Architecting scalable platforms with sub-100ms real-time delivery
I am Karan Kumar. I build production-grade telecom pipelines, secure multi-tenant SaaS matrices, and high-throughput systems that turn intensive, event-driven requirements into seamless user experiences.
About Me & My Approach
I architect mission-critical communication layers, secure multi-tenant backends, and low-latency systems engineered to handle real user traffic under heavy load.
Hi! I'm Karan Kumar, a Full Stack Engineer specialized in building high-scale production apps using Next.js, TypeScript, Node.js, and Redis. Currently, I engineer real-time healthcare telephony platforms scaling to 30,000+ monthly calls with sub-100ms state responsiveness.
My core expertise lies in bridging communication protocols like WebRTC, JsSIP, and Asterisk PBX alongside production-grade security patterns like strict multi-device session handling, advanced RBAC models, and data isolation layers.
Backed by deep algorithmic discipline with 500+ LeetCode solutions focused on Dynamic Programming and Advanced Graphs, I focus on system bottlenecks, memory optimizations, and writing predictable, highly maintainable code.
Skills & Technical Arsenal
Resume-aligned strengths across full stack engineering, real-time systems, telephony infrastructure, and production-grade security.
Core Focus
Scalable product engineering
Real-Time Delivery
Sub-100ms state synchronization mindset
Reliability
Security-first, production-ready architecture
Languages
Frontend
Backend
Databases
Real-Time
Telephony
Security
DevOps & Tools
Focused on building robust systems that are secure, maintainable, and built for scale from day one.
Featured Projects
LMS
An AI-powered learning management system that offers mock interviews, course creation, video security, and authentication features.
- AI-powered mock interview workflows
- Secure video delivery with VdoCipher
- Role-aware dashboard and learning modules
NextGen Backend System
A production-grade backend platform built with Node.js and Express to demonstrate secure authentication, session management, Redis caching, RBAC, and real-time collaboration architecture.
- JWT access/refresh token strategy with multi-device sessions
- Security hardening: account lockout, rate limiting, request validation, and audit logs
- Socket.IO-based collaborative rooms with chat, live code sync, and snapshots
- Scalable modular architecture with Redis-backed real-time support
AcePrep
A comprehensive preparation platform for web development, DSA, and technical interviews with interactive mock interviews, MCQs, and performance tracking.
- Mock interview workflows with role-based prep tracks
- Performance analytics and practice roadmap
Mentorship Platform
A platform designed to connect mentors and mentees, enabling meaningful career growth and skill development.
Expense Manager
A real-life expense management solution that helps groups track shared expenses and ensure fair contributions.
AI Interview Platform
An AI-driven interview platform that generates tailored interview questions based on the role, question count, and type.
BTech Burger Vala
A food ordering platform with a simple and user-friendly interface.
Social Media Platform
A fully functional social media application built using the MERN stack.
Music Streaming Platform
A basic music streaming platform with a modern UI.
College Appointment Backend
A backend system for managing college appointment scheduling and student interactions.
Experience & Impact
Professional experience and measurable outcomes aligned with your resume.
Full Stack Developer
OD3X / CX Assist Ltd
AI-Powered Healthcare Communication Platform | London, UK (Remote)
Scaled telephony infrastructure from 0 to 30,000+ monthly calls while maintaining sub-100ms UI responsiveness and 99.9% uptime.
Built browser softphone architecture using JsSIP, WebRTC, and Asterisk PBX with SIP signaling, STUN/TURN, IVR flows, transfers, and recording workflows.
Engineered multi-tenant data isolation and hierarchical RBAC architecture for secure clinic-level sandboxing.
Replaced heavy polling with Redis Pub/Sub + WebSockets for low-overhead event broadcasting across 20+ active clinic setups.
Algorithmic Excellence
Solved 500+ DSA problems with strong focus on graphs, dynamic programming, and system design thinking.
Product Ownership
Core engineer delivering production-grade real-time tooling used daily by professional teams under high-volume operational scenarios.
View GitHub →LeetCode Profile
Competitive and consistent coding profile showing strong algorithmic discipline and continuous improvement.
View LeetCode →GitHub Contributions
Current Focus
I am looking to contribute to forward-thinking teams where I can architect high-throughput systems, real-time engines, and bulletproof security infrastructure.
High-Scale Full Stack
Engineering high-throughput, distributed web systems tied to measurable performance targets and seamless user experiences.
Real-Time Engines
Architecting low-latency communication networks utilizing WebRTC, WebSockets, and robust event-driven patterns.
Secure Infrastructure
Implementing hardened architectures featuring advanced authentication protocols, rigorous RBAC, and strict data isolation.
High-Impact Culture
Thriving within collaborative, engineering-first teams that champion extreme ownership, code quality, and fast shipping loops.