Backend 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.

Location - Pune/ Mumbai/ Bangalore

Education

Degree, Postgraduate in Computer Science or related field (or equivalent industry experience)

Experience

• Minimum 5 years of coding experience in NodeJS, JavaScript and Databases.
• At least 1 year hands-on in TypeScript .
• Hands-on experience in performance tuning, debugging, monitoring

Technical Skills

• Excellent knowledge developing scalable and highly-available Restful APIs using NodeJS technologies
• Practical experience with GraphQL.
• Experience in working with AWS platform and its core services like Lambda, Cloud Watch, Cloud Formation, CDK, SQS, S3 etc., or its equivalent Azure services
• Hands-on working experience in front-end applications development with HTML, CSS, Node JS with strong working experience in backend technologies Java, TypeScript and JavaScript programming languages.
• Understanding of containerization, experienced in Dockers , Kubernetes.
• Exposed to API gateway integrations like 3Scale.
• Understanding of Single-Sign-on or token-based authentication (Rest, JWT, oAuth)
• Experience on DevOps ways of working with good understanding on CI/CD and actively involved in solving, troubleshooting issues in distributed services ecosystem
• Hands on experience with both SQL and No-SQL databases.
• More than 3 years proven experience in developing high volume scalable cloud solutions utilizing platforms like Amazon AWS or Microsoft Azure.
• Possess expert knowledge of task/message queues include but not limited to: AWS, Microsoft Azure, Pushpin and Kafka

Functional Skills

• Experience in following best Coding, Security, Unit testing and Documentation standards and practices Experience in Banking, Financial and Fintech experience in an enterprise environment preferred
• Experience in Agile methodology.
• Ensure quality of technical and application architecture and design of systems across the organization.
• Effectively research and benchmark technology against other best in class technologies.

Soft Skills

• Able to influence multiple teams on technical considerations, increasing their productivity and effectiveness, by sharing deep knowledge and experience.
• Self-motivator and self-starter, Ability to own and drive things without supervision and works collaboratively with the teams across the organization.
• Have excellent soft skills and interpersonal skills to interact and present the ideas to Senior and Executive management

Key Responsibilities: 

• Rewrite existing APIs in NodeJS. 
• Remodel the APIs into Micro services-based architecture. 
• Implement a caching layer wherever possible. 
• Optimize the API for high performance and scalability. 
• Write unit tests for API Testing.
• Automate the code testing and deployment process.

Skills Required: 

• At least 3 years of experience developing Backends using NodeJS — should be well versed with its asynchronous nature & event loop, and know its quirks and workarounds. 
• Excellent hands-on experience using MySQL or any other SQL Database. 
• Good knowledge of MongoDB or any other NoSQL Database. 
• Good knowledge of Redis, its data types, and their use cases. 
• Experience with graph-based databases like GraphQL and Neo4j. 
• Experience developing and deploying REST APIs. 
• Good knowledge of Unit Testing and available Test Frameworks. 
• Good understanding of advanced JS libraries and frameworks. 
• Experience with Web sockets, Service Workers, and Web Push Notifications. 
• Familiar with NodeJS profiling tools. 
• Proficient understanding of code versioning tools such as Git. 
• Good knowledge of creating and maintaining DevOps infrastructure on cloud platforms. 
• Should be a fast learner and a go-getter — without any fear of trying out new things Preferences. 
• Experience building a large scale social or location-based app.

Responsibilities

• Produce clean, efficient code based on specifications
• Integrate software components and third-party programs
• Verify and deploy programs and systems
• Troubleshoot, debug and upgrade existing software
• Gather and evaluate user feedback
• Recommend and execute improvements
• Create technical documentation for reference and reporting

Requirements and skills

• 1-3 Years of Proven experience as a Backend Developer
• Tech Stack:

• AWS- Lambda, ECS, RDS Arora, RDS PostgreSQL, DynamoDB, S3, SQS, APIG, Cloud Front
• NodeJS
• Typescript(optional)

• Familiarity with Agile development methodologies
• Experience with software design and development in a test-driven environment
• Ability to learn new languages and technologies
• Excellent communication skills
• Resourcefulness and troubleshooting aptitude
• Attention to detail

About us:

Siply helps underserved masses inculcate savings behaviour to build a more productive and financially secure country. Our Vision is to build the Digital Bank for 40 Crore Underserved Indians.

Company Link - https://siply.in/">https://siply.in/

About the Role:

This is the Senior role where you will build systems and infrastructure to enable seamless user experience across all our offerings in the space of Micro-Savings, Micro-Credit, Micro-Insurance, and associated Value-Added Services. You will power the user experiences on the App and translate complex technical issues into Business opportunities.

Responsibilities:

• Build the architecture for our Product platforms and take ownership for deliverables.
• Good Understanding of all stage of software development and also mentoring team.
• Design some of the most advanced & complex software systems / products in the industry.
• Determine technical feasibility of medium to low complexity features or solutions by evaluating problem, possible solutions and technology requirements.
• Exercise judgement in prioritizing tasks and selecting methods and techniques for obtaining solutions.
• Collaborate and work closely with Engineering, Product and Design team.

Requirements:

• 4 to 7 years of experience in software product development.
• Degree in Computer Science or related field from top tier universities is preferred.
• Excellent abstraction, coding and system design skills.
• Strong hands-on technology experience building and running large scale systems handling multi-million sessions/transactions per day.
• Strong experience in large scale Database systems like rdbms & NoSQL stores.
• Excellent programming skills in Java/GO/NodeJS and expertise in multi- threading and performance-oriented programming.

Join us to be a part of our Growth Journey!

• Engage in Node.js back-end development with MongoDB
• Work on Backend programming
• Work on databases
• Coordinate with front end teams for overall project overview
• Create User stories and UML, documentation of the business goals

• Must have knowledge of Node.Js, HTML, CSS
• Knowledge of git and AWS  
• Proficient in Data Structures and Algorithms  
• Good in Object oriented design
• Ability to work independently and manage the entire backend of all platforms associated with Rejolut
• Exemplary tasks – Explore something new every day!
• Responsibility – Bring in your own ideas and get supported in executing them. 
• Fun – Experience a family culture & celebrate with the founders & team.
• Team – Be a part of a high-performance & cultural diverse team

• Freshers can apply
• Students in their last semester or passed out in 2020 can also apply

• Working days: Monday to Friday
• Timings: 11:00 am to 7:00 pm
• Duration of internship: 6 months/PPO(Performance Basis)

• You are available for the above said duration.
• You prefer to work in a fast paced environment with growth & learning opportunities
• If you have not applied for an internship before with us.
•  have relevant skills and interests

•  Health Insurance
•  Work from Home
•  Fast growth and more visibility into the company
•  Experience to work on the latest technology
•  Competitive Learning Environment with supportive co-workers
•  Employee friendly HR Policies
•  Paid leaves up to certain limits
•  Liberal working atmosphere
• Get mentored by the best in the industry