Rohit Kumar

Full-stack creator monetization platform — content access gated by a real payment lifecycle, not a paywall toggle.

• Razorpay payment gateway with real-time webhook processing and HMAC-SHA256 signature verification for automated content access control.
• JWT authentication with Role-Based Access Control (RBAC) across 5 RESTful API endpoints, including automatic token refresh on role elevation.
• Payment lifecycle (pending → active → cancelled) enforced via PostgreSQL partial unique index constraints and JOIN-based authorization middleware — prevents duplicate subscriptions and privilege escalation.
• Deployed split-stack: Vercel (frontend), Render (backend), Neon PostgreSQL.

A second opinion on your submission — correctness, complexity, and pattern recognition, without handing you the answer.

• Automated correctness verification, time/space complexity analysis, algorithmic pattern recognition, and a two-stage Socratic hint system — no user authentication required.
• Custom multi-language harness generator parses LeetCode GraphQL API signatures into runnable Python, C++, and Java, executed in a self-hosted Judge0 sandbox.
• Groq LLM API integration with a structured JSON contract; PostgreSQL query caching via Drizzle ORM, pre-seeded with ~3,000 problems.
• Per-IP rate limiting to control inference costs. Built as a monorepo.

The Codeforces profile page, rebuilt — because the default one doesn't tell you where you're actually weak.

• Replaces the default Codeforces profile with a CP analytics dashboard: contest rating history, problem difficulty distribution, topic-level weakness detection, and a GitHub-style yearly activity heatmap via Chart.js.
• Codeforces Public REST API integration through a dedicated background service worker for MV3 compliance and separation of concerns.
• SPA navigation detection via the MutationObserver Web API — auto-reinitializes the dashboard on every client-side route transition.