He's incredibly meticulous, checking every single detail as he works~~ Even the parts that were lacking, he handled well through smooth communication~!! I'll definitely come back for more development work next time~!! Thank you :)
Freelance Web Developer
Lee Guk-BeomFrom planning to deployment
I am a freelance developer handling the full journey of web services — planning, development, and deployment.

Trusted Reviews
Reviews from Clients
View on KmongHe was really fast and thorough, taking great care of everything. If I have another project, I definitely want to work with him again.
He asked about details I hadn't even thought of, so I've been very satisfied with the work so far :) If you're looking for a true expert, I can strongly recommend him! I expect I'll have more requests down the road, so I look forward to working with him again :)
Thank you for the professional handling and progress on the work.
Prompt response, flawless skills, and even follow-up support afterward — I was extremely satisfied!!
I made a last-minute request and he handled it wonderfully. He even asked about details that weren't in the spec, so nothing was missed during development. The source code was clean and the final result was clean too !!! I'll be requesting his work again. Thank you~
Great consultation, very good experience.
It was a tight schedule, but he paid close attention and delivered clean work.
To deliver the desired result quickly, he even reached out to other vendors to resolve issues — it was very reassuring to see. Wishing him continued success.
* Same project as above.
[Genuine, paid-for review] We had been struggling with a lot of difficulties, but thanks to this developer we were able to build things quickly. Before paying, I asked a ton of questions and he answered them all kindly, and even after payment he kept working fast. Communication was so quick that everything went smoothly. And above all, he was incredibly kind.. Since this was our first time outsourcing, we kept adding extra requests along the way, but he still handled everything quickly. This is the first time I've written such a detailed review — that's how satisfied and grateful I was. Thank you for all your hard work :)
Thank you again for the fast and accurate work. He has real discipline in how he works, so I could trust him and ask questions freely. I'm already planning a few follow-up tasks.
He consulted with me in detail over a long period, and even though it was a tricky project, he implemented exactly what I wanted. The best~!!!
He checked and handled everything as proactively as if it were his own project, which was very satisfying. That's why I hired him again for the next project :)
Fast feedback, and excellent both in problem-solving ability and speed. Thank you.
Thanks for all your hard work!
He communicated with me in real time throughout and worked kindly! I feel like you can trust him with your project~ I'd definitely consider hiring him again haha
Thank you so much for the fast and accurate work. It's a shame the rating only goes up to 5 stars. He used Notion to make giving feedback during the work efficient, and above all, the speed at which feedback was reflected was amazing. If I have work to do again, I definitely want to ask him again. Thank you!
Thank you so much for handling it so quickly.
Seriously fast turnaround, wow.
I made an urgent request and he handled it quickly. His skills are excellent and his understanding of code is great. If anyone else needs React-related work, I'd recommend leaving it to him.
I requested some additional work, and he resolved it well.
It was a challenging project, but he implemented it well. He reflected feedback right away and explained things clearly, so everything proceeded smoothly without much trouble. Thank you for the work.
Thank you for taking care of it so quickly.
He did clean, solid work!
Projects
Work History
Service names are hidden because their disclosure was not agreed upon with the clients in advance.
R*** — Motion Tracking Fitness Platform
Built a full-stack fitness coaching platform with real-time pose estimation via TensorFlow.js MoveNet, spanning backend, mobile, and tablet clients.
Software Supply Chain Security (SBOM) Platform
Delivered both frontend and backend for an enterprise SBOM governance system covering package intake review, vulnerability/license scanning, and reporting.
S*** — Digital Therapeutics Research Dashboard
Developed a dual-mode medical/research dashboard covering patient sleep reports, adherence tracking, and institutional member management.
Dental Staffing Matching Platform
Built a two-sided dental staffing marketplace end-to-end, from a NestJS/Prisma backend to the matching frontend.
S*** — AI Q&A Assessment Service
Built an AI-driven Q&A assessment service on Supabase and tRPC that tags user answers and generates ChatGPT-based responses.
Generative AI Web Chat Interface
Developed a production-grade AI chat UI with SSE streaming responses, conversation history, and multi-language support.
0*** — Web3 NFT Marketplace
Implemented a multilingual blockchain marketplace with Klaytn wallet connection and on-chain minting/trading flows.
M*** — Crypto Exchange Platform
Built the frontend for a comprehensive crypto exchange covering spot/futures trading, staking, P2P, and wallets.
G*** — Real Estate Investment Platform
Built a fintech real-estate investment service that presents loan/investment information alongside regulatory documents.
B*** W*** — Transaction Monitoring Dashboard
Developed an operations dashboard for reviewing bank transactions and exporting settlement records to PDF/Excel.
C*** — B2B Operations Admin
Built a Swagger-backed operations admin for account and data management, including AWS EC2 deployment and operations.
Rocket.Chat Customization
Customized authentication, localization, and integration modules within Rocket.Chat, a large-scale open-source real-time messaging platform.
R*** — Caption & Waveform Editor
Iteratively built a media editing tool for adjusting caption segments by dragging directly on the audio waveform.
O*** — Premium Travel Proposal Platform
Built dual customer/admin interfaces combining custom travel proposals, payments, and an operations back office.
L*** — Travel Curation Service
Progressively built a consumer service combining travel product discovery and community features, guided by design docs and IA.
B*** — Diving Leisure Booking Platform
Built a leisure booking system integrating reservations, payments, KakaoTalk notifications, and admin scheduling.
Hanteo Chart — Music Sales Aggregation Bridge
Built an integration server that forwards Shopify order data to Hanteo Chart’s API/FTP format for real sales aggregation.
Interactive Corporate Website
Built a high-quality brand site with library-free full-page animation and dedicated iOS Safari compatibility fixes.
T*** N*** — Trading Dashboard
Rapidly productized a trading-log dashboard with charts, forms, and panels directly from Figma deliverables.
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