Dongwook Jung | Backend & WebRTC Engineer

Intro About myself

Dongwook Jung

B.S. in Computer Engineering, Inha University

Software Engineer / Business Automation — DAWON MEAT (Nov 2024 – Present)

WebRTC Platform & Service Development — TmaxCloud (Aug 2022 – Nov 2024)

WebRTC Platform & Service Development — KnowledgePoint (Aug 2019 – Apr 2022)

Software Engineering Intern — Xiitec (Mar 2016 – May 2016, Vancouver, Canada)

Skills Core Expertise

REAL-TIME COMMUNICATIONS

WebRTC (SFU / MCU)
SDP / ICE
Socket.IO
Janus Gateway

BACKEND

Node.js
REST API Design
Real-time Signaling

DATA & INFRASTRUCTURE

Redis
PostgreSQL / MySQL
AWS
Scalable Infrastructure

ENGINEERING LEADERSHIP

Team Leadership & Mentoring
System Design
Performance & Load Testing

Selected Work Case Studies

DAWON MEAT computer vision demo showing original meat image, segmentation result, and detected fat ratio — DAWON MEAT — Business Automation & AI

Client Problem
A traditional meat distribution business relied on fragmented manual workflows for orders, warehouse operations, inventory, and quality assessment.

What I Built
- Architected and deployed a custom web-based Order Management System from scratch as a solo engineer, replacing phone/SMS order intake with a centralized workflow and structured work lists.
- Integrated an enterprise ERP system to simplify inventory and accounting operations and introduced client-specific sales and stock tracking.
- Introduced workflow changes incrementally to overcome resistance from legacy staff, earning adoption through measurable operational improvements.
- Developed a browser-based computer-vision prototype using OpenCV.js, GrabCut, and HSV segmentation to estimate visible fat distribution in meat images.
- Established a more standardized pricing framework after identifying risk in ad-hoc client-specific pricing practices.

Value Delivered
Reduced order-entry errors and operational ambiguity, improved inventory/accounting workflows, and supported a broader digital transformation of a traditional distribution business.

TmaxCloud enterprise WebRTC platform — TmaxCloud — Enterprise WebRTC Infrastructure

Challenge
Build and scale enterprise meeting infrastructure while reducing dependency on open-source media components and validating reliability under high concurrency.

My Role
Software Engineer / Team Lead — led and mentored 6 engineers, guided high-level system design, coordinated work across framework and messenger dependencies, and helped re-prioritize delivery when requirements and platform architecture shifted.

What I Built
- Engineered a hybrid SFU/MCU architecture supporting meeting rooms of up to 300 concurrent participants.
- Developed dynamic video mixing that composited up to 16 active streams into one optimized feed.
- Reduced client-side processing load by moving audio aggregation toward server-side mixing and using simulcast to select video quality based on receiver conditions.
- Designed and implemented 30+ REST APIs for meeting reservation and scheduling.
- Built a custom server-as-a-client simulation tool for automated high-traffic WebRTC testing.
- Conducted deep analysis of SDP and ICE and produced foundational sample code for an in-house media server, reaching the WebRTC PeerConnection connected state.
- Delivered a public-sector WebRTC deployment meeting a target capacity of 100 concurrent users.

Technologies
WebRTC, SFU/MCU, SDP, ICE, Simulcast, Node.js, Java, C++

KnowledgeTalk WebRTC CPaaS — KnowledgeTalk — WebRTC CPaaS

Challenge
Transform repeated client-specific WebRTC implementations into a reusable product platform that external teams could integrate quickly and operate at scale.

What I Built
- Proposed and helped drive a ground-up redesign of the legacy CPaaS architecture after building a working prototype and integration guide to demonstrate the value of a cleaner modular API design.
- Migrated the platform infrastructure to AWS and redesigned the legacy deployment for horizontal scale-out and production load testing.
- Launched the proprietary KnowledgeTalk CPaaS and designed RESTful APIs used across 6 enterprise client services, supporting a pay-per-minute business model.
- Built a JavaScript SDK that abstracted signaling and message handling, reducing client integration time from several weeks to a few hours.
- Designed scalable signaling servers with Node.js, Socket.IO, and Redis for hundreds of concurrent real-time connections in major enterprise services.
- Designed custom multi-video-room orchestration around Janus Gateway for scalable N:N multiparty conferencing.
- Added TensorFlow.js-based background processing and remote media-control capabilities.
- Built and operated AWS infrastructure for production WebRTC services and authored developer integration documentation and practical onboarding guides.
- Diagnosed and fixed backend synchronization issues by refactoring Redis state structures and execution order rather than applying narrow patches.

Technologies
Node.js, Socket.IO, Redis, Janus Gateway, WebRTC, REST APIs, AWS, JavaScript SDK, TensorFlow.js

Developer Documentation

Additional Experience Production Services

Episoden — Episoden — Real-time 1:1 English Conversation

Responsibilities
- Owned system configuration, maintenance, and AWS server setup.
- Redesigned the partner-matching approach after consulting an external university professor specializing in algorithms, then implemented a Stable Roommates-based matching algorithm using user preferences, English level, nationality, and other conditions.
- Contributed to service pages enabling WebRTC video communication between users across multiple countries.
- The service originated from an internal real-time communication product concept that later pivoted into an English conversation platform.

Haebeop Edu video solution — Haebeop Edu — Video Education Solution

Responsibilities
- Owned system configuration, maintenance, and AWS server setup.
- Contributed to a WebRTC education service providing chat, video communication, screen sharing, annotation, and class-observation features.

KORAD remote technology transfer service — KORAD — Remote Technology Transfer Service

Responsibilities
- Owned system configuration, maintenance, and server setup.
- Developed a Java Spring RESTful API server.
- Contributed to a WebRTC consulting service with chat, video consultation, and screen sharing.

Nesin.com admissions consulting service — Nesin.com — Admissions Consulting

Responsibilities
- Owned system configuration, maintenance, and AWS server setup.
- Contributed to a WebRTC admissions consulting service with chat, video consultation, and screen sharing.

Online lottery service — XiiTec — Online Lottery Service

Responsibilities
- Maintained and updated an online lottery purchasing service during a software engineering internship in Vancouver, Canada.
- Implemented a custom Lottery Wheeling System algorithm in JavaScript.