> kriss.bui — portfolio
0%
Ho Chi Minh City, Vietnam
Open to Work — Backend roles
// backend.engineer — distributed systems
Bui
Duc Tri
I build event-driven systems that don't lose your data.
Backend engineer building high-throughput services, exactly-once workflows, and event-driven platforms — from enterprise loyalty systems to fintech ledgers.
$ about --verbose
Engineer behind the events
Proactive Backend Developer with 2+ years of hands-on experience building backend microservices, loyalty & reward platforms, and business web applications. Solid foundation in Java (Spring Boot 3), TypeScript (NestJS, Next.js 14), PostgreSQL, and Apache Kafka. Experienced in working directly with clients and external partner teams to clarify business requirements, deliver rapid MVPs, and implement reliable transaction flows using structured agentic AI workflows.
+30%
task delivery velocity
AI-augmented dev workflows (Codex, Claude)
−45%
server payload & transfer
Image processing & upload pipeline
−45%
avg API latency
Cache-aside + indexing, 500+ concurrent reqs
−90%
job failure rate
Reduced from ~15% to under 1.5% with BullMQ
$ integrations --production
6 platforms · 2025 — present
teso global
employer · current team
vitadairy
loyalty client
momo
payment gateway
salesforce
crm sync
urbox
rewards & vouchers
gotit
e-vouchers
$ experience --log
Event log
Four roles, one throughline: distributed systems that stay consistent under pressure.
$ log --since nov 2025 --until present
Ho Chi Minh City
TESO Global
Backend / Fullstack Developer
- Direct client & partner collaboration — technical point of contact alongside the Tech Lead in a 7-member squad, working with VitaDairy, UrBox, MoMo Payment Gateway and Salesforce CRM to align API contracts & webhook schemas and resolve integration issues during UAT and rollout.
- Loyalty, coin accumulation & lucky draw services — backend microservices (NestJS, Java Spring Boot 3, Apache Kafka) for enterprise loyalty/gamification campaigns: coin accumulation, lucky draw turns, affiliate events, MoMo reward transfers, Salesforce member sync.
- Reward redemption & data consistency — safe point deduction, gift quota tracking and fallback backup-voucher issuance using the Transactional Outbox pattern, idempotency keys and Redis distributed locks (cache-aside) across multi-tenant PostgreSQL, preventing race conditions during peak campaign traffic.
- Production Planning MVP (SNY VINA) — solo delivery: production planning web app (Next.js 14, Prisma 5.22, PostgreSQL on Neon, Vercel) built with direct client feedback; replaced 4 manual Excel files across 40 weaving machines with 2-step transactional Excel imports (Preview & Confirm), PostgreSQL table-level locking and optimistic concurrency control (409 Conflict).
- Agentic AI workflow & MCP automation — orchestrated Claude Code and Codex agents with custom Rules & Skills, Context7 MCP and Playwright MCP, accelerating boilerplate, Flyway migrations and feature delivery by ~30%.
NestJSSpring Boot 3Apache KafkaPostgreSQLRedisFlyway$ log --since jul 2025 --until sep 2025
Ho Chi Minh City
Viec.Co Corporation
Fullstack Developer
- Unified a staffing registration platform with Next.js, React, and Node.js — consolidating 100% of candidate onboarding data into a centralized source.
- Optimized the image processing and upload pipeline, slashing server payload and data transfer load by 45%.
- Dockerized services with multi-stage builds — cutting container image size by 20% and accelerating CD deployment cycles.
- Reached 90% unit/integration test coverage with Jest, React Testing Library, and MSW; zero regressions on critical flows.
Next.jsReactNode.jsDockerJestMSW$ log --since feb 2025 --until jun 2025
Ho Chi Minh City
Hopper Solution
Backend Developer (Freelance)
- Designed and built core backend services for FIORA, a financial SaaS platform, with Node.js, PostgreSQL, and Prisma ORM.
- Owned relational schema design, query optimization, and indexing to guarantee financial ledger integrity.
- Deployed containerized services via AWS Copilot, configured Redis caching layers, integrated secure Firebase token-based authentication.
