Shashank Kumar

I’m a product-focused engineer who independently shipped a full-stack platform end-to-end—from feature planning and architecture decisions to production deployment and operations. I built SAFAR’s web (React/Express/MongoDB) and Android app (Kotlin/Jetpack Compose), serving 35,000+ registered and 8,000+ active users across a shared backend.

I take ownership of the hard parts: I integrated Razorpay end-to-end (order creation, HMAC signature verification, premium entitlement stacking with concurrency locks, refunds, and transaction history). I also built a real-time community feature (Mehfil) with Socket.IO (room messaging, reactions, comments, direct messages) and designed a moderation pipeline with admin report queues, automated filtering, and user-facing report flows.

I drive reliability and performance by diagnosing production issues and shipping targeted infrastructure improvements. For SAFAR, I integrated a CDN, added Redis caching with rate limiting (local fallback), and migrated uploads to Vultr S3 with Sharp image processing—cutting monthly bandwidth from 437GB and dropping server CPU from ~64% to 15–20%. On mobile, I directed the Android architecture using Clean Architecture (MVVM), Hilt DI, foreground-service focus timer, an AccessibilityService-based app blocker, and Firebase push notifications with per-channel preferences, quiet hours, and deduplication—shipping a 54K-line production Kotlin/Compose app. I’ve also built an AI-powered syllabus import pipeline (Python/FastAPI/Groq Llama 4 Scout) that converts PDF/DOCX syllabi into structured study plans powering exam templates, calendar view, plan generation, and insights analytics.