Tuan Doan

Software Developer

Ho Chi Minh City, Viet Nam

Summary

I'm a backend developer with a focus on Python and building clean, scalable systems. I care about writing readable code, designing efficient APIs, and always improving the tools we rely on.

Outside of work, I write and direct independent films — a creative practice that sharpens my storytelling instincts and attention to detail. Whether it's code or cinema, I'm drawn to structure, meaning, and impact.

Languages:

English, Vietnamese

Favorite Python Packages:

pytest, django, request, opencv, pygame, unitest, sys

Experience

Backend Engineer, JULO (www.julo.co.id)

Jan 2024 - Present

Tech Stack: Django, Python, Celery, PostgreSQL, Redis, RabbitMQ, Docker, AWS, Black, isort, Flynt, Sentry, Datadog

Key Responsibilities & Achievements:
- Designed RESTful APIs and maintained scalable backend services using Django, Celery, Redis, RabbitMQ, and PostgreSQL
- Monitored system health and performance via Sentry, Datadog, and Grafana
- Followed Scrum methodology and collaborated cross-functionally with product and QA teams

Notable Projects:
- Development Tools Improvement: Enhanced developer productivity and code consistency by introducing pre-commit hooks using Black, isort, and flake8.
- Flake8 Upgrade Strategy: Upgraded legacy flake8 2.5 to 4.0 in a large monorepo. Introduced a transitional CI job to let teams gradually opt in by registering their subapps, ensuring backward compatibility and minimizing disruption.
- QRIS Loan Integration (Amar Bank): Built a system to enable users to scan QR codes and make loans via integration with Amar Bank, allowing instant bank account top-ups
- Fraud Control Mechanism: Collaborated with the data team to implement a feature that limits loan amounts for users flagged as potentially fraudulent or abusive

 

Software Engineer, GSI (www.gsi-group.asia)

July 2023 - January 2024

Tech Stack: Python, Django, Flask, FastAPI, React, JavaScript, Docker, GitLab CI, Selenium, OpenAI API, Ansible, Prometheus, Grafana, SonarQube, Agile/Scrum, Linux

Key Responsibilities & Achievements:
- Developed and maintained internal tools using Python, Django, Flask, FastAPI.
- Built and maintained CI/CD pipelines using GitLab CI, Docker, and Container Registry
- Wrote and maintained some end-to-end tests using Selenium
- Developed monitoring and alerting systems using Prometheus and Grafana
Worked closely with German engineering managers to resolve technical challenges and improve system reliability
- Mentored junior developers in CI/CD workflows and deployment best practices

Notable Projects:
- PDF Checker: Created a prototype web app to detect misspellings and translate PDF text using OpenAI APIs
- Geo-technical Solutions Migration: Helped rebuild the backend and wrote E2E tests while modernizing an existing PHP-based application
- GitLab–Bitbucket Sync Tool: Built a system for synchronizing repositories between GitLab and Bitbucket
- CI/CD for Internal Projects: Set up GitLab CI/CD pipelines for internal apps like ALLPLAN, enhancing deployment speed and reliability.

 

Founder, Rain Rain Film Festival (www.rainrainfilm.com)

August 2023 - Present

A local film festival platform I created to support independent filmmakers and encourage the growth of small-scale film festivals in Vietnam. The festival's last edition was in 2024.

Tech Stack: Django, JavaScript, HTML, CSS, GitHub Workflows, Ansible, DreamHost, DigitalOcean

Key Responsibilities & Achievements:
- Established festival goals, drafted regulations, and managed event organization
- Developed and deployed the full website stack using Django, JavaScript, CSS, and HTML
- Deployed the app on DigitalOcean, with domain and email hosted via DreamHost
- Implemented CI/CD pipelines using GitHub Workflows and Ansible for smooth deployment
- Designed and built a responsive front-end to ensure cross-device accessibility

Notable Features:
- Audience Voting System: Festival attendees receive a unique token at the event to vote for their favorite film online
- Blog Engine: Admins can write and publish festival blog posts using Markdown syntax

 

Backend Engineer, JULO (www.julo.co.id)

August 2021 - October 2022

Technologies: Django, Javascript, Celery, Redis, PostgreSQL, Docker, Sentry, Datadog, Grafana, ELK, AWS, Scrum

Notable Projects:
- Customer Facing Score (CFS): Developed logic to track user behavior and reward points, which could be converted into cashback
- Cashback Overpayment: Built a feature to detect overpaid loan amounts and credit them back as in-app cashback
- iPrice Integration: Integrated with iPrice (Indonesian e-commerce) to allow users to use JULO loans for purchasing products
- Julover Program: Implemented backend flow for employee-exclusive customers eligible for special interest discounts
- Slack Automation for Monitoring: Created a daily scheduled system to pull and format Sentry errors into Slack for improved alert visibility and faster debugging

Skills

Backend Development, Celery, DevOps, Django, Django REST Framework, Docker, FastAPI, Git, Google Cloud Platform (GCP), Gunicorn, JavaScript, Jenkins, Linux, PostgreSQL, PyQt, REST, Redis, SQL, Test-Driven Development, Virtualenv, Web Development