
• Write high quality, structured application/interface code and documentation
• Identify solutions through research and collaboration that resolves the root of problems as they arise
• Define functional and technical requirements for application software to develop skills and knowledge
• Troubleshoot, test and maintain the core product software and databases to ensure strong optimization and functionality
• Contribute in all phases of the development lifecycle

Requirement

∙ Proficient in Node.JS and ReactJS development stack

∙ 5+ years’ experience designing, querying, and updating databases in MySQL/nosql

∙ Basic understanding of web technologies including HTML, CSS, JavaScript, AJAX etc.

∙ Passion for best design and coding practices and a desire to develop new bold ideas

∙ Good to have knowledge of AWS, Redis, ElasticSearch

Education: Min. Graduate in related discipline

Work experience: 5 years relevant experience

MERN Stack Developer

Location: Surat, Gujarat (No WFH )

Job Summary:

We are looking for a Full Stack Developer (MERN) with hands-on experience in building highly scalable, performance-driven applications. The ideal candidate should have a deep understanding of both front-end and back-end development, microservices, and database optimization for large-scale systems. You will be responsible for designing, developing, and maintaining applications that can handle high concurrency (1,000+ active users) while ensuring performance, reliability, and scalability.

This role involves working closely with cross-functional teams — including product managers, designers, and DevOps engineers — to deliver cutting-edge, enterprise-grade solutions.

Roles & Responsibilities:

• Design and develop scalable and distributed web applications using the MERN stack (MongoDB, Express.js, React/Next.js, Node.js).
• Build and optimize RESTful APIs for high-performance, concurrent environments.
• Architect and manage MongoDB databases, ensuring high availability, efficient query performance, and scalability.
• Implement queueing systems (e.g., BullMQ, RabbitMQ, Kafka, or Redis Queues) for background jobs and asynchronous processing.
• Optimize server and client performance to support real-time data updates and high concurrent user loads.
• Collaborate with DevOps to improve deployment pipelines, containerization (Docker), and cloud scalability.
• Conduct thorough testing, profiling, and debugging to identify performance bottlenecks and optimize both code and infrastructure.
• Participate in code reviews, architecture discussions, and sprint planning to ensure technical excellence and scalability across all layers.

Qualification / Requirements:

• Bachelor’s degree in Computer Science, Engineering, or related field (or equivalent experience).
• 1 + years of hands-on experience in full-stack development using the MERN stack.
• Proven experience working on applications supporting 1,000+ concurrent users or large-scale distributed systems.
• Strong expertise in:
• Node.js (asynchronous programming, clustering, performance optimization)
• Next.js & React.js (SSR, CSR, and dynamic rendering)
• MongoDB (aggregation pipelines, indexing, schema design for scalability)
• Practical experience with message queues (BullMQ, RabbitMQ, Kafka, or Redis Streams).
• Familiarity with caching mechanisms (Redis, Memcached) to optimize performance.
• Experience with Docker and microservices-based architectures is a plus.
• Good understanding of API design, authentication mechanisms (JWT, OAuth), and security best practices.
• Experience working in Agile environments and using Git-based version control.

Nice to Have:

• Exposure to serverless computing (AWS Lambda).
• Experience with monitoring tools (New Relic, Datadog, ELK Stack).
• Knowledge of CI/CD pipelines and automated deployment workflows.
• Experience in real-time communication (WebSockets, Socket.io).

We are looking for ambitious hands-on coders who love building web based applications from the ground up and have a special affection for all things JavaScript.

Responsibilities:

• Develop robust, web-based applications interacting with database filesystems and APIs
• Obsess about code quality and readability
• Remain updated on new and evolving client-side technologies, their application to our functionality or architecture goals
• Work closely in a multi-disciplinary structure to deliver world class solutions across web, mobile, and tablets
• Identify and establish best practices and frameworks keeping in mind parameters of performance, responsiveness, security, maintainability, extensibility, and reuse

Must have:

• At least 3 years of experience in developing web based applications with experience in Node.Js
• Skilled at Object Oriented JavaScript and having a working knowledge of at least one of the following MVC Frameworks (Angular, Backbone, Ember, React etc.).
• Knowledge of database, preferably some NoSQL DB like Mongo.
• Familiar with Git version control system