Slideshow 1: Duc Dao
Duc DaoFull-stack Developer

Built to standard, stable, AI-optimized.

Full-stack developer with 4+ years on Node.js, TypeScript, PostgreSQL, Redis, Elasticsearch, Directus (headless CMS), Vue.js, and Next.js. Works with AI agents Claude, Codex, and Grok: sets up the harness that automates the workflow, then supervises the agents as they work.

Selected work

2024 - Present

1.Adaptably

Project details:

EdTech / Learning Centre Management

Learning platform for the Grade Solution learning centre: students work through exercises matched to their level, earn reward points, and redeem them. AI is built into the app for marking, handwriting OCR, oral exam scoring, and a chat on learning progress for students and parents.

Technologies

  • Vue.js
  • TypeScript
  • Node.js
  • Directus
  • PostgreSQL
  • Redis
  • OpenAI API
  • Claude
  • Grok

Full-stack Engineer

About 3,000 users, 800 of them active regularly. AI runs both inside the product and in how it is built and operated.

Achievements

  • Integrated AI marking for over 1,000 worksheets a month, with a pre-check that drops empty, junk, and copied answers before any LLM call; teachers review only disputed marks, so results arrive far sooner.
  • Gave each AI feature (marking, OCR, oral exam scoring, chat) its own model and harness to keep cost down.
  • Developed with a multi-agent setup: Claude as the lead agent orchestrating Codex and Grok as sub-agents, taking each new request through to test and review within the coding standards.
  • Tracked errors in Sentry and took user feedback directly through Chatwoot into an automated AI workflow, so issues are fixed and answered quickly and accurately.
  • Built an AI analytics chat where students and parents ask about learning progress, streamed over SSE with per-role access checks and a daily rate limit.
  • Built homework OCR: scanned PDF pages become images so AI can read handwritten answers and marker ticks.
  • Built the whole backend alone for about 3,000 users: the PostgreSQL data model on Directus and Node.js APIs (Directus extensions, Express) for levelled exercises and reward points, with Twilio and CleverTap.

2023 - 2025

2.Medialabs

Project details:

AdTech / Marketplace

Media buying and advertising platform in Vietnam where advertisers book ad networks, websites, KOLs, and out-of-home inventory.

Technologies

  • Nuxt
  • Vue.js
  • Directus
  • Node.js
  • PostgreSQL
  • Redis
  • Typesense
  • REST API

Backend Engineer

Connects advertisers with media vendors through packaged media offers, campaign planning, and an agency and resource marketplace.

Achievements

  • Built the whole backend alone: designed the PostgreSQL data model on Directus for media inventory, packages, vendors, orders, and the partner directory.
  • Built the Node.js REST APIs for the Nuxt frontend: media booking, cart, orders, and saved items.
  • Used AI to plan and write the code for backend features.

Technical details

  • OnePay payments: a middleware that checks each transaction's hash signature, and QueryDR calls that update the payment status.
  • Budget-based media plans: turn a plan into a campaign, share it by email, re-invite, and clone a shared plan.
  • Invoices with slot, vendor, and parent-product discounts and an approval email; vendor withdrawal orders and revenue statistics.
  • Vendor and product search on Typesense; OTP with reCAPTCHA and per-IP rate limits on Redis.

Project details:

AV Technology / Corporate Website

Corporate website for a US audio-visual manufacturer, covering control, audio, and AV-over-IP product lines.

Technologies

  • Nuxt
  • Vue.js
  • Directus
  • Node.js
  • PostgreSQL
  • Algolia
  • REST API

Backend Engineer

Lets the marketing team publish products, case studies, training, webinars, and news from one headless CMS.

Achievements

  • Built the whole backend alone: designed the PostgreSQL data model on Directus for products, case studies, training, events, and news.
  • Built the Node.js REST APIs for the Nuxt frontend, including image transforms for responsive WebP delivery.

Technical details

  • Account registration API that assigns roles by email, sends a welcome email, and alerts admins to each new sign-up.
  • Daily and weekly email digests of updated portal documents, sent by cron according to each user's subscription.
  • Hooks that keep the Algolia search index in sync on every create or update, and process high-resolution images when a product changes.
  • Scheduled price-list updates across price types with an API to serve them, plus a license checker by order number and email.

Project details:

Fintech / Securities

Corporate website and investor portal for a Vietnamese securities firm, covering brokerage, derivatives, bonds, research, and online account opening.

Technologies

  • NestJS
  • Directus
  • Node.js
  • MySQL
  • Elasticsearch
  • Redis
  • Vue.js

Backend Engineer

Gives retail and institutional investors one entry point to market research, a live price board, and the firm's trading platforms.

Achievements

  • In a team of 10, owned the database structure: the MySQL schema on Directus for products, services, news, and multilingual market research.
  • Built the NestJS side of the website (SSR): search, market research, events, careers, and contact-form APIs, with content from Directus.
  • Synced content from Directus to Elasticsearch with hooks configured per collection (full reindex on start, updates on every create, edit, or delete), queried from NestJS for site search.

Technical details

  • NestJS middlewares for language, device detection, SEO redirects, login, file proxying, and uploads; interceptors that add SEO meta, schema, and breadcrumbs to each page.
  • A daily cron job that pulls news from an external API into Directus, keeping allowed categories with tags and translations; an SEO module for the Directus admin in Vue.

2023

5.Izion24

Project details:

InsurTech / E-commerce

Online insurance platform in Vietnam selling health, accident, travel, life, property, and vehicle insurance to individuals, families, and businesses.

Technologies

  • Nuxt
  • Vue.js
  • Directus
  • Node.js
  • MySQL
  • Redis
  • REST API

Backend Engineer

Lets customers compare and buy insurance online, with product content, promotions, and a blog managed from one headless CMS.

Achievements

  • Built the whole backend alone: designed the MySQL data model on Directus for insurance products, partner insurers, promotions, and blog content.
  • Built the Node.js REST APIs for the Nuxt frontend for product listing, comparison, and online purchase, with Redis caching.
  • Synced insurers, categories, products, plans, and benefits with translations from Izion's API into the CMS on a cron schedule, with an endpoint to rerun it on demand.

Technical details

  • Built proxy endpoints to Izion's API for phone OTP, policy lookup, account registration, and document download, managing the access token and verifying captcha.
  • Cached product analysis and shared data in Redis, refreshed by Directus hooks whenever editors change content in the CMS.

Need a full-stack developer for your product?

I take full-stack roles: Node.js APIs, databases, Vue and Next.js interfaces, and AI built into the workflow. Send the problem you are solving and I reply within two working days.

Duc Dao, 429 Linh Nam - Vinh Hung - Hanoi2026