Ahsan Ahmed

Skills & Expertise

Architecture, Backend & System Design patterns

• Laravel & PHP (Advanced): Breeze, SOLID, Multi-tenant SaaS, MVC and Data Isolation. Achievement: Designed multi-tenant architecture and stock/batch ledgers for a Pharmacy POS SaaS, ERP, HRM, E-commerce,.
• Architecture: API/Web/Worker separation, Load Balancing, System Design, and Legacy Refactoring. Achievement:
  1. Refactored legacy core modules in OTA platform, improving performance and downtime resolution.
  2. Architected high-throughput API gateways and background worker systems for ota, ensuring 99.9% uptime by isolating long-running pricing sync tasks from the main web thread
• Design Patterns: Expert in Service-Repository Pattern, using Interfaces for decoupling, Traits for code reusability, and Action Classes for thin controllers. Achievement: Implemented modular architecture in Pharmacy POS and ERP systems to ensure high maintainability.
• System Design: Separated systems into Web, API, and Background Workers to handle high traffic; expert in Legacy Refactoring to modernize old codebases without downtime. Achievement:
  1. Refactored legacy OTA core modules, reducing system latency by 50%(2x faster) and improving reliability through optimized API-first architecture and service decoupling. made significantly more stable
• Jobs & Task Automation: Redis Horizon, Queue Workers, Caching, and Invalidation patterns. Achievement: Built robust queue-driven pipelines using Redis to handle 100k+ real-time availability updates, ensuring data consistency across external supplier APIs..
• Rest API & Security: OAuth (Sanctum/Passport), API Tokens, Rate Limiting, Throttling, and Permissions management. Achievement: Developed secure, high-performance APIs for a large-scale file transfer platform (BDRen) and resolved critical travel-data synchronization bottlenecks through rate-limiting and payload optimization.
• Payment Gateways (PGs): SSLCommerz, PayPal, Stripe, bKash, Aamarpay, Surjopay, TNG, CHIP.

Databases & Optimization

• Database Management: MySQL, PostgreSQL, MariaDB, and SQLite performance tuning. Achievement:
  1. Enhanced DB performance by 3x through Query Profiling and Indexing strategies, specifically resolving bottlenecks in complex B2B booking and pricing calculation engines.
  2. Utilized Database Sharding & Partitioning to optimize high-volume data performance.
• Eloquent ORM: Complex migrations, relationship mapping, and data optimization.
• Realtime DB: Firebase Auth & Realtime Database, MongoDB.

DevOps, Cloud & Infrastructure

• Cloud Services: Vultr, AWS (S3, EC2), VPS, cPanel, and Docker management.
• Server Administration: Ubuntu server installation, Nginx config, manual PHP setup, and Composer.
• CI/CD & Deployment: GitHub Actions, Bitbucket, manual/auto pipelines, and SSH deployment automation. Achievement: Reduced deployment time by ~80% via Git-based release workflows.
• Reliability & Backup: Supervisor / systemd for queue reliability and automated pipelines (Google Drive, FTP). Achievement: Automated secure cloud backups and server deployment workflows, reducing manual maintenance overhead and ensuring rapid disaster recovery.

Frontend & Leadership

• Frontend Interactivity: Blade, Mix/Vite bundling, jQuery, AJAX, Parsley.js, Angular, HTML5/CSS3, Bootstrap. Achievement: Integrated Next.js frontend with Laravel APIs and built complex SEO-focused pricing UIs.
• Modern JS Stack: React & Next.js (Learning process), MERN Stack (Upcoming).
• Lead & Process: Agile (JIRA, Trello), Mentoring, Requirement Analysis, and Sprint delivery. Achievement: Led small backend teams through code review and technical onboarding.