Tung Nguyen Duy — Curriculum Vitae

Professional Summary

Full-stack Software Engineer, nearly 3 years shipping production web applications for international clients, fully remote. Backend-focused: Ruby on Rails, Laravel, NestJS, Java/Spring Boot, PostgreSQL, MySQL, TypeScript, React, Vue. Most of my work is backend: building and maintaining features in long-running production systems, optimising slow queries and page loads once real data arrives, and owning the CI/CD and deployment pipelines my team ships through. Open to contract or full-time remote roles, async and writing-first. Based in GMT+7 — full overlap with European business hours, and up to four hours with US Eastern.

Work Experience

MOOBON, Inc.Jun 2024 – Present

Software Engineer · Remote, Full-time corporate.moobon.jp

Project: EcologynetAug 2024 – Present

Software Engineer · Team size 5 · Detailed design, development, unit & integration test, operation, maintenance

A waste management platform for Japanese companies, supporting contracts, licenses, treatment processes, electronic manifests, and compliance reports. My primary project since joining, and the one I have contributed the largest share of code to.

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Maintained JWNET integration, including EDI request files, result processing, progress-date change tracking, status synchronization, and error handling.
Implemented authentication, email-based two-factor authentication, and hierarchical access control across a multi-tenant user base.
Implemented business logic and validations for waste manifests, contracts, licenses, treatment processes, and schedules.
Developed scheduled jobs for automatic manifest generation, deadline notifications, and daily cleanup batches.
Implemented high-performance CSV and PDF export for compliance reports and electronic manifests.
Developed and maintained features across the Provider, Client, and Operation portals.
Conducted source code reviews, enforced coding standards, and ensured reliability through bug investigation and testing.
Managed Docker-based local development environments and supported CI/CD workflows for seamless deployment.

Environment: Ruby 3.2, Ruby on Rails 7.2, MySQL 8, Redis, HAML/SCSS, JavaScript/Stimulus/Turbo, Bootstrap 5, RSpec/RuboCop/Brakeman, Git/GitHub Actions, Docker Compose, AWS S3/ECR/ECS Fargate, Sentry, PaperTrail, JWNET/EDI/CSV/FTP

Learnings: Japanese waste-management and electronic-manifest domains; designing complex business rules in a large Rails application; asynchronous integration with legacy systems; data isolation and hierarchical authorization in a multi-tenant system; idempotent, duplicate-safe batch processing; query and report optimization for large datasets.

Project: Glass MemberJun 2024 – Jul 2026

Software Engineer · Team size 5 · Development, migration, testing, deployment, operation, maintenance

A membership management platform for a Japanese eyewear industry association, managing members, stores, payments, training, Prime accreditation, and administrative workflows. I led the migration from hand-managed EC2 hosting to a containerized architecture.

Containerized a legacy Ruby on Rails application with Docker and migrated it from direct EC2 hosting to Amazon ECS on EC2.
Provisioned the full production stack — ECS, ECR, ALB, Auto Scaling, launch templates, IAM roles, SSM, and CloudWatch — as Terraform code with an S3 remote backend.
Built GitHub Actions pipelines for Docker image builds, ECR pushes, and ECS deployments.
Configured ECS scheduled tasks for member email notifications, and created CloudWatch Logs Insights dashboards and saved queries to monitor traffic by functional route.
Developed Prime accreditation history, admin management screens, a data-backfill rake task, CSV export, and payment logic.

Environment: Ruby 3.1.2, Rails 7, MySQL 8, Haml, JavaScript, Bootstrap 5, Docker Compose, Terraform, AWS EC2/ECS/ECR/ALB/Auto Scaling/S3/SSM/CloudWatch, Git/GitHub Actions

Learnings: Maintaining and modernizing a legacy Rails application; owning a production migration from EC2 to ECS on EC2; expressing a whole environment as reviewable Terraform code.

Project: Adidas mi-uniformNov 2025 – Aug 2026

Software Engineer · Team size 8 · Development, unit & integration test, maintenance · mi-uniform.adidas.jp

A B2B platform for the Japanese market supporting sports-uniform customization, quotations, pre-orders, production, and delivery management. The system consists of a public product simulator and a role-based CMS for Adidas staff, retailers, and suppliers.

