Hey, I'm

NGUYEN TRONG HAI

But you can call meHai

I'm a Software Engineer, Full-stack Developer & Technical Lead

Nguyễn Trọng Hải

About

A concise overview of my experience, working principles, and strengths.

I'm a Web Engineer with over 5 years of experience turning complex business requirements into user-focused digital solutions. I collaborate closely with cross-functional teams to deliver fast, reliable, and maintainable products.
My core strengths include website performance optimization, RESTful API design, and seamless system integration. I'm passionate about improving development workflows and staying current with modern web technologies.
Although I graduated in Thermal Engineering, that background built a strong foundation in logical reasoning and problem-solving—skills that have been crucial to my success as a software developer.

Key highlights:
• 5+ years of experience, 10+ production projects (small to large scale)
• Performance: improved TTFB and response time by 30–50% across multiple projects
• CI/CD: reduced release time by ~60%, increased deployment stability
• Reliability: maintained service uptime up to 99.9% depending on project

Skills

Technologies I master to build reliable, performant, and scalable systems.

Backend

Django, FastAPI, Laravel

Frontend

Next.js, ReactJS

Database

PostgreSQL, MySQL

DevOps

AWS, Jenkins, Docker

Featured Projects

Selected products where I played a key role.

Yadoriki Change thumbnail

Yadoriki Change

Developed a robust automation framework using Playwright and Celery to synchronize hotel data between customer websites and major Japanese hotel management platforms such as TL Lincoln and Neppan.

Technical Approach:
• Built a modular automation system leveraging Playwright to simulate native user interactions on each platform, ensuring compatibility with frequently changing UI structures.
• Integrated API-based data processing and Celery task queues to handle high-volume synchronization jobs asynchronously, enabling scalability and fault tolerance.
• Designed a reusable synchronization framework allowing flexible configuration for multiple clients and hotel systems — rather than isolated one-off bots.

Key achievements:

• Unified data mapping layer to standardize communication between local sources and external hotel systems.
• Intelligent retry and error-handling pipeline with centralized logging and monitoring.
• Optimized queue scheduling to minimize synchronization latency and balance workload dynamically.

Role: Lead Backend — System Architecture, Code Review, and Deployment Automation.

Outcome:
• Achieved ~99% synchronization accuracy, reducing manual input errors by 80%.
• Increased throughput and stability of data updates across multiple platforms.
• The developed framework shortened development time for new hotel connectors by over 50%.

PythonDjangoPlaywrightPostgreSQLJenkins
Resunasu thumbnail

Resunasu

Developed a web application that enables healthcare providers to create, manage, and send medical surveys directly through LINE, with integrated contact management and payment processing.

Technical Approach:
• Designed a secure and scalable backend architecture, ensuring compliance with data protection standards for sensitive medical information.
• Integrated LINE Messaging API for automated survey delivery and response tracking.
• Implemented Google Place API for clinic data validation and Stripe for seamless online payments.
• Focused on performance, reliability, and maintainability through modular design and comprehensive unit testing.

Key achievements:

• Built a scalable, maintainable codebase
• Optimized performance and reliability through unit tests
• Successfully integrated with LINE API, Google Place API, and Stripe

Role: Backend Developer, API Architecture, Payment Integrations

Outcome:
• Reduced average survey sending time by 40%, improving operational efficiency.
• Increased user response and completion rates by 25% thanks to smoother delivery and UX.
• Built a solid foundation for future multi-channel survey distribution.

PythonDjangoPostgreSQLLINE APIStripe APIGoogle API
Yadoriki Crawl thumbnail

Yadoriki Crawl

Developed a large-scale crawler system to extract and aggregate hotel data from major Japanese booking platforms. The system processed, normalized, and visualized data to support business analysis and strategic decision-making.

Technical Approach:
• Designed and implemented a modular crawling and ETL pipeline capable of handling millions of records monthly.
• Built data normalization workflows to unify structures from diverse sources, ensuring clean and analyzable datasets.
• Deployed and maintained AWS-based infrastructure, optimizing compute and storage utilization for scalability and cost efficiency.
• Implemented monitoring, retry, and scheduling mechanisms for reliable, fault-tolerant operation.

Key achievements:

Built a reliable, scalable data aggregation system
• Demonstrated strong skills in processing and structuring large datasets
• Designed and deployed infrastructure on AWS

Role: Data Engineer — Crawler Architecture, ETL Pipeline Design, AWS Infrastructure.

Outcome:
• Collected and processed 1M+ hotel records per month.
• Reduced infrastructure costs by approximately 35% through optimized resource usage.
• Improved data accuracy and availability for downstream analytics systems.

