Node.js Developer

Job Title : Senior Backend Developer (Node.js + AWS + MongoDB)

Experience : 4+ Years

Location : Andheri, Mumbai (Work From Office)

About the Role :

We are looking for a highly skilled Senior Backend Developer with strong expertise in Node.js (NestJS), AWS, and MongoDB to join our growing engineering team.

This role requires someone who takes ownership, is proactive, and enjoys building scalable, high-performance backend systems in a fast-paced environment.

Key Responsibilities :

• Architect, design, and develop scalable backend services using Node.js (NestJS).
• Design and manage cloud infrastructure on AWS Services (EC2, ECS, RDS, Lambda, etc.).
• Develop and maintain high-performance database solutions using MongoDB.
• Work with Kafka, Docker, and serverless frameworks (SST) for efficient deployments.
• Optimize system performance, scalability, and reliability across services.
• Ensure application security, best practices, and compliance standards.
• Collaborate with cross-functional teams to deliver robust product features.
• Take end-to-end ownership of features from design to deployment.

Technical Requirements :

• 4+ years of backend development experience.
• 3+ years of hands-on experience with Node.js.
• 2+ years of hands-on experience with AWS.
• Strong experience with NestJS framework.
• Solid experience with MongoDB and database design.
• Experience with Kafka, Docker, and serverless architecture.
• Understanding of system design, scalability, and performance optimization.

Good to Have (Bonus Skills) :

• Experience with Python or other backend languages.
• Exposure to Agentic AI use cases or implementations.
• Strong understanding of security best practices.

What We’re Looking For :

• Curious mindset and eagerness to learn new technologies.
• Proactive problem solver with strong ownership attitude.
• Strong team player with effective communication skills.
• Positive, energetic, and passionate about building great systems.

Core AI Backend Engineer – LLM Fine-Tuning

You know that moment when you don’t just debug code — you train a model, fine-tune it, and suddenly it understands your domain better than you expected? That’s the kind of magic we’re looking for.

We’re building something that turns chaotic social video data into crystal-clear business intelligence. Not just another API — but AI-backed architecture fine-tuned to our world. Systems that marketing teams thank you for, because they feel the intelligence, not just the infrastructure.

Either you feel the craft when you read this, or you don’t. This isn’t just another backend role. This is where you bring together scalable systems and cutting-edge LLMs to build something the world hasn’t seen before.

Who We Are

We’re a small, global team that ships fast. Every line of code and every model choice affects millions of video analysis requests.

Our engineers don’t just build APIs — they architect solutions, they optimize at scale, and now, they fine-tune models to make AI work in the real world. Our CPTO still codes. Our senior engineers make complexity look effortless. Our backend team sets a standard that others ask how we move so fast.

What We Need

We need someone who’s lived both sides of this life:

• Backend excellence: building high-scale, high-performance systems.
• LLM fine-tuning: hands-on with open-source models, not just calling APIs.

Someone who can sit with a requirement at 2pm and by 6pm not only has endpoints working, but also has a fine-tuned model running behind them — customized to our use case.

Your Craft

• JavaScript/TypeScript & NodeJS as core backend tools.
• Next.js for full-stack where needed.
• Rust when performance is non-negotiable.
• Golang/Python as comfortable tools of choice.
• MySQL/Postgres/Redis — wielded with intention.
• AWS ecosystem — your playground, not your puzzle.
• LLM/AI integration you’ve actually shipped.
• Open-source LLM fine-tuning experience:
• Bringing in open-source models (LLaMA, Mistral, Falcon, etc.).
• Fine-tuning/adapting them for specific domains.
• Optimizing for inference cost, latency, and accuracy.

The Reality

The work is beautifully complex. The scale is real and growing. The problems are the kind that wake you up at 3am with solutions.

If you get your energy from building backend systems and adapting LLMs to make them smarter for real-world use, you’ll probably fall in love with what we do. If you’re only interested in APIs without touching models, this won’t be your thing — and that’s completely okay.

How to Apply

If you’re reading this thinking “finally, a team that actually cares about real AI engineering” — we’d love to see something you’ve built.

Not just a resume. Show us your craft:

• An LLM fine-tuning repo.
• A domain-adapted model you worked on.
• A system design where you combined backend and AI.
• Or even a short write-up or voice note explaining what you’ve fine-tuned.

We’re genuinely excited to see what you’ve done and have a meaningful conversation about whether this could be magic for both of us.

Ideal candidate must have :

- 2+ years of experience in writing code

- Ability to meet tight deadlines

- Can work independently and be a team contributor

- Must have good knowledge of Node, Python and Scripting languages

- Experience in one or more of RDBMS - PostgreSQL, MySQL or Oracle

- Experience with NoSQL and real-time DB - Firebase/Firestore or MongoDB

- Must be able to write concise and high-quality API

- Must be a quick learner, curious and ambitious  

AnnexLogic System Pvt. Ltd. is a leading comprehensive business software product development services provider. We partner with both start-ups and established businesses globally in their idea-to-implementation journey. We are a team of professionals who believe in creating business value for our clients through in-depth research, analysis, formation and implementation. Our customers are spread across the globe including the US, Canada, Australia, UK, Europe and Asia-Pacific region.

We are always looking for opportunities to extend our team with new proficient and talented colleagues who love working in a start-up culture, and this time, we need a Senior Back-end Developer, with strong technical skills and relevant experience of at least 4 years.

You’re a motivated team player who takes initiative and pride in his work and contributes to an informal working environment. You will be confident in your ability to develop the product, taking into account the following:

● Excellent knowledge of NodeJS
● At least 3 years of working experience with backend technologies
● Knowledge of PHP is considered a plus
● Knowledge of Java or Kotlin is considered a plus
● You can learn quickly new technologies and adapt to new technical challenges
● Experience in working with a TDD approach
● You have a strong background in Linux-based development
● You have previous experience with container technologies such as Docker
● You have strong knowledge of microservice architecture
● You are passionate about writing clean, maintainable & testable code
● You have strong Agile/Scrum work ethic
● You are continuously researching tools, technologies, frameworks and practices.
● Projects with a high complexity interest you
● You are highly committed and responsible, independent and able to take an initiative
● You are always mindful of quality attributes like maintainability, performance, security, scalability, usability and testability.
● You carefully read the specifications and assignments and you like to take responsibility for your components from start to end
● You feel comfortable discussing and deepening technical and technical requirements with the PM
● You have multitasking capabilities, attention to detail and excellent analytical skills
● Excellent interpersonal and teamwork skills 1 Responsibilities:
● Work on multiple microservices - written in NodeJS (TS, JS), Spring (Kotlin), PHP (Symfony)
● Develop new microservices to accommodate the (many) new features and requirements of the project
● Refactor existing microservices or extract new ones to improve performance and scalability
● Come up with ideas to improve existing architecture - feedback and ideas are always welcome
● Monitor, trace and debug production microservices to ensure an application with 0 downtime
● Work to improve the CI / CD flow of the project Things we can guarantee:
● Competitive salary, with many other extra benefits (complex medical package, extra free days, events, gifts and others)
● Opportunity to work on a challenging project, using the latest technologies
● The perfect framework for professional development
● A young, creative and friendly team
● A flexible work schedule which makes you more productive
● We support any opportunities that are useful for you, including training and events