Hello, I'm

Sahiljeet Singh Kalsi

Full-Stack Engineer · 1.5+ years

Scale & Cost

40% lower cloud cost, 32→4 core footprint

0→1 Builder

Ships full-stack + AI products end-to-end

I take products from 0 to 1, then make them cheap to run at scale.

Full-stack engineer working across Node.js, NestJS, TypeScript, PostgreSQL, Redis, and AWS. I've cut cloud infrastructure costs by 40% through query and network optimization, and shipped multiple products end-to-end, from backend to deployment, often leaning on AI tooling to move faster.

cut in cloud infra cost

microservices migrated to AWS

0k+

concurrent users served

My Work: Senior Full-Stack Developer at Newral - Build scalable backend systems, infrastructure, and distributed services for production applications serving 100,000+ concurrent users.

Open to software engineering opportunities involving distributed systems, infrastructure, and scalable application development.

Experience

Newral

Noida, Uttar Pradesh · On-site

Sep 2025 - Present

Software Engineer

Jan 2026 - Present

Own full-stack delivery on Competishun and Synapse, from query performance and infrastructure cost to the features users see.

Competishun

EdTech platform for JEE/NEET aspirants with 100,000+ active users, served concurrently across a ~9-microservice architecture.

Reduced backend CPU usage from ~99% to ~25% through SQL query optimization, Redis caching, and workload restructuring.
Rebuilt the FFmpeg-based video transcoding pipeline, cutting processing time from 6 hours to under 30 minutes.
Cut cloud infrastructure cost by 40% by optimizing SQL queries and consolidating cross-service network calls onto a single network path, shrinking compute footprint from 32 cores to 4.
Led the migration of 9 microservices from GCP to AWS, improving scalability, reliability, and cost efficiency.
Resolved critical production issues across multiple microservices, leading to a ~90% reduction in app crashes.

Synapse

Multi-tenant platform for creators and EdTech businesses to sell courses and products and engage their audience. Currently onboarding pilot clients.

Building the platform with NestJS, TypeScript, Prisma, and React.
Own architecture decisions for a multi-tenant system serving multiple EdTech businesses from a single codebase.

Client projects

Backends for two separate US-based clients.

Designed and built the entire backend solo for Upto, a social media application, with NestJS, TypeScript, Prisma, and PostgreSQL.
Modeled the core social data layer (feed, relationships, content) for scale from day one.
Developed a scalable real-time backend with Node.js, Express, Redis, and WebSockets for a separate US-based startup.

Across all projects

Set up CI/CD pipelines with GitHub Actions and unit and integration test suites.
Used AI-assisted development tools (GitHub Copilot, Claude Code, Antigravity, Cursor, and custom AI agents) to speed up delivery while maintaining code quality.

Junior Software Developer Intern

Sep 2025 - Dec 2025

Built and maintained microservices using NestJS, TypeScript, PostgreSQL, Redis, and BullMQ.
Handled large-scale data operations across multiple SQL and NoSQL databases.
Resolved production issues across distributed microservices by analyzing application logs, improving system stability and reliability.

Unite Creatives

New Delhi, Delhi · Volunteer

Feb 2025 - Oct 2025

Programming Challenge Head

Volunteer role leading the programming side of a creative community with over 5,000 members.

Led coding challenges for the community.
Handled anything coding related for the organization, working mainly with JavaScript and REST APIs.

Tech Access Learning Pvt Ltd

New Delhi, Delhi · On-site

Jul 2023 - Dec 2023

Mobile Application Developer

Worked on native Android and cross-platform mobile apps.

Built a local MP3 player in Kotlin (Android Studio) with playlist management and media controls.
Developed a cross-platform movie bookmarking app in React Native with persistent storage.
Learned mobile application architecture across native Android and cross-platform development.
Strengthened debugging and deployment skills, delivering functional mobile apps under tight deadlines.