I build scalable backend systems and polished web products for companies like ShareTrip, ChillyPOS, and HalalExplore - spanning flight booking engines, multi-tenant SaaS, e-commerce, and realtime platforms with React, Next.js, Node.js, NestJS, and cloud queues.
3+
Years of experience
400+
DSA problems solved
Specialized in backend-heavy, full-stack products across travel tech, SaaS, e-commerce, and realtime platforms.
End-to-end product delivery with React, Next.js, Node.js, and polished API contracts that teams can build on.
Scalable service architectures with NestJS, RabbitMQ, Redis, and PostgreSQL for high-throughput domains.
Multi-tenant backends with RBAC, subscription billing, BullMQ job queues, and real-time WebSocket flows.
Flight booking engines, halal travel APIs, idempotent bookings, vendor integrations, and queue-based reconciliation.
Worked With
A selection of full-stack applications, robust microservices, and AI-powered platforms I've engineered.
sharetrip.net
Travel Tech
End-to-end travel platform serving flights, hotels, and holiday packages with complex booking engines.
Impact: Production travel platform work across booking, post-booking, and airline integration flows.
chillypos.com
SaaS
Cloud-based Point of Sale and inventory management software designed for retail businesses with real-time syncing.
Impact: Multi-tenant backend and dashboard workflows for 100+ paying businesses.
halalexplore.com
Travel Tech
Halal-compliant travel ecosystem offering verified accommodations, transfers, and packages globally.
Impact: Backend APIs for hotel, cruise, transfer, insurance, and package booking workflows.
rashid-mamun.github.io/tech-interview-hub
Open Source
A comprehensive open-source guide and resource hub for technical interviews, covering backend, system design, and algorithms.
Impact: Public learning resource focused on backend, system design, database, and networking depth.
github.com/rashid-mamun/bdshop-server
Full Stack
Full-stack e-commerce system with a TypeScript client and scalable API for products, carts, orders, reviews, users, and stock workflows.
Impact: Full commerce API and client covering catalog, cart, order, review, and stock flows.
github.com/rashid-mamun/ride-hailing-microservices
Microservices
Microservices backend for ride booking with NestJS, PostgreSQL, RabbitMQ, Redis, Docker, and Swagger documentation.
Impact: Service-oriented ride workflow with brokered events, cache strategy, and documented APIs.
github.com/rashid-mamun/recruitAI
AI SaaS
AI-powered recruiting automation app with real-time SSE streaming, multi-tier AI fallback, and fault-tolerant candidate sourcing.
Impact: Fault-tolerant AI sourcing workflow with streaming UX and multi-tier provider fallback.
github.com/rashid-mamun/chat-app-backend
Full Stack
Full realtime chat system with React/Vite frontend and Socket.IO backend supporting private/group chats, file sharing, reactions, search, and 2FA.
Impact: Realtime messaging system with durable chat records, files, reactions, search, and 2FA.
github.com/rashid-mamun/halal-explorer-backend
Travel API
Backend for a halal-compliant travel platform covering hotels, cruises, transfers, insurance, and travel packages.
Impact: Travel backend surface covering verified halal inventory and authenticated API flows.
github.com/rashid-mamun/lets-form-a-team-nest-js
Auth/RBAC
Account type and role-based management system with granular permissions for super admin, manager, and employee flows.
Impact: Role and account-type management with granular permission boundaries.
sharetrip.net
Backend Arch
Architected the backend rewrite for flight void, refund, and reissue flows to handle complex airline ticketing rules.
Impact: Reduced operational complexity for flight void, refund, and reissue rule handling.
sharetrip.net
API Design
Designed backend API architecture for post-booking services, handling complex logic for dynamic seat selection and extra baggage.
Impact: Post-booking architecture for dynamic seats, baggage, and airline ancillary flows.
sharetrip.net
Backend Arch
Architected the backend engine for combo-flight search and booking, optimizing segment matching and dynamic pricing.
Impact: Search and booking engine work for segment matching and dynamic combo-flight pricing.
sharetrip.net
Cloud/AWS
Engineered a scalable flight logging system leveraging AWS S3 for file storage instead of traditional RDS, successfully reducing database costs by 30%.
Impact: S3-based flight logging approach that reduced database cost by 30%.
Practical notes on AI agents, backend systems, booking APIs, and full-stack product delivery.
Jun 2, 2026
9 min read
A field guide to giving coding agents enough context to help without handing them decisions they are not equipped to make.
May 28, 2026
8 min read
AI is often more useful as a small step inside an existing workflow: extract, rank, draft, validate, then let the user decide.
May 21, 2026
8 min read
A review sequence for generated patches, starting at the trust boundary and ending with the code the team will have to operate.
May 14, 2026
10 min read
The retrieval pipeline starts with permissions and document quality, long before a model gets a chance to answer.
May 7, 2026
11 min read
Lessons from flight systems where price, payment, booking, and ticketing can all disagree at the same time.
Apr 29, 2026
10 min read
What changed when a multi-tenant POS backend had to serve real businesses instead of a single demo tenant.
Engineering notes, project updates, and no spam.
Active on GitHub spanning full-stack commerce, microservices, AI tooling, realtime chat, and travel platforms.
An AI-powered recruiting automation app featuring real-time SSE streaming, multi-tier AI fallback, and fault-tolerant candidate sourcing.
Ride-hailing microservices backend with NestJS, PostgreSQL, RabbitMQ, Redis, Docker, and Swagger documentation.
Real-time chat application backend with private messaging, group chats, and file sharing.
A scalable RESTful API for an e-commerce platform, built with Node.js and MongoDB.
Halal-compliant travel platform for hotels, cruises, transfers, and packages.
Tech Interview Hub - Backend, System Design, Database, Networking, Docker, Node.js and NestJS interview notes