Node.js Developer

Senior Backend Engineer

Node.js, System Design & Production Platforms

📍 Mumbai (On-site) | Full-time | 5+ years

About the Role:

Unico Connect is an AI-first technology partner that builds custom mobile, web, and AI products for clients across multiple geographies.

We are hiring a Senior Backend Engineer to own the backend architecture of a complex production AI platform on a dedicated client engagement: API design and data modelling, multi-tenancy, orchestration of long-running agent workloads, and the services that manage user projects and generated output.

We are open to full stack engineers whose primary strength and interest is backend. If you have shipped full stack work but the backend is where you do your deepest engineering, you are a fit for this role.

The mandatory requirement for this role is hands-on production experience as a senior backend engineer building complex, scalable systems in Node.js, with end-to-end ownership of architecture, data, and operations on at least one live platform.

The role is hands-on and architectural.

Expect to design system architecture, lead a small group of backend engineers, build the hardest parts yourself, set engineering standards, and partner closely with frontend, AI, and DevOps engineers.

A typical week includes an architecture decision on a new service, hands-on implementation of a critical path, a code review with mid-level engineers, and a working session with the AI engineer on an integration contract.

Responsibilities:

System Architecture

Own the backend architecture across engagements.

Make and document decisions on service boundaries, data models, API contracts, deployment topology, and trade-offs.

Hands-on Backend Delivery

Lead by example on complex modules, performance-critical paths, and high-risk areas using Node.js (Express, NestJS, Fastify) with TypeScript.

Pick up Python (FastAPI) where engagements require it.

Database Design and Performance

Drive PostgreSQL schema design, indexing, query optimisation, migrations, and capacity planning.

Set the data-modelling standard across the pod.

Caching, Queues, and Workflows

Design caching (Redis), event-driven patterns (Kafka, RabbitMQ, SQS, NATS), and long-running workflow orchestration (Temporal, BullMQ, Celery, or equivalent).

Handle retries, idempotency, and failure recovery.

Multi-Tenancy and Platform Patterns

Design and implement multi-tenant data isolation, RBAC, audit logging, and resource quotas appropriate to enterprise-grade products.

API and Integration Design

Set the standard for REST, GraphQL, and gRPC contracts.

Drive versioning, authentication (OAuth, JWT, SSO), security by default, and developer ergonomics.

Observability and Operations

Instrument services with OpenTelemetry, Prometheus, and Grafana.

Define SLOs, lead incident response, and write postmortems.

Code Quality and Mentorship

Run code reviews, define conventions, mentor mid-level engineers, and raise the engineering bar.

AI-Assisted Engineering Discipline

Use Claude, Cursor, and similar tools day to day.

Set the team standard for prompts, patterns, AI-assisted review, and validation of AI-generated backend code.

Client Engagement

Represent Unico Connect in technical conversations with customers.

Defend architectural decisions, communicate trade-offs, and manage scope.

Requirements:

Hands-on Production Experience as a Senior or Lead Backend Engineer in Node.js (Mandatory)

Must have personally built and shipped complex production systems in Node.js, owning architecture, data, and operations on at least one live engagement.

Full stack engineers whose deepest work is on the backend qualify.

POCs and internal tools alone do not qualify.

5+ Years of Professional Backend Engineering Experience

With at least 1 to 2 years in a senior or lead role with direct responsibility for technical decisions and team output.

Deep Node.js and TypeScript Proficiency

Strong with Express, NestJS, or Fastify.

Comfort with async patterns, streams, worker threads, and performance profiling.

Python as a Strong Plus

Hands-on production experience with FastAPI, Django, or Flask is a meaningful advantage.

Willingness and demonstrated ability to pick up Python as engagements demand is required.

PostgreSQL Depth

Schema design, normalisation, indexing, query performance, migrations, and at least one production system where you owned the data model end to end.

Caching and Event-Driven Architecture

Hands-on with Redis (or equivalent) and message queues or event-driven patterns (RabbitMQ, SQS, Kafka, NATS).

AWS Depth

Hands-on production experience with EC2, S3, RDS, IAM, VPC, ECR, and at least one of EKS, ECS, or Lambda.

Comfort owning deployment, monitoring, and cost.

System Design and End-to-End Ownership

Able to take an ambiguous problem, break it into components, evaluate alternatives, produce an architecture that holds up under review and load, plan execution, and ship with limited supervision.

AI-Assisted Engineering Experience

Daily use of Claude, Cursor, Copilot, or equivalent.

