Vlynq

Built a role-based marketplace experience for buyers and creators, with dual-role accounts that let users switch between buying and selling modes.

Built a resumable multipart upload pipeline for large video files: browser chunking, presigned S3-compatible URLs, concurrent part uploads, and database-backed session recovery for resume-after-refresh.

Integrated Cloudflare R2 as S3-compatible object storage with file lifecycle metadata for source files, generated previews, thumbnails, message attachments, references, and saved files.

Built a background FFmpeg media worker that generates smart thumbnails (sampling multiple frames to pick the best), watermarked video previews, and resized delivery variants for large source videos. Errors are classified (corrupted video, unsupported format, missing source, storage failure).

Added signed-URL access control for private media downloads with ownership, purchase, participant, and admin checks before serving files.

Integrated Razorpay checkout for video purchases and storage upgrades with server-side price validation, signature verification, webhook fallback, transaction records, purchase records, platform fees, and creator revenue tracking. Prevented duplicate purchases, self-purchases, and client-side price tampering.

Designed Supabase / PostgreSQL schemas with Row-Level Security policies, SQL migrations, RPC functions for purchase creation and storage upgrades, and triggers for status synchronization.

Used Zustand for client-side role and upload state, with security headers, CSP configuration, and service-role access scoped to webhooks and workers.