m
mahathirdev

Mahathir

@mahathirdev

Backend Engineer

Bangladesh
Bengali, Inglês, Hindi
Algumas informações são exibidas no idioma inglês.
Sobre mim
Backend engineer with 3+ years building production Java and Spring Boot systems for fintech, telecom and ERP companies. I mostly fix and extend existing backends: broken REST and GraphQL APIs, JPA/Hibernate mapping errors, slow PostgreSQL and MySQL queries, transaction bugs, Kafka consumers, and Docker deployment failures. I will tell you honestly if I cannot solve your problem, and I do not disappear mid-project. Send me your error message or repo link and I will tell you what is wrong before you order.... Saiba mais

Habilidades

m
mahathirdev
Mahathir
offline • 

Conheça meus serviços

Correções de bugs
I will fix bugs and errors in your java spring boot backend
A partir deUS$ 25 /projetoMais detalhes

Experiência profissional

One_Direction Companies Limited

Software Engineer

One Direction Companies Limited • Período integral

Jan 2026 - Present • 9 mos

Building backend microservices for a large-scale ERP/POS platform. - Design and build GraphQL and REST APIs with clean service boundaries - Set up MinIO as self-hosted S3-compatible object storage with pre-signed URL access - Deploy services to Linux production servers using Docker and Terraform - Use Kafka for asynchronous communication between services - Review code and mentor newer team members Stack: Java, Spring Boot, GraphQL, PostgreSQL, Kafka, MinIO, Docker, Terraform, Linux

Telcobright_Limited

Software Engineer

Telcobright Limited • Período integral

May 2023 - Jan 2026 • 2 yrs 8 mos

Built high-throughput backend systems for telecom billing and payments. - Architected an in-memory caching library with a Write-Ahead Log handling 10,000+ transactions per second with zero data loss - Built a real-time VoIP billing platform processing 1.5M+ calls per month at 99.9% uptime, including JWT auth, REST APIs, balance validation and fractional refunds - Designed event-driven call event persistence and automated CDR generation using Kafka - Built a CDR analysis system processing 20M+ records daily with 100% billing accuracy Stack: Java 21, Spring Boot, Quarkus, Kafka, MySQL, Docker, FreeSWITCH