Developed and maintained order-management features across the Adidas/Maker, retailer, and supplier portals, covering creation, editing, duplication, appended orders, cancellation, status tracking, and order summaries.
Implemented multi-order PDF export and technical-document generation driven by Headless Chromium.
Extended the SVG-based uniform simulator: part sorting and validation, colour-palette interaction, NG-colour rules, product switching, product-code and branch-number lookup, and customized-image download.
Built product search and filtering, VAS master management, and a font master screen; scheduled the daily SAP customer-master import that keeps the CMS in sync.
Hardened order data entry — shipping-address validation, split recipient-name fields with character limits, waybill and PO number handling, and estimated delivery dates surfaced through to the PDF output.
Reviewed code, investigated business-flow defects, and improved frontend/backend maintainability across a shared-database, multi-application architecture.

Environment: PHP 8.2+, Laravel 12, Vue 3, Inertia.js, Blade, JavaScript, HTML/SCSS, Vite, MySQL 8, Redis 7, Eloquent ORM, Axios, Headless Chromium, SFTP/SAP, Docker Compose, Nginx, Git/GitHub, PHPUnit

Learnings: Sports-uniform customization, pre-order, production, and delivery workflows; role-based workflows shared across Adidas staff, retailers, and suppliers; interactive SVG customization with synchronized UI state; PDF and technical-document generation with Headless Chromium; maintainability in a multi-application, shared-database architecture.

Rikkeisoft Co., Ltd.Feb 2023 – Jun 2023

Backend Developer · Internship, Part-time rikkeisoft.com

Project: CanbusFeb 2023 – Jun 2023

Backend Developer · Team size ~40 · Development, test, maintenance

A low-code enterprise management platform (canbus.com).

Developed APIs and new features for the Canbus platform within Agile sprints.
Collaborated with the QA team to reproduce, investigate, and fix application bugs.
Reported project progress and confirmed task requirements directly with Japanese clients.

Environment: Java, Spring Boot, Docker, JavaScript, Backbone.js, MongoDB

Learnings: Practical experience in Agile software development; Japanese business communication (Ho-Ren-So: Report, Contact, Consult) through direct client interaction.

Personal Projects

PDFlexJun 2025 – Aug 2026

Bilingual PDF Reader with OCR and Document AI · pdflexai.com

A web application for reading PDFs side by side with their translation while preserving the original page layout, with OCR for scanned documents and an AI assistant that answers questions grounded in the document being read.

Designed and built the full stack — Next.js frontend, NestJS API, PostgreSQL, and an OCR service — deployed with Docker Compose behind Nginx.
Built the layout-preserving translation pipeline: text extraction, paragraph grouping and merging, batched translation with retry, and per-page rendering so the translated page mirrors the original.
Implemented OCR for scanned pages, streamed AI translation with live progress and cancellation, and background image translation.
Implemented document chat over Server-Sent Events with attachments, persisted history, Mermaid diagram rendering, and model selection.
Added permissioned share links, page-range export, authentication with GitHub OAuth, and multilingual UI.
Closed a set of access-control gaps — switched document ids to UUIDv7 to stop enumeration of unowned temporary documents, moved page images behind authorized routes with proper ETag caching, and made a missing service secret fail startup rather than open internal endpoints.
Moved production schema onto TypeORM migrations and set up a GitHub Actions deployment pipeline.

Highlights: Translation that keeps the page intact instead of flattening it to text; a security pass that turned three quiet access-control gaps into closed doors.

Environment: Next.js, React, Redux Toolkit, Tailwind CSS, NestJS, TypeORM, PostgreSQL, Google Cloud Translate, OCR, sharp, pdf-lib, NextAuth, Server-Sent Events, Docker Compose, Nginx, GitHub Actions

SayvelaMar 2026 – Aug 2026

Multilingual Meeting AI Assistant · github.com/tungnguyensnk/sayvela

A desktop application for multilingual meetings, featuring real-time, cross-lingual speech-to-speech translation (a user speaks in Language A while listeners instantly hear Language B), alongside text-to-speech and integrated AI assistance.

Designed and developed the architecture spanning the Tauri/Rust desktop client, Next.js web app, and NestJS backend.
Engineered the real-time speech-to-speech pipeline, handling live transcription and instantaneous cross-lingual audio delivery over WebSockets.
Integrated Soniox transcription and text-to-speech with secure API-key storage, and reworked the Rust audio channels to keep the stream from stalling when idle.
Implemented JWT authentication, session history, transcript grouping, and Stripe-based subscription billing.

Highlights: Near-instantaneous cross-lingual communication by combining Rust (Tauri) with a Next.js front end; low-latency audio and data streaming over WebSockets.

