Software Engineer

Tahsin Ahmed
Majumder

Building scalable backend systems for European public transportation. Experienced with Node.js, Go, Python, and cloud-native architectures.

View Experience See Projects
Tahsin Ahmed Majumder

About Me

Software Engineer at WellDev, specializing in backend systems for European public transportation platforms. Currently building data pipelines and driver management tools for clients like DVB and AAGL through the Innotix platform.

Experienced in Node.js, ColdFusion, Go, and Python with a strong foundation in ETL pipelines, multi-tenant architectures, and real-time data processing. Passionate about clean code, mentoring, and solving complex engineering challenges at scale.

B.Sc. in Computer Science & Engineering from Chittagong University of Engineering & Technology. Solved 600+ competitive programming problems across Codeforces, LeetCode, and HackerRank.

Location

Dhaka, Bangladesh

Email

tahsinbd.ahmed1@gmail.com
LinkedIn GitHub

Technical Skills

Languages

C++ Golang Python Node.js Ruby ColdFusion HTML/CSS SQL

Frameworks & Databases

ExpressJS Rails ColdBox PostgreSQL MySQL MariaDB MongoDB

Developer Tools

Git GitHub Docker Bash Postman VS Code

Professional Experience

WellDev | Node.js

July 2025 - Present

Software Engineer L2

  • Developed an Interface Service to ingest and process GIS-based Light Signal Adapter data streamed via MQTT for DVB (Dresdner Verkehrsbetriebe AG), applied ETL transformations with a custom queuing and batch ingestion mechanism, and delivered the processed data to the driver's mobile application Innotix öV-Pad
  • Developed a service integrating with the DiLoc interface to ingest train location and timetable data, process it via an ETL pipeline, and deliver it to the driver's mobile application Innotix öV-Pad
  • Developed backend services for the Innotix Hirsch driver platform used by AAGL, supporting duty management, extra work reporting, automated payment calculations, leave management, and real-time notifications
  • Contributed to a genetic algorithm–based scheduling system within Innotix Hirsch that autonomously generates and assigns optimal driver duty schedules, improving operational efficiency and resource utilization for AAGL

WellDev | Node.js, ColdFusion

March 2024 - June 2025

Junior Software Engineer L1

  • Engineered and maintained backend infrastructure for InnoTix's Electronic Driver Bag platform, supporting a complex 500K LOC multi-tenant codebase that serves 42+ European public transportation clients across bus, train, and tram sectors
  • Resolved 20+ high-priority SLA-bound bugs through proactive cross-team collaboration, while actively developing shell scripts, documentation, and IDE code snippets to automate development activities
  • Migrated password algorithm from md5 hash to Bcrypt hash to improve security
  • Mentored trainees within the development team, guiding them through projects and debugging techniques
  • Participated in interview panels for new trainee selections, contributing to the hiring process
  • Orchestrated knowledge transfer sessions and developed comprehensive documentation to facilitate smooth onboarding and legacy system knowledge preservation

Brain Station 23 | .NET, EF Core

July 2022 - October 2022

Trainee Software Engineer

  • Explored the nopCommerce codebase to understand template and plugin development processes
  • Assisted in the development of templates and plugins for nopCommerce, worked with .NET Core and Entity Framework

Projects

Real Estate Property Investment Analysis

Flask, scikit-learn, XGBoost, NLTK, spaCy, Transformers

  • Scores properties based on their flipping potential using trained models and NLP analysis to predict resale values and renovation costs
  • Visualizes properties on an interactive map with color-coded grades along with property filters such as price, bedrooms, bathrooms, ROI, and more
  • Compares multiple ML algorithms (Linear Regression, Random Forest, Gradient Boosting, XGBoost) and selects the best performer for each prediction task
  • Performs sentiment analysis on property descriptions using transformer models and extracts renovation levels to drive risk assessment and grade assignment
GitHub →

Short Term Rental System

FastAPI, Supabase

  • Implemented high-performance data loading in Supabase
  • Solved critical N+1 performance bottleneck in property scoring by implementing batch fetching and bulk upsert operations
  • Designed and implemented an 8-component weighted scoring system for evaluating STR investment opportunities
  • Frontend and backend containerised as separate services, deployed on Render
GitHub → Live Demo →

⚠ On Render (cold start) — visit the backend first to wake it up, then open the demo.

Integration Gateway

Go, PostgreSQL

  • Designed layered microservice architecture with REST API, batch worker pool, and health check endpoints
  • Implemented production-grade resilience patterns including circuit breakers, exponential backoff retry, and token bucket rate limiting
  • Built multi-source data orchestrator supporting concurrent JSON/XML external API calls with idempotency via database constraints
  • Containerised application and mock services with fault injection for chaos testing, orchestrated via Docker Compose
GitHub →

Education & Achievements

Chittagong University of Engineering & Technology

B.Sc. in Computer Science & Engineering

2018 - 2023

Grade: 3.05 / 4.00

Competitive Programming

Solved 600+ problems across online judges

StopStalk LeetCode