Strong discipline for reviewing and validating AI-generated backend code.

Excellent Written and Spoken English

Experience working directly with international clients.

Confident defending architectural choices in writing and in review.

Nice to Have:

• Workflow orchestration (Temporal, Airflow)
• GraphQL (Apollo, gRPC)
• Sandboxed execution environments
• Multi-tenant SaaS experience
• OpenTelemetry instrumentation
• Prior agency or consulting experience

About Root Node

We’re an early-stage startup building intelligent tools for planning, scheduling, and optimization—starting with timetabling and warehouse logistics. Backed by deep domain expertise and a growing customer pipeline, we’re now building our core tech team. This is not just a coding job — it's a chance to build something meaningful from the ground up.

About the job

• Design and implement robust backend systems and APIs using Java or similar backend language and Spring Boot or equivalent frameworks
• Integrate backend services with existing custom ERP systems 
• Work closely with the founder on product architecture, feature prioritization, and go-to-market feedback
• Take full ownership of features — from system design and development to deployment and iterative improvements
• Help shape our engineering culture and technical foundations

You're a Great Fit If You:

• Have 3+ years of experience in backend development
• Are strong in Java or similar languages (e.g., Kotlin, Go, Node.js)
• Have solid experience with Spring Boot or equivalent backend frameworks
• Have integrated with ERP or enterprise systems in production environments
• Are comfortable with both SQL (PostgreSQL) and NoSQL (MongoDB)
• Understand REST API development, authentication, Docker
• Have an entrepreneurial mindset — you're excited about ownership, ambiguity, and making decisions that shape the product and company
• Want more than just a job — you want to build, solve, and learn rapidly

What We Offer

• Competitive salary
• High degree of ownership and autonomy
• Ability to shape the tech and product direction from Day 1
• Transparent and fast decision-making culture
• A builder’s environment — solve real-world problems with real impact

Job description for Backend Developer:

Responsibilities
• Hands-on experience in Springboot and good knowledge of MySQL, MongoDB
• Hands-on experience in building RESTful based APIs
• Develop and manage well-functioning databases and applications
• Write effective APIs
• Integration of user-facing elements developed by front-end developers with server-side logic
• Building reusable code and libraries for future use
• Optimization of the application for maximum speed and scalability•
• Implementation of security and data protection

Skills And Qualifications
• Basic understanding of front-end technologies and platforms, such as JavaScript, HTML5, and CSS3
• Understanding accessibility and security compliance (Depending on a specific project)
• User authentication and authorization between multiple systems, servers, and environments
• Integration of multiple data sources and databases into one system
• Management of hosting environment, including database administration and scaling an application to support load changes
• Data migration, transformation, and scripting
• Outputting data in different formats
• Understanding differences between multiple delivery platforms such as mobile vs desktop, and optimizing output to match the specific platform
• Creating database schemas that represent and support business processes
• Implementing automated testing platforms and unit tests
• Proficient knowledge of a back-end programming language (Java 8 and above and Spring Boot)
• Proficient understanding of code versioning tools, such as Git
• Proficient understanding of OWASP security principles
• Understanding of “session management” in a distributed server environment

Required qualification:

*)  Any degree from a reputed university

*) Proven software development experience and Java/J2EE skills development. 

Strong proficiency with one of the Vue.js, Angular JS, React JS JavaScript Techologies
2. Knowledge of Node.js and frameworks available for it , such as Express JS, Strong Loop, etc
3. Understanding the nature of asynchronous programming and Promises and its quirks and workarounds
4. Good understanding of server-side templating languages (such as Jade, EJS, etc depending on your technology stack)
5. Good understanding of server-side CSS pre-processors such as Styles, Less
6. Basic understanding of front-end technologies, such as HTML5, CSS3, and Bootstrap
7. Understanding accessibility and security compliance
8. User authentication and authorization between multiple systems(Internal or Third party), servers, and environments
9. Integration of multiple data sources and databases into one system
10. Understanding fundamental design principles behind a scalable application
11. Understanding differences between multiple delivery platforms, such as mobile vs. desktop, and optimizing output to match the specific platform
12. Implementing automated testing platforms and unit tests
13. Proficient in code versioning tools, such as Git or TFS

We are looking for developers who are passionate about Python and know what are the benefits of python well.

