NodeJS Developer

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.

FirstFiling is a FinTech startup that is managed, operated, and driven by Chartered Accountants, Company secretaries, IT engineers, and Lawyers. We provide registration and financial compliance services to businesses and individuals across India.

Our aim is to simplify the lives of people by helping individuals and businesses with mandatory compliances, filings, and statutory requirements while promoting financial literacy among the masses. 

Role: Backend Developer (2 openings)

Basic Qualifications:

• 2+ years of non-internship professional software development experience
• Programming experience with at least one modern language such as Java, C++, or C# including object-oriented design
• 1+ years of experience contributing to the architecture and design (architecture, design patterns, reliability and scaling) of new and current systems.

Additional Job requirements

• BS/MS/PhD in Computer Science/Math or equivalent
• BS in computer science or related field.
• 2+ years of relevant professional software development experience: designing, developing, and delivering software written in Java, C#, or C++, web development.
• Knowledgeable in object-oriented design patterns.
• Experience building highly scalable and distributed systems

Preferred Qualifications

• Experience with service-oriented architecture and application/services development
• Passion for performance debugging and benchmarking
• Ability to clearly and concisely communicate with technical and non-technical stakeholders across all levels of the organization

As a senior software engineer, you will contribute to our end-to-end supply chain platform. You'll work with all key stakeholders to deliver scalable, maintainable backend code and work with frontend developers to deliver amazing user experiences. We are building a design and process-centric culture where you'll play a key role in the implementation of the foundation of all our systems. Up for a challenge?

You are:

• A self-starter with a sense of what it takes to be successful as a team
• An agile - welcome change, do as little as possible and embrace continuous delivery
• Conscious about how quality is carried through from the UI to all layers underneath
• Opinionated, but flexible to accommodate the big picture

Responsibilities

• Analyze requirements, provide estimates and deliver code in an agile setup
• Stay on top of all owned work and raise red flags as early as possible
• Define the architecture, best practices, and coding standards
• Support continuous technical improvement by investigating alternatives and technologies and present them for architectural review 
• Motivate team members, coach junior members, and extend goodwill to other employees