page 01 — hello!
Le Cong Hoan, an engineer who likes building systems that actually run.
Full-stack Engineer dedicated to crafting modern web applications, high-performance microservices, and reliable distributed systems. Focused on solving practical challenges through clean architecture, maintainable code, and seamless user experiences.
Angular · Next.js · Java / Spring Boot · Go · PostgreSQL · Kubernetes
Engineering Notes
Technical Writing & Architecture Notes
A project-linked engineering journal: enterprise reality, product decisions, infrastructure field notes, and systems experiments.
- 1.6Letting an LLM Act Inside a Financial Platform: Arda's AI Service BoundaryAn architecture note read from arda-be/apps/ai-service: how a model call reaches the platform through a gateway, a sandboxed tool catalog and a Postgres-backed approval state machine, and where the docs and the code still disagree.Oct 2026 · 14 min
- 4.3B4S: Reverse-Engineering a Bluetooth LE Companion for Baseus EarbudsA build log of an unofficial desktop app for Baseus earbuds: two wire framings (bare AA/BA and a 789C frame with CRC-16), a Rust session model that refuses stale state, 124 catalog profiles of which 7 can send commands, and an honest list of what is still unverified.Feb 2026 · 14 min
- 1.1How Arda Is Put Together: 15 Go Services, One WorkspaceAn engineer's map of Arda as the repo stands today: 15 Go services of very different sizes, gRPC inside and HTTP at the edge, NATS events, 18 shared libraries and their coupling cost, the newer loan/deposit/capital/statistical/AI services, the GHCR to Argo CD path, and a candid list of what is still rough.Feb 2026 · 12 min
- 1.3Transactional Outbox on NATS JetStream: What Arda's Six Relays Actually GuaranteeA decision record read from the code: how arda-be writes events in the same Postgres transaction as state, how six services relay them to one JetStream stream, where at-least-once ends, and where the implementations disagree.Jan 2026 · 10 min
- 1.5A Shell and Thirteen Remotes: Reading Arda's Module Federation SetupAn audit of arda-mfe as it stands: one Vite shell, thirteen remotes mapped by a 42-prefix route registry, twenty shared singletons with requiredVersion off, a per-route error boundary, and two deploy paths that disagree about how many remotes exist.Feb 2026 · 11 min
- 2.1Building Puchi: From Product Idea to Service ArchitectureDeriving backend service boundaries from product domain needs: Next.js PWA, Go Kratos v3 monorepo (auth, core, learn, media, notification), NATS event bus, and Cloudflare R2 audio streaming.Jan 2026 · 10 min
Selected Work
Featured Systems & Architecture
Professional systems, products, and infrastructure—each connected to the engineering notes behind its important decisions.
- 12/2024 – PresentEPAS — Enterprise Process Automation SystemConfigurable workflow platform for lending, disbursement, operations, and reporting across credit institutionsAngular · Micro-Frontend · Java Spring Boot · Oracle · PostgreSQL
- 2025 – PresentArda — Multi-Tenant Financial Operations PlatformCloud-native platform with 15 Go microservices (gRPC & NATS), React Module Federation (13 remotes), and Ory IAMGo · gRPC · NATS · React · Module Federation
- 2025 – PresentPuchi — Vietnamese Language Learning PlatformNext.js PWA with 5 Go microservices (Kratos v3), Limen sessions, NATS events, and ArgoCD GitOpsGo · Kratos v3 · Next.js · PWA · NATS
- 2025 – PresentCamrelay — P2P IP Camera to RTSP Stream RelayRust/Tokio tunnel that puts a P2P-only camera behind a private, authenticated RTSP endpointRust · Tokio · RTSP · P2P Signaling · FFmpeg
Career Journey
Work Experience
Track record of delivering enterprise-grade web platforms and cloud-native infrastructure.
12/2024 — Present
Hanoi, Vietnam
Fullstack Developer · NGV Group
Driving enterprise process automation systems (EPAS), real-time Zalo OA communication modules, and managing on-premises Kubernetes/CI-CD infrastructure.
- Designed and maintained Angular micro-frontend architecture, shared libraries, routing, integration patterns, and reusable UI foundations across enterprise modules.
- Built reusable Angular UI capabilities for dynamic forms, data tables, pagination, attachments, and activity history.
- Implemented CRM/BPM workflows covering transaction inboxes, task management, customer flows, and business-process interactions.
- Integrated frontend modules with Java Spring Boot microservices and Oracle/PostgreSQL data flows for enterprise operations.
Angular · Micro-Frontend · Java Spring Boot · Oracle · PostgreSQL · Redis · Kafka · Keycloak · Minio · Kubernetes · Docker · Jenkins
03/2024 — 08/2024
Hanoi, Vietnam
Frontend Developer · MochiMochi
Developed learner-facing web applications, improved Core Web Vitals performance, strengthened SEO rankings, and modularized reusable UI component libraries.
- Developed and maintained learner-facing web applications for Japanese and Chinese language learning using Next.js.
- Improved Core Web Vitals and SEO through rendering and asset optimization, page structure, and metadata improvements.
- Refactored legacy code, upgraded framework and dependencies, and standardized reusable components to improve maintainability and development velocity.
Next.js · React · TypeScript · Tailwind CSS · SEO · Responsive UI
Tech Stack
Tech Stack & Tooling
Technologies applied in production systems, structured by what was built with each tool.
- Frontend Engineering
Component architecture, micro-frontends, and performance optimization
- Angular
- Next.js
- TypeScript / JavaScript
- React
- Backend & Microservices
High-throughput APIs, distributed messaging, and enterprise security
- Java / Spring Boot
- Go (Golang)
- Apache Kafka
- Keycloak & MinIO
- Databases & Storage
Relational integrity, SQL query tuning, and distributed caching
- Oracle Database
- PostgreSQL
- Redis
- DevOps & Cloud-Native
Automated pipelines, multi-node K3s homelab, and container orchestration
- Kubernetes & K3s
- Docker
- Jenkins CI/CD
- Linux & Homelab
Get in Touch
Let's build something valuable together.
I'm interested in building scalable web platforms, enterprise systems, and developer infrastructure with modern frontend, backend, and cloud-native technologies.
- lehoan.dev@gmail.com
- GitHub
- github.com/hoan02
- linkedin.com/in/hoan02
- CV
Hanoi, Vietnam • UTC+7
hiring?
Send me an email!
Full-stack engineer in Hanoi, open to remote and hybrid roles. My CV and code are linked below.
Le Cong Hoan · Full-stack Engineer & System Builder · Hanoi, Vietnam • Available for Remote / Hybrid