Mahmudul Hassan

Tech Lead – Software Engineer

Gold Kinen • Fulltime

Nov 2022 - Present • 3 yrs 6 mos

At Goldkinen Technology in Dhaka, I joined as a Senior Software Engineer in December 2022 and was promoted to Tech Lead for modernizing Bangladesh’s first certified gold trading platform. I led the migration from Oracle + PL/SQL to FastAPI + PostgreSQL, moving core business logic to the application layer for better scalability and performance, and design high-performance APIs, workflows, and event-driven systems while mentoring teams and guiding projects end-to-end. Key highlights: 1. Developing scalable backend systems with FastAPI, Celery, Redis, AWS Lambda, SQS, and EventBridge, capable of handling thousands of concurrent users efficiently. 2. Building a real-time event-driven campaign and user segmentation system, enabling dynamic targeting and personalized business workflows. 3. Ensuring system reliability and consistency with distributed locking using Redis Redlock, caching, rate limiting, and centralized logging. 4. Leading Oracle to PostgreSQL data migration, creating robust scripts and validation processes to guarantee full data integrity and accuracy. 5. Designing AGS (Auto Gold Save), a subscription-based automated gold purchase system allowing users to set flexible 3, 6, or 12-month plans. 6. Automating dispute handling workflows, securing calculations and resolving user issues without manual intervention. 7. Delivering multiple micro-projects, including a guest-checkout e-commerce platform and an event-based gold gifting system for non-registered users. 8. Managing secure payment. 9. Creating Metabase dashboards for key business metrics, enabling data-driven decision-making across teams. 10. As Tech Lead, mentoring engineers, reviewing code, fostering collaboration, and ensuring adherence to best practices, security standards, and high-quality software delivery. With extensive experience in backend engineering, cloud integrations, and distributed systems, I help businesses transform legacy platforms into modern, reliable, and scalable solutions.

Senior Software Engineer

HeavyTask LLC • Parttime

Apr 2021 - Present • 5 yrs 1 mo

At HeavyTask LLC in Dhaka, Bangladesh, I have been working as a Software Engineer (part-time) since May 2021, focusing on backend development, deployment automation, and building scalable enterprise SaaS platforms. I work extensively with FastAPI, PostgreSQL, Redis, Celery, Docker, and AWS, streamlining CI/CD pipelines, ensuring environment consistency, and implementing production-ready, secure deployments. I contribute to multiple projects, including CRM systems, influencer marketing platforms, legal case management tools, and migration of legacy systems to modern architectures. Key projects and responsibilities: 1. Secret Sauce: Developed the backend for an influencer marketing platform, connecting brands with influencers for promotional campaigns. Integrated external APIs, including Instagram and TikTok, to fetch influencer data. Designed database models and implemented migrations using SQLAlchemy and Alembic. Built automated, secure deployment pipelines using AWS ECR and ECS within a private VPC, ensuring isolated networking, scalability, and production-grade security. 2. Legal Case Management Platform (Docketwise-like): Developed backend APIs for a legal case management system, enabling efficient management of case data and workflows. Implemented secure and automated deployment pipelines, ensuring high reliability for enterprise users. 3. Legacy System Migration: Migrated a legacy Node.js (LoopBack v3) + MongoDB system to a modern FastAPI + PostgreSQL architecture. Ensured complete and accurate data transfer from MongoDB to PostgreSQL through automated migration scripts, maintaining data integrity and consistency. 4. Implemented automated deployments using AWS ECR and ECS, enabling scalable, reliable, production-ready releases.

Senior Software Engineer

A R B R E E S O L U T I O N S • Fulltime

Sep 2021 - Nov 2022 • 1 yr 2 mos

At Arbree Solutions in Dhaka, Bangladesh, I worked as a Software Engineer from October 2021 to November 2022. During this time, I contributed to the development of OTA (Online Travel Agency), CRM, e-commerce, and LMS (Learning Management System) projects, focusing on backend architecture, database design, and payment integration. I implemented scalable and reliable APIs, optimized database queries, and ensured smooth, secure payment processing across multiple platforms. Key highlights of my work include: 1. Developing backend systems using Django, FastAPI, PostgreSQL, and Redis, ensuring performance, maintainability, and scalability. 2. Integrating multiple payment gateways including Bkash, Nagad, Stripe, and PayPal, enabling secure and seamless transactions. 3. Optimizing SQL queries and API performance to improve response times and system reliability. 4. Collaborating with cross-functional teams to gather requirements, design solutions, and implement features efficiently. 5. Maintaining high code quality through code reviews, testing, and adherence to best practices.