Currently working on
Outsourced CRM systems serving 5K – 10K users — finance, accounting, payments, and MLM commission engines.
Full-Stack Developer
Building thoughtful software for real-world business problems.
I'm letrucdev — a Full-Stack Developer who has shipped CRM systems serving 5K – 10K users. I work across React, Next.js, NestJS, Laravel, and .NET Core, and I care about clean architecture, performance, and the business problem behind the code.
Hoan Kiem, Vietnam
letruc.ts
1const letruc = {
2 role: "Full-Stack Developer",
3 location: "Hoan Kiem, Vietnam",
4 currentFocus: [
5 "CRM Systems",
6 "Scalable Web Apps",
7 "Clean Architecture",
8 ],
9 experience: {
10 frontend: ["React", "Next.js"],
11 backend: ["NestJS", "Laravel", ".NET Core"],
12 database: ["MySQL"],
13 tools: ["Git", "GitHub"],
14 },
15 projectsDelivered: 2,
16 usersServed: "5K - 10K",
17 motto: "Code with purpose, ship with confidence",
18};
About me
A Full-Stack Developer who treats clean code as a tool, not a goal.
I'm passionate about clean code, clear architecture, and performance optimization. Solving real business problems is more fun than chasing trends.
Currently learning
Angular, CI/CD workflows, and Proxmox for homelab and virtualization experiments.
Next goals
System design, microservices, and cloud-native architecture — moving from product to platform thinking.
Tech I work with
The tools behind real-world systems serving 5K – 10K users.
From frontend frameworks and backend runtimes to caching, realtime layers, and the infrastructure that ties it all together.
Languages
TypeScript
JavaScript
PHP
C#
HTML5
CSS3
Frontend
React
Next.js
Redux
Tailwind CSS
Backend
NestJS
Laravel
.NET Core
Node.js
Database & Cache
MySQL
Redis
Realtime
Socket.IO
WebSocket
Tools & Workflow
Git
GitHub
VS Code
Postman
DevOps & Infrastructure
Docker
Nginx
Reverse Proxy
Load Balancing
Networking
Cisco
Currently learning
Angular
GitHub Actions
GitLab CI
Proxmox
Featured projects
Two outsourced CRM systems, shipped end-to-end.
Both projects below are outsourced under client contracts. Due to NDA terms, I cannot publicly share source code, client names, screenshots, or specific technical details — what follows is a high-level overview of scope and role.
Project 01
CRM System — Finance & Accounting Platform
An outsourced CRM system serving enterprises with a comprehensive finance and accounting module.
Delivered10K+ usersOutsourceFrontend Lead 100%NDA — Confidential
Key features
- User management with RBAC permissions
- Enterprise finance and accounting management
- Payment processing with payment-gateway integration
- Multi-level marketing (MLM) commission with multi-tier genealogy tree
- Real-time dashboards and reporting
- Realtime updates via WebSocket — live notifications, dashboard data, transaction status
- Redis caching for high-frequency reads, session storage and rate limiting
My role
- Owned 100% of the frontend (Next.js) — UI/UX through performance optimization
- Collaborated directly with the Python (FastAPI) backend team and PHP WordPress API team
- Worked directly with the client to finalize business logic and UI requirements
- Reviewed and proposed improvements to the data flow between frontend and backend
- Integrated the WebSocket client for realtime data sync across modules
Tech stack
Next.jsFastAPIWordPress APIPHPMySQLRedisSocket.IO
Source code and client details are not publicly available due to contractual obligations.
Project 02
CRM System — User & Payment Management
A second outsourced CRM system focused on user management and large-scale payment flows.
Delivered5K+ usersOutsourceFrontend Lead 100%NDA — Confidential
Key features
- User management with multi-role authentication
- Accounting management and transaction reconciliation
- Payment-gateway integration and transaction processing
- Multi-level marketing (MLM) module — commission calculation and tree visualization
- Performance optimization for high concurrent user load
- Realtime processing via WebSocket — instant payment status, balance updates, user notifications
- Redis caching for hot data — sessions, MLM tree, transaction lookups — to reduce DB load
My role
- Owned 100% of the frontend (Next.js) — component architecture, state management, performance tuning
- Collaborated with the Python (FastAPI) backend team for the core API and PHP WordPress for the MLM commission module
- Worked directly with the client to deeply understand business logic and finalize UI/UX expectations
- Proposed API and UI structures suited for 5K+ concurrent users
- Implemented the WebSocket client with reconnect strategy and event-driven UI updates
Tech stack
Next.jsFastAPIWordPress APIPHPMySQLRedisSocket.IO
Source code and client details are not publicly available due to contractual obligations.
Want to know more about architecture, performance handling, or payment integration? Reach out and I'll share whatever the NDA permits.
Milestones & lessons learned
A real-world classroom — and a financial first.
$15,000+
Earned from outsourced projects
20
Age
2
Projects shipped
“These two CRM projects weren't just a financial milestone — they've been my biggest real-world classroom so far.”
What I learned
Frontend mastery
- Deeper grasp of Next.js — SSR, ISR, App Router, performance optimization.
- State management for complex systems with dozens of modules.
- UI/UX thinking when working directly with clients — translating business needs into interfaces.
Docker & DevOps
- Containerizing Next.js apps and packaging consistent dev/staging/production environments.
- Writing Dockerfiles and docker-compose for multi-service stacks (Next.js + FastAPI + WordPress + MySQL).
- Image layering, multi-stage builds, and image-size optimization.
Networking & infrastructure
- Reverse Proxy with Nginx — routing multiple services under one domain, SSL termination.
- Load balancing for systems with high concurrent user load.
- Networking fundamentals — DNS, ports, internal container networking, firewall rules.
- Configuring rate limiting, CORS, and security headers at the proxy layer.
Soft skills gained
Client communicationCross-team collaborationDeadline managementSystems thinking
Let's talk
Have a system that needs a thoughtful frontend?
I'm open to outsourced frontend work, full-stack collaborations, and freelance engagements — particularly for CRM, finance, and high-concurrency systems.