congthiendev

Profile

Fullstack web developer building production React/Next.js frontends and Node.js/PostgreSQL backends, with hands-on experience in payment integrations, microservices on Kubernetes, and technical SEO / web performance.

I ship real products: solo-built commerce frontends with live Stripe/Klarna/PayPal checkout, event-driven backend services, and self-SEO'd sites scoring up to a perfect Lighthouse 100 across Performance, Accessibility, Best Practices, and SEO.

Core Strengths

• Frontend: React, Next.js (App Router), TypeScript, Tailwind CSS, GSAP / Framer Motion, responsive UI
• Backend: Node.js, Express, REST APIs, PostgreSQL, Redis, BullMQ workers
• Payments: PayPal SDK (sandbox → live), Stripe via dedicated payment service, Klarna checkout
• Microservices & DevOps: service-to-service calls in Kubernetes, Docker / Docker Compose, Nginx, GitHub Actions CI/CD, staging → production promotion
• Technical SEO: dynamic sitemaps, robots, JSON-LD schema, hreflang, Open Graph, Core Web Vitals
• Quality: Vitest unit tests, Playwright E2E, ESLint / Prettier, Husky pre-commit hooks

Project Highlights

Project	Technical Scope
stattner + prankbook (FRONTEND)	Solo-built the entire frontend for two production sites on Next.js 15 + TypeScript with SSR. Polished UX/UI, fast page loads (Lighthouse Performance 92–95, SEO 92–100). Integrated PayPal SDK (full sandbox → live flow), Stripe via a payment microservice, and Klarna checkout; frontend calls backend services over Kubernetes. Full technical SEO, Umami/Meta/Google tracking, GSAP/Framer Motion, Zustand state, Vitest + Playwright coverage
congthienagency.com	Personal agency site I built and SEO'd end-to-end — Next.js 15, bilingual (EN/VI). Perfect Lighthouse 100 / 100 / 100 / 100 (Performance, Accessibility, Best Practices, SEO). Ranks #1 on Google for brand terms with a Business knowledge panel — JSON-LD, hreflang, sitemaps, local SEO
serena_spa_hoian	Bilingual (EN/VI) Next.js spa site with a full booking-to-payment flow: browse services → add to cart → checkout & pay → automated confirmation email to the guest + service-detail email to the reception team. Lighthouse SEO 100, Performance 94–100 — hreflang, JSON-LD (LocalBusiness), next/image AVIF/WebP, dynamic per-locale metadata
influencer-service	Clean-architecture backend (api → controllers → services → models) for an influencer commerce/payout platform. Multi-provider payments & payouts (Stripe, PayPal, Wise, Payoneer, Binance/crypto), social verification (Instagram, YouTube, TikTok, Facebook), RabbitMQ email events, JWT auth, S3/MinIO storage, PostgreSQL migrations/seeds, Docker, CI, smoke + coverage tests

Performance Snapshot

Google Lighthouse / PageSpeed Insights

Site	Target	Performance	Accessibility	Best Practices	SEO
congthienagency.com	Desktop	100	100	100	100
stattner.com	Desktop	92	84	96	100
prankbook.com	Desktop	95	93	96	92
serena-spa	Desktop	100	87	100	100
serena-spa	Mobile	94	91	100	100

Workflow

I work in VS Code with a test-and-review-driven workflow, using AI assistants (Claude, Codex) to speed up prototyping and code review.

Tooling

Docker · Kubernetes · Nginx · PM2 · GitHub Actions · Postman · Figma