Rungroj Wongkaeo

I Build Backend Systems and Edge-Ready Web Apps That Scale Without Breaking the Bank

I'm a backend-focused Full-Stack Developer with 3+ years of experience shipping production systems for enterprise and manufacturing clients — from high-volume messaging platforms processing 1M+ requests per day to custom IoT/PLC integrations running on factory floors. I help businesses turn fragile legacy systems and manual processes into fast, reliable, and maintainable software.

Whether you need a new product built from scratch, an existing API that's buckling under load, or a legacy .NET/Excel-based workflow modernized — I bring a pragmatic, full-cycle approach: requirements, architecture, implementation, testing, and deployment.

What I Can Do For Your Business

Full-Stack Web Development — SvelteKit + Cloudflare Edge Modern, edge-deployed applications using SvelteKit, Cloudflare Workers/Pages, D1, and R2. The result: near-instant load times, global availability, and near-zero hosting costs compared to traditional server setups — ideal for startups and small businesses that need a professional web presence without ongoing infrastructure overhead.

Enterprise Backend Engineering — NestJS / .NET Core / Prisma Robust REST APIs and service architectures built with NestJS, .NET Core, and Prisma/TypeORM, backed by PostgreSQL, SQL Server, or MongoDB. Designed with proper testing, queueing (RabbitMQ), and caching (Redis) so your system stays reliable as usage grows.

High-Performance System Optimization I specialize in finding and fixing the bottlenecks that slow systems down at scale. Past work includes migrating an ORM layer (TypeORM to Prisma) and rewriting core logic for a system handling over a million daily messages — cutting processing overhead and improving stability under heavy load.

Legacy System Modernization & Integration Experience migrating legacy ASP Classic / AS400 systems to .NET Core, integrating low-code platforms (K2), setting up centralized authentication (Identity.NET with Keycloak/SSO), and building custom IoT/PLC data pipelines for real-time machine monitoring — without disrupting day-to-day operations.

Battle-Tested Tech Stack

Verified Technical Competence

A track record built on real production systems, backed by formal training:

• 9 software deployments delivered across 6 enterprise clients — covering employee assessment systems, IoT/PLC monitoring, and quality/calibration management platforms (SPC visualization: Histogram, Cp/Cpk, X̄–R)
• High-volume system ownership — optimized a NestJS SMS platform processing 1M+ messages per day in production
• Full SDLC delivery — requirement gathering, architecture, development, testing, and deployment, including a complete ASP Classic/AS400 to .NET Core migration

Completed Courses

Certifications

Education — B.Sc. in Applied Mathematics, King Mongkut's Institute of Technology Ladkrabang (2016–2020)

Let's Work Together

I'm available for freelance projects, consulting, and full-time opportunities — particularly backend systems, API development, system optimization, and full-stack product builds. If you have a project in mind, let's talk.