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.

Lee Guk-Beom

Trusted Reviews

Reviews from Clients

View on Kmong
4.96 / 5 · 25 reviews

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 :)

콩*****

Next.js 15 & React frontend

He was really fast and thorough, taking great care of everything. If I have another project, I definitely want to work with him again.

검*****

Next.js 15 & React frontend

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 :)

콩*****

Next.js 15 & React frontend

Thank you for the professional handling and progress on the work.

단*****

Next.js 15 & React frontend

Prompt response, flawless skills, and even follow-up support afterward — I was extremely satisfied!!

두*****

Next.js 15 & React frontend

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~

밝*****

Next.js 14 & React frontend

Great consultation, very good experience.

신*****

Next.js 14 & React frontend

It was a tight schedule, but he paid close attention and delivered clean work.

COE

2024-style React/TypeScript frontend

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.

다*****

React, Next.js & TypeScript frontend

* Same project as above.

따*****

React, Next.js & TypeScript frontend

[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 :)

따*****

React, Next.js & TypeScript frontend

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.

빠*****

React, Next.js & TypeScript frontend

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~!!!

매*****

React, Next.js & TypeScript frontend

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 :)

K29*****

React, Next.js & TypeScript frontend

Fast feedback, and excellent both in problem-solving ability and speed. Thank you.

시*****

Next.js 15 & React frontend

Thanks for all your hard work!

sma*****

React, Next.js & TypeScript frontend

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

공*****

React, Next.js & TypeScript frontend

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!

jin*****

React 18.2 + TypeScript 5

Thank you so much for handling it so quickly.

평*****

React & Next.js frontend development

Seriously fast turnaround, wow.

평*****

Next.js 15 & React frontend

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.

평*****

React & Next.js frontend development

I requested some additional work, and he resolved it well.

sep*****

React & Next.js frontend development

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.

sep*****

React & Next.js frontend development

Thank you for taking care of it so quickly.

sim*****

React & Next.js frontend development

He did clean, solid work!

덕*****

Next.js 15 & React frontend

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.

TensorFlow.jsMoveNetFlutterNode.js

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.

Spring BootTanStack QueryAG GridQueryDSL

S*** — Digital Therapeutics Research Dashboard

Developed a dual-mode medical/research dashboard covering patient sleep reports, adherence tracking, and institutional member management.

Next.jsZodChart.jsPlaywright

Dental Staffing Matching Platform

Built a two-sided dental staffing marketplace end-to-end, from a NestJS/Prisma backend to the matching frontend.

Next.jsNestJSPrismaJWT

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.

tRPCSupabaseOpenAI APITanStack Query

Generative AI Web Chat Interface

Developed a production-grade AI chat UI with SSE streaming responses, conversation history, and multi-language support.

SSE StreamingJotaii18n

0*** — Web3 NFT Marketplace

Implemented a multilingual blockchain marketplace with Klaytn wallet connection and on-chain minting/trading flows.

KlaytnWeb3next-intl

M*** — Crypto Exchange Platform

Built the frontend for a comprehensive crypto exchange covering spot/futures trading, staking, P2P, and wallets.

Next.jsStripePayPal

G*** — Real Estate Investment Platform

Built a fintech real-estate investment service that presents loan/investment information alongside regulatory documents.

ReactReact PDF

B*** W*** — Transaction Monitoring Dashboard

Developed an operations dashboard for reviewing bank transactions and exporting settlement records to PDF/Excel.

SupabasetRPCTanStack Table

C*** — B2B Operations Admin

Built a Swagger-backed operations admin for account and data management, including AWS EC2 deployment and operations.

Next.jsstyled-componentsAWS EC2

Rocket.Chat Customization

Customized authentication, localization, and integration modules within Rocket.Chat, a large-scale open-source real-time messaging platform.

Realtime ChatOAuthi18n

R*** — Caption & Waveform Editor

Iteratively built a media editing tool for adjusting caption segments by dragging directly on the audio waveform.

Peaks.jsWaveformMedia Editor

O*** — Premium Travel Proposal Platform

Built dual customer/admin interfaces combining custom travel proposals, payments, and an operations back office.

Next.jsChakra UIAG Grid

L*** — Travel Curation Service

Progressively built a consumer service combining travel product discovery and community features, guided by design docs and IA.

Next.js App Routershadcn/uiReact Hook Form

B*** — Diving Leisure Booking Platform

Built a leisure booking system integrating reservations, payments, KakaoTalk notifications, and admin scheduling.

SupabaseTossPaymentsFastAPI

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.

Shopify APIMongoDBFTP

Interactive Corporate Website

Built a high-quality brand site with library-free full-page animation and dedicated iOS Safari compatibility fixes.

GSAPnext-intlTailwind v4

T*** N*** — Trading Dashboard

Rapidly productized a trading-log dashboard with charts, forms, and panels directly from Figma deliverables.

RechartsRadix UIVite

What I Build

Services I can develop

✦Full-page animation-based landing pages
✦Google and Naver SEO
✦AI engine optimization (AEO, GEO)
✦Payment and refund systems implementation
✦First-come, first-served reservation systems implementation
✦Naver Map-based services
✦Multilingual (i18n) websites
✦Real-time UI synchronized with databases
✦WebAssembly and React integration
✦Browser-based real-time pose and motion estimation (computer vision)
✦Web3 wallet integration and on-chain transaction services
✦Generative AI chatbot and Q&A services with streaming responses
✦Backend LLM API integration with real-time streaming responses to users
✦On-device Q&A with lightweight AI models running directly in the browser
✦Automated PDF and Excel report generation for settlement documents
✦Operational admin and back-office tools with large-scale data grids
✦Integration bridges connecting commerce platforms to external industry systems
✦Automated KakaoTalk and SMS notification integration
✦Social login (OAuth) authentication systems
✦Healthcare domain services (patient and research data dashboards)
✦Desktop applications integrated with hardware such as cameras and printers
✦Media timeline tools such as video subtitle editors
✦Fintech and crypto exchange platform UI development

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