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Md. Shamim Molla
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Md. Shamim Molla

Senior Software Engineer (Backend)

Backend engineer with 7+ years building production Java/Spring Boot systems in AdTech, cloud billing, healthcare/pharmacy ERP, e-commerce and fintech.

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  • Java
  • Spring Boot
  • Microservices
  • Kafka
  • AWS
  • SQL & NoSQL
  • Application Security
  • Spring AI / RAG
Portrait of Md. Shamim Molla

Dhaka, Bangladesh

Years experience
7+
Projects
13
Technologies
62+
Companies
2

About

Currently owns 7+ microservices on Improve Digital's AdTech marketplace (Azerion), covering deal management, reporting and security, where I led pentest remediation to certification and cut a third-party sync job from 20 to 6 minutes. In 2025, also built the backend of Multicloud, Azerion's multi-cloud billing platform.

Previously a team lead for 6–10 engineers at Zaag Systems, building pharmacy ERP services that handle about 1M requests a day across 700+ branches. Building a multi-tenant RAG platform with Spring AI and pgvector as a personal project.

Languages:
  • Bangla
  • English
  • Hindi

Core strengths

Java & Spring in production
Spring Boot, MVC, Data JPA/Hibernate and Security across AdTech, ERP, e-commerce and SaaS; Spring Cloud and Spring AI in personal work
Microservices & APIs
10+ production services; REST + OpenAPI/Swagger on every backend project; event-driven design (Kafka, RabbitMQ)
Database design & performance
Data modeling, indexing and query optimization on Redshift tables with 10–20M+ rows; JOIN vs CTE vs view choices; N+1 fixes; Redis caching on million-row tables
Application security
Led pentest remediation to certification; Keycloak SSO (10K+ users); Spring Security, OAuth 2.0, JWT, RBAC, TOTP 2FA, multi-tenant data isolation
AI / RAG
Hybrid vector + full-text retrieval (RRF), grounded answers with citations, outbox-based ingestion pipeline
Quality
Marketplace and Multicloud fully covered by unit and integration tests; JUnit, TDD; CI/CD with Jenkins, GitHub Actions, GitLab CI, TeamCity and Bamboo
Leadership & client delivery
Team lead at Zaag (hired, mentored, reviewed code); turned client specs into production systems for clients in many countries; Agile with Jira and Confluence

Experience

View all experience
  1. Current role

    Senior Software Engineer (L-I → L-II)

    Vivasoft Limited (opens in a new tab)Dhaka
    Client: Azerion (Improve Digital Marketplace, Multicloud) · Promoted to L-II in Jan 2025
    • Own 7+ of 15+ microservices on the Marketplace (Improve Digital's DSP) as part of a 10+ engineer team working directly with Azerion teams in Europe. Main areas: deal management, reporting and security.
    • Led security remediation after a third-party penetration test: fixed every finding, including tenant data isolation, and the platform is now pentest-certified.
    • Cut the TPI third-party sync from 20 to 6 minutes (−70%) by redesigning indexes, tuning queries and running external API calls in parallel with cached tokens.

  2. Software Engineer → Senior Software Engineer

    Zaag Systems Ltd. (opens in a new tab)Dhaka
    Joined as Software Engineer; promoted to Senior
    • Team lead for 6–10 engineers: hired, mentored and reviewed code.
    • Built Spring Boot ERP services for OS Pharmacy (inventory and expiry tracking, POS, accounting) handling about 1M requests a day, with real-time inventory sync across 200+ branches. The system has since grown to 700+ branches and 3,000+ users.
    • Built pharmacy safety features: alerts that flag potentially dangerous drug combinations, and secure handling of patient data.

  3. Junior Software Engineer

    Vivasoft Limited (opens in a new tab)Dhaka
    • Mobile Finance Application (fintech client, name confidential): fixed backend bugs in P2P transfers, statements and account management, and redesigned the whole portal in Thymeleaf.
    • Instorage: built server-side-rendered Next.js frontends for a storage-booking system.
    • PI-CMS: worked on a CMS for React apps (TypeScript, Node.js, GraphQL); left mid-development.

