My Projects

Bangla-first, multi-tenant SaaS for Bangladeshi tailor shops: custom measurement fields, order workflow, and dues — built for owners who may not read fluently.

• Multi-tenant from the first migration — composite uniqueness, one auth seam
• Shop-defined garments and measurement fields stored as JSONB, no migration per shop
• Measurements frozen onto each order, so history never rewrites itself
• Six-stage workflow (গ্রহণ → কাটিং → সেলাই → ট্রায়াল → প্রস্তুত → ডেলিভারি) read by colour and icon
• Gap-free per-shop order numbers, allocated inside the order transaction
• Whole-taka integers with an append-only payment ledger; balances always derived
• + 4 more in the case study

File storage where a 500 MB upload costs the server two small JSON requests: the browser sends chunks straight to object storage, and every file is private until you publish a link you can take back.

• Presigned S3 multipart uploads: bytes go browser to storage, three parts in flight, per-part retry
• Post-upload verification — real size checked against the declared size, magic bytes sniffed from a 4 KB range read
• Executables rejected on signature, including the Mach-O/Java 0xCAFEBABE collision
• Ownership enforced in the WHERE clause; another account's file returns 404, never 403
• Share links are unguessable slugs, and revoking one destroys it permanently
• Rotating refresh tokens with family-wide revocation when a used token is replayed
• + 5 more in the case study

Book catalog and wishlist platform with token auth, search, reviews, and CRUD for verified users.

• Token-based (JWT) authentication and protected routes
• Search by book title, author, and genre
• CRUD operations for verified users
• Review posting and reading system
• Personal wishlist management
• Responsive UI with Redux state management