PythonDjangoSeleniumAWS ECSRDS AuroraJenkins
Mental Health EHR System thumbnail

Mental Health EHR System

Developed a dedicated Electronic Health Record (EHR) platform tailored for mental health clinics, streamlining the entire patient care workflow — from examination and diagnosis to treatment and progress monitoring.

Technical Approach:
• Designed and implemented a secure, role-based access control system with detailed audit trails to ensure compliance with medical data privacy and healthcare regulations.
• Built comprehensive modules for clinical documentation, appointment management, therapy tracking, and real-time patient monitoring with intelligent alerting.
• Applied the Bmad Method for full lifecycle delivery — from requirement analysis and UI/UX design to backend development, deployment, and maintenance.
• Automated infrastructure and CI/CD pipelines to ensure reliable updates and system scalability.

Key achievements:

• Solo full-stack development using Bmad Method for complete project lifecycle
• Designed secure EHR system with role-based access control and audit trails
• Implemented real-time patient monitoring and alert system

Role: Solo Full-Stack Developer — Product Owner, UX/UI Designer, DevOps Engineer.

Outcome:
• Reduced patient data processing time by 70%, significantly improving operational efficiency.
• Increased treatment accuracy and consistency by 40% through structured, accessible patient data and clinical insights.
• Provided a foundation for digital transformation in small-to-medium mental health facilities.

PythonFastAPIReact.jsPostgreSQLDockerAWSBmad Method
Photo/Video Editing Service Platform thumbnail

Photo/Video Editing Service Platform

• Built a professional photo/video editing service promotion platform.
• Multi-role CMS system: customer registration/ordering, admin management, staff task assignment.
• Integrated PayPal payment gateway with complete workflow management from order to delivery.

Key achievements:

• Built a multi-role CMS system featuring customer registration, order submission, admin management, and staff task assignment.
• Integrated PayPal payment gateway with a fully automated workflow covering order confirmation, payment tracking, and delivery notifications.
• Designed intuitive UI/UX flows to simplify service selection, pricing, and communication between customers and editors.
• Deployed a scalable full-stack architecture with monitoring, CI/CD, and security best practices for reliability and maintainability.

Role: Solo Full-Stack Developer, Product Owner, UX/UI Designer, DevOps Engineer

Outcome:
• Streamlined order processing by 80%, reducing manual coordination and turnaround time.
• Increased customer satisfaction by 60% through smoother interactions and transparent progress tracking.
• Established a solid foundation for scaling the business into multi-service digital production.

PythonFastAPIReact.jsPostgreSQLPayPal APIDockerAWSBmad Method
Korean E-commerce Platform thumbnail

Korean Community E-commerce Platform

Developed an e-commerce platform designed to connect members of the Korean community, enabling users to buy, sell, and exchange goods or services in a trusted social environment.

Technical Approach:
• Implemented a robust backend architecture with modular APIs for product listings, transactions, messaging, and user management.
• Integrated a secure payment system, comprehensive order management, and social interaction features such as user reviews and community discussions.
Designed and optimized database schemas for scalability and fast query performance under growing user activity.

Key achievements:

• Built a reliable and scalable API layer to support real-time interactions.
• Implemented advanced caching and indexing strategies to boost data access speed.
• Established CI/CD pipelines and monitoring tools to improve deployment stability.

Role: Backend Developer, API Architecture, Database Design

Outcome:
• Improved overall platform performance by 65%, significantly enhancing user experience and engagement.
• Reduced API response time by 50%, significantly enhancing user experience and engagement.

PHPLaravelMySQLRESTful APIJWTRedisDocker

Work Experience

My career journey, responsibilities, and impact created.

1

Software Engineer

Inisoft JSC | 08/2024 - Present

Serving as PM and Team Leader, managing projects and leading development teams. Planning, task assignment, and ensuring product quality.

2

Software Engineer

Landbridge JSC | 08/2023 - 08/2024

Led core web app development, collaborated cross-functionally, and mentored junior engineers.

3

Software Engineer

AMELA Technology JSC | 04/2021 - 08/2023

Designed backend architecture, implemented CI/CD and automated testing to improve code quality and development velocity.

4

Frontend Developer

Hung Ha Payment JSC | 03/2020 - 04/2021

Built responsive, high-performance UIs with a strong focus on UX.

Contact

If you have a project or need an expert, feel free to reach out.

I typically respond within 24 business hours.

(+84) 844 463 636
Từ Liêm, Hà Nội