Featured projects

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  • AdTech DSP

    Marketplace

    Vivasoft → Azerion, 2022 – now

    Improve Digital's demand-side platform, giving advertisers a direct, efficient path to premium supply worldwide.

    • Java
    • Spring Boot
    • MariaDB
    • AWS Redshift
    • MongoDB
    • Redis
    • Kafka
    • Keycloak
    • AWS MediaConvert
    • Angular
    Visit site: Marketplace (opens in a new tab)
  • Cloud billing / FinOps

    Multicloud

    Vivasoft → Azerion, 2025

    Azerion's multi-cloud billing platform, a separate product from Marketplace. I built the whole backend: two services that pull cloud billing data together into one portal.

    • Spring Boot
    • Spring Security
    • JWT → SSO
    Visit site: Multicloud (opens in a new tab)
  • AI / knowledge search

    Enterprise RAG Platform

    Personal, MVP, ongoing

    A multi-tenant Retrieval-Augmented Generation platform built as Spring microservices.

    • Java 25
    • Spring Boot 4.1
    • Spring AI 2.0
    • pgvector
    • RabbitMQ
    • React 19
  • Pharmacy ERP

    OS Pharmacy

    Zaag, 2019 – 2022

    Pharmacy ERP for pharmacies across Bangladesh: inventory and expiry tracking, POS, sales, expenses and per-user accounting.

    • Java
    • Spring Boot
    • MongoDB
    • React
    • Flutter
    Visit site: OS Pharmacy (opens in a new tab)
  • Medicine delivery

    Oushod Sheba

    Zaag, 2019 – 2022

    Online medicine, health and beauty delivery service in Bangladesh, on web (Next.js SSR) and mobile (Flutter), with a React admin portal.

    • Spring Boot
    • MySQL
    • MongoDB
    • Redis
    • Next.js
    • React
    • Flutter
    Visit site: Oushod Sheba (opens in a new tab)
  • Food service

    Restaurant Management System

    Zaag

    Daily sales, purchasing, stock tracking, kitchen-screen workflows and fast billing.

    • Spring Boot
    • MySQL
    • React
    • Docker
    • AWS

Skills

Languages, frameworks, messaging, data stores, cloud and tooling used in production.

Languages4 skills
Java · SQL · JavaScript (ES6+) · TypeScript
Backend7 skills
Spring Boot · Spring MVC · Spring Data JPA / Hibernate (incl. Envers, Vector) · Spring Security · Spring Cloud Gateway & Config · Spring AI · Node.js (Express)
APIs & Integration4 skills
REST · OpenAPI/Swagger (springdoc) · Keycloak · AWS MediaConvert
Security6 skills
OAuth 2.0 · SSO (Keycloak) · JWT (access/refresh) · RBAC · TOTP 2FA · Multi-tenant isolation
Messaging & Events3 skills
Apache Kafka · RabbitMQ (transactional outbox) · Event-driven development
Databases & Caching7 skills
MySQL · PostgreSQL (pgvector, full-text search) · MariaDB · MongoDB · AWS Redshift · Redis · Memcached
AI / RAG8 skills
Spring AI · OpenAI chat & embedding models · pgvector · Hybrid search (RRF) · Apache Tika · PDFBox · POI · JTokkit
Cloud & DevOps5 skills
AWS (ECS, Lambda, S3, RDS, Redshift, SQS, CloudFront and more) · Docker · Docker Compose · MinIO · Multi-cloud billing data (AWS, GCP, Huawei Cloud)
CI/CD5 skills
Jenkins · GitHub Actions · GitLab CI · TeamCity · Bamboo
Testing4 skills
JUnit · Unit & integration testing · TDD · Postman
Frontend4 skills
React · Next.js (SSR) · TypeScript · Thymeleaf
Tools7 skills
Git · Maven · Gradle · Flyway & Liquibase (DB migrations) · Jira · Confluence · Agile/Scrum

Credentials

Education

Problem Solving & Certifications

Active competitive programmer focused on data structures and algorithms.

3 profiles

Contact

Current availability

Remote or relocation, any country, any role type

Location: Dhaka, Bangladesh

mdshamim723@gmail.com