Node.jsPostgreSQLPrismaAWS CopilotFirebase Auth$ log --since jan 2024 --until dec 2024
Ho Chi Minh City
Unicourse
Backend Developer
- Applied cache-aside strategy and indexed high-frequency queried columns — slashing average API response latency by 45% under 500+ concurrent requests.
- Built reliable notification and email pipelines with BullMQ: exponential-backoff retries plus Dead Letter Queues, reducing job failure rates from ~15% to under 1.5%.
- Maintained automated CI/CD deployment pipelines; optimized container build times and image sizes with Docker multi-stage builds.
Node.jsBullMQRedisPostgreSQLDockerCI/CD
$ work --selected
Selected work
Three systems I'm proud of — the architecture decisions behind them, and what they delivered.
case_study_01 — enterprise integration
Event-driven loyalty platform
TESO × VitaDairy / UrBox / MoMo / Salesforce — reward redemption engines where a lost event means lost money. Peak campaigns spike redemptions, so every conversion must be exactly-once.
Async core
NestJS + Spring Boot 3 microservices communicating via Apache Kafka — webhooks, loyalty point conversions, and affiliate events flow as durable messages.
Exactly-once
Transactional Outbox pattern + idempotency keys across PostgreSQL clusters — no duplicate redemptions, no silent drops.
Peak-proof
Redis distributed locks and cache-aside strategy eliminated race conditions during redemption spikes.
Zero data-loss incidents in production; task delivery velocity +30% via agentic dev workflows.
case_study_02 — fintech backend
FIORA financial SaaS backend
Hopper Solution (freelance) — core backend for a financial SaaS platform where ledger integrity is non-negotiable.
Ledger-first schema
Relational schema design with careful indexing and query optimization — every financial record traceable and consistent.
Secure by default
Layered auth with Firebase token-based authentication; secrets and sessions handled server-side.
Ship-ready
Containerized services deployed via AWS Copilot with automated CI/CD pipelines.
Ledger-grade integrity by design — composite indexes on ledger-critical paths, query plans tuned to real access patterns, Firebase token auth on every route, and containerized deploys via AWS Copilot, so the books reconcile line by line.
case_study_03 — solo delivery
Production Planning MVP — SNY VINA
Solo-built factory production planning web app, replacing 4 manual Excel files across 40 weaving machines — with direct factory feedback at every iteration.
Transactional imports
2-step Excel import flow (Preview & Confirm) so factory staff can validate data before anything is committed.
Concurrency-safe
PostgreSQL table-level locking plus optimistic concurrency control — conflicting edits return 409 Conflict instead of corrupting schedules.
Client-driven
Requirements gathered, MVP demos, and live feedback looped directly with factory stakeholders.
Deployed to production, replacing 4 manual Excel files across 40 weaving machines.
$ skills --stack
The stack
Grouped by where each tool earns its keep — backend first, as it should be.
Backend
- NestJS
- Node.js
- Java Spring Boot 3
- Express.js
- Prisma ORM
- TypeORM
- REST APIs
- Webhooks
Data & Messaging
- PostgreSQL
- MySQL
- Redis
- Apache Kafka
- BullMQ
- Transactional Outbox
- Idempotency
Integrations
- Salesforce CRM
- MoMo Payment Gateway
- UrBox API
DevOps
- Claude Code · Codex
- Docker
- AWS Copilot
- CI/CD
- Flyway
- Firebase
- MSW
- MCP Servers (Context7 · Playwright)
Frontend
- Next.js
- React
- TypeScript
- Jest
- React Testing Library
$ education --honors
Roots
degree
B.S. in Software Engineering
FPT University · Jan 2020 – Dec 2024
GPA 3.33 / 4.0
key focus
- Distributed Systems
- Algorithms
- Database Design
- Security
honors
Top 1 – Rocket Boost Entrepreneurial Competition
FPT University · Nov 2024
Top 10 Teams – 50M VND Scholarship Startup Project
FPT University
5× Honorable Student of the Semester
FPT University · 2023–2024
$ life --offline
Beyond the code
The people and moments behind the commits — demo days, team trips and office celebrations.
$ contact --open
Let's build something reliable
Currently open to backend engineering roles and interesting distributed-systems problems. My inbox is a durable queue — every message gets processed.
Currently open to Backend Developer opportunities — let's talk.