Responsibilities:

• Design & implement new software modules based on the product requirements
• Debug existing software components, fix issues, and avoid regressions
• Be proactive, take ownership, and be accountable
• Familiar with Test Drive Development.
• Participate in software architecture, design discussions, and code reviews

Technologies we’re hiring for:

• Developed HTTP based REST APIs and implemented Authentication, Caching
• Worked with relational and NoSQL databases and aware of concepts like ORM, Migrations
• Languages & Frameworks: Python Django/Flask
• Database: Postgres/ Mongo
• Must have worked in a Unix/Linux based environment
• Advanced middleware like RabbitMQ, Celery Beat is definitely a plus.

Minimum 3+ year hands-on experience in Python needed

Following are the things that we are looking for in our NodeJS developer:

• Full SDLC knowledge, preferably in an agile environment.
• Strong written and verbal communication skills. Strong critical thinking & problem solving skills.
• Understanding of Unix / Linux based systems.
• Hands-on exposure to deeply linked relational databases – preferably in MySQL
• Ability to take a feature or product through the full Software Development Life Cycle.
• Strong communication skills, including the ability to both collaborate well and also the ability to convey technical ideas and concepts to non-technical stakeholders.
• Identify the interaction needs and how the API. must be developed based on design comps, product specs, etc.
• Continuously evaluate and implement new technologies to maximize development efficiency.
• Address and prioritize production level bugs and application performance improvements.
• An adaptable attitude and understanding of the agile methodology.
• Unit-test code for robustness, including edge cases, usability, and general reliability.
• Collaborate with cross-functional teams to define, design, and release new features.

NodeJS Developer:

We at Fabzen Technologies are looking for a knowledgeable and experienced individual to fulfil the role of Node.js developer.

Requirements:

• Bachelor’s degree in Computer Science, Software Engineering or related field.
• Professional experience on a software development team as a Node.js developer.
• Strong software documentation skills.
• Ability to comprehend and implement detailed project specifications as well as the ability to adapt to various technologies.
• Strong problem-solving skills.
• Understanding of Software Development Life Cycle.
• High attention to detail.
• Excellent troubleshooting and communication skills.
• Able to work well in a team setting.

The candidate must be proficient at:

• Socket programming
• Async await and promises
• Databases such as mongo, MySQL
• Passport JS for Google and Facebook integration
• Working on APIs with authentication and authorization

Responsibilities:

• Work closely with the development team to deliver code as required for the applications and their updates.
• Ensure the design and development of the application fulfil our requirements and achieve desired objectives.
• Ensure company standards are followed; Project schedules and issues are effectively managed, and the same is effectively communicated.
• Ensure documentation, knowledge sharing, and training in new software.
• Create technical specifications and test plans.
• Monitor the functioning of the application and provide suggestions and support to maintain the same.

Experience in a game development company or in developing gaming applications would be an added advantage.

Are you passionate about using technology to make people's lives better? Are you interested in becoming a part of one of the hottest trends in the world of start-ups today? Are you excited about joining the online ultra-fast grocery delivery service business pioneer and driving the trend forward? Then this may be the right opportunity for you.

Role and Responsibilities

1. Helping lead the software development lifecycle: technical design, implementation, testing, deployment, and support.
2. Working with cross-functional teams effectively to enable business growth.
3. Proactively identifying engineering bottlenecks and initiating proposals to improve them.
4. Writing high-quality, well-tested code in alignment with industry-wide best practices.
5. Applying a product mindset to back-end systems.
6. 1.  

1. About five years of experience delivering product-quality code in an agile set-up
2. Experience with Node.js (Hapi, Restify, Express, Mongoose, Socket.IO, Mocha)
3. Experience with Elasticsearch
4. Experience building and deploying Docker containers
5. Strong general Linux experience
6. Extensive experience with REST APIs
7. Experience with microservice architecture
8. Experience with MongoDB
9. Expert knowledge of Redis and caching strategies
10. Strong knowledge of unit/integration testing, including the art of mocking and writing testable code

1. Passionate about technology and making an impact.
2. A perpetual learner, who stretches their boundaries and enjoys new ideas.
3. A doer who takes initiative and works well in a team.

Blok is a technology-first online ultra-fast grocery delivery service business, and we are on our way to revolutionize how millions of people across countries consume groceries. We believe in a world where getting everything you need, when you need it, sustainably, is the new normal. And it takes less than 10 minutes.

We believe we are positioned to lead this revolution. Why? Our founding and early team have held senior positions at Deliveroo, Uber, Glovo, Mercadona, or Unilever. We have done this before, and we believe we can do it again. But this time, even better.

Embark on the journey and help us launch the revolution in one of the highest growth industries of the year. Help us shape the new normal.