Skip to content
Bùi Hữu Tiến
Let's Talk

Work

Products I've built and contributed to, and the engineering behind them.

  • Prep4u homepage: free Digital SAT mock test with automatic scoring
    • EdTech · SAT
    • Production
    • 12K+ users

    Prep4u

    Digital SAT prep platform with 12K+ users. I designed and built its diagnostics and retention layer: score prediction, an adaptive placement test and a sales retention CRM.

    • Readiness Engine: Wilson lower bound + Bayesian smoothing, anti-gaming by design
    • Multistage adaptive placement test with row-locked submissions
    • Weakness Map that links each weak skill to targeted practice
    • Self-initiated sales retention CRM with cohort retention dashboard
    • Laravel
    • Livewire
    • Alpine.js
    • MySQL
    • Redis
  • Edly homepage: an IELTS and SAT/ACT platform for classrooms and exam rooms
    • EdTech · LMS
    • Production
    • 3K+ users

    Edly

    IELTS & SAT learning platform with 3K+ users and 61K+ questions. I created its dictation practice and pre-exam warm-up, and built module-based assignments and AI question analysis.

    • Dictation practice from IELTS Listening, AI translations checked by QA rules
    • Pre-exam warm-up: versioned config, idempotent server-side scoring
    • Module-based exam sharing and class assignments
    • OpenAI question analysis: transcripts, difficulty and category
    • Laravel
    • Vue 3
    • TypeScript
    • Inertia.js
    • MongoDB
    • OpenAI
    • AI / LLM
    • Automation
    • Internal tool

    AI Slack Check

    Self-initiated, solo-built internal tool: an LLM pipeline that turns free-form Vietnamese Slack messages into structured attendance data for HR, covering ~50 employees.

    • Hybrid rule-based + LLM extraction pipeline
    • Few-shot prompts with JSON schema validation
    • Human-in-the-loop: confidence score & audit trail
    • Incremental Slack sync & HR dashboard
    • Node.js
    • Fastify
    • TypeScript
    • Claude API
    • PostgreSQL
    • React
    • SaaS · Multi-tenant
    • B2B · Japan
    • 59 PRs merged

    Benerio

    Multi-tenant B2B SaaS that lets Japanese multi-location businesses manage Google Business Profile and Instagram / Facebook / Threads in one place. I built core GBP features, the partner agency tool and plan-bound access.

    • GBP module: business info, review replies, scheduled posts, analytics with PDF export
    • Partner agency tool: client management, drafts, schedules, failed-post handling
    • Plans and usage: accounts bound to plans, per-location permissions with RLS
    • Google OAuth linking and idempotent post sync (upsert + cleanup)
    • Next.js
    • TypeScript
    • Supabase
    • PostgreSQL
    • Tailwind CSS
    • Vercel
    • Backend
    • AI
    • Social mobile

    Snacktime AFP

    Backend API for a social mobile app where friends create AI-generated photos together.

    • Async AI image pipeline with Cloudflare Queues & Redis
    • Timezone-aware cron for automatic generation
    • Retry, distributed lock & rate limiting
    • Push notifications (FCM) & friends-of-friends suggestions
    • Cloudflare Workers
    • Hono
    • PostgreSQL
    • Redis
    • Firebase FCM