Environment: React, Next.js, Tauri, Rust, NestJS, PostgreSQL, Drizzle ORM, WebSocket, Soniox, Stripe, Docker, Nginx

KumoApr 2026 – Jul 2026

Remote AI Coding Companion & CLI Platform · github.com/tungnguyensnk/kumo

A mobile companion and CLI platform for remotely controlling Claude CLI and Codex CLI, managing coding sessions, and previewing local web applications directly from Android devices.

Developed the end-to-end ecosystem, including the Android mobile application, backend API, and desktop CLI published to npm.
Built real-time interaction features for AI CLI chat, workspace and terminal management, source file editing, rollback, and image attachments.
Engineered HTTP tunneling and port forwarding over WebSockets, allowing local development servers to be securely previewed on mobile devices.
Implemented secure device pairing, JWT authentication, Redis-based message routing, Android system overlays, and push notifications.

Highlights: Custom HTTP tunneling and port forwarding over WebSockets; real-time synchronization between local node-pty terminals and the mobile interface.

Environment: Flutter, Dart, Kotlin, TypeScript, Node.js, NestJS, PostgreSQL, Drizzle ORM, Redis, WebSocket, Docker, Claude CLI, Codex CLI, node-pty

Kumo BunpouAug 2026 – Present

Japanese Grammar Trainer with Spaced Repetition · github.com/tungnguyensnk/kumo_bunpou

An Android application for learning JLPT N5/N4 grammar from the Minna no Nihongo curriculum, scheduled with FSRS-6 spaced repetition and timed reminders that fire when a grammar point is about to be forgotten.

Built the Flutter application and the NestJS/Prisma backend, from data model through release automation.
Implemented the spaced-repetition core on FSRS-6, including a five-level memory scale derived from card stability, relearning flow, leech detection, and daily study targets.
Generated four exercise types from the curated content set — cloze, multiple choice, sentence scramble, and typing with romaji input accepted.
Implemented timezone-aware local notifications resolved natively, so reminders stay correct as the learner travels.
Built an idempotent content import pipeline keyed on a source hash, covering 100+ N5/N4 lessons, plus a furigana parser and renderer kept separate from the sentence text used for grading.
Set up GitHub Actions CI and automated Google Play publishing, with privacy-policy and account-deletion pages served for store compliance.

Highlights: A documented SRS core — states, memory levels, and interval tables derived from the real scheduler parameters rather than guessed at.

Environment: Flutter, Dart, Riverpod, go_router, Dio, flutter_local_notifications, NestJS, Prisma 7, PostgreSQL, ts-fsrs (FSRS-6), JWT, Docker Compose, GitHub Actions, Google Play

Education & Certifications

Hanoi University of Science and Technology2019 – 2024

HEDSPI — Vietnam–Japan ICT Engineer Program (IT-E6), Information TechnologyTechnical GPA 3.58 / 4.0

Fundamental Information Technology Engineer Examination (FE)Apr 2023

Information-technology Promotion Agency (IPA), Japan

Knowledge & Skills

ProgrammingRuby, PHP, TypeScript, JavaScript, Java, Dart, Rust, SQL BackendRuby on Rails, Laravel, NestJS, Node.js, Express.js, Spring Boot Frontend & MobileReact, Next.js, Vue 3, Inertia.js, Hotwire/Stimulus, Flutter, Tauri Databases & ORMPostgreSQL, MySQL, MongoDB, Redis, ActiveRecord, Eloquent, Prisma, TypeORM, Drizzle Cloud & DevOpsAWS (ECS, ECR, ALB, S3, CloudWatch), Terraform, Docker, GitHub Actions, Nginx, Linux Testing & QualityRSpec, PHPUnit, Jest, RuboCop, Brakeman, Sentry Languages

English — Conversational (written English is the daily working language in a fully remote team)

Japanese — Conversational (two years delivering projects for Japanese clients)

Vietnamese — Native

Personal Statement

I gravitate to the parts of a system that are hard to see: a query plan that degrades only once production data grows, a defect that reproduces at one client and nowhere else, infrastructure that has quietly drifted from how it is documented. Day to day that means backend work: business rules in applications that have been alive for years, queries and reports that need to stay fast as the data grows, and the CI/CD and deployment pipelines the rest of the team ships through. Backend and infrastructure are where I want to keep going deeper.

I have worked fully remotely for nearly three years across a time-zone gap with Japanese clients, which taught me to write decisions down, raise blockers before they become delays, and leave a trail someone else can follow. Outside client work I ship my own products end to end — a bilingual PDF reader, a mobile companion for AI coding sessions — where I own the architecture, the deployment, and the security review rather than only reviewing someone else's.