SJ System
Developer and operator of STAYTOQ, our own AI SaaS

The AI company that built STAYTOQ

WHAT WE BUILD

What we do: AX Consulting, AI Chatbots, Android & iOS Apps, Websites, Systems

SJ System is an AI development company that built STAYTOQ in-house — an AI chatbot SaaS for lodging businesses, now running as a live service at customer properties.

Start a project

First consultation is free · No obligation to proceed

Mission

We give our customers their time back.

AI takes on the repetitive work, so people can spend their time on what only people can do.

Read our mission and vision →
// 01 — credentials
16 years
Enterprise system development experience

Designed and built systems including emart24's ERP and POS, the Korea Forest Service's ‘Supnadeul-e’, Starbucks mobile, and an AI help desk for a large enterprise.

Live in production
STAYTOQ, our own AI chatbot SaaS

Since launching in May 2026, it has handled 2,718 inquiries in total at real lodging properties.

Mail-order business registration
No. 2026-Goyang Deogyang-gu-1374

Our own payment system, StayPay, meets the requirements to process bookings, payments and refunds directly.

// 02 — ax-consulting
AX Consulting · AI Transformation

We start by finding where AI should actually be used.

AX (AI transformation) is not about adding a chatbot. It starts with finding where your time is being lost today, then deciding which of that work to hand to AI and which people should keep doing.

At SJ System, one team takes it all the way — from that diagnosis to building the system and operating it after launch.

CONTINUOUS LOOPSTEP 1DiagnoseSTEP 2DesignSTEP 3BuildSTEP 4Verify
Once results are verified, we find the next transition point and diagnose again. We don't build once and walk away.
  1. STEP 1

    Operations Diagnosis

    We break your day down hour by hour. Using real data, we check what inquiries come in and how many, where they repeat, and at what times they are being missed.

  2. STEP 2

    Transformation Design

    We separate what AI will take over, what the system will automate, and what people need to keep doing. We don't push to switch everything to AI — we tackle the highest-impact items first.

  3. STEP 3

    System Development

    We build it ourselves — AI chatbots, admin systems, reservations and payments, and websites. Because the team that designed it also develops it, requirements don't get lost in handoffs.

  4. STEP 4

    Results Verification

    We measure success not by how many features we shipped, but by how many hours we gave back. Response volume, response rate and time saved are checked in numbers every month.

It doesn't end with a report

Consulting that diagnoses and leaves only hands the owner more homework. With us, the people who run the diagnosis build the system, and the people who build it operate it to the end. We don't outsource or subcontract.

Yangju JamJam Glamping & Caravan

A case that began with AX Consulting and continued through system development. We moved the time tied up in repetitive inquiries and scattered channels over to AI, and brought reservations, settlement and cleaning schedules together in a single admin system, improving operational efficiency and productivity.

38.5 hrs
Response time saved per month
770 chats
Auto-replies per month
96.4%
AI response rate
See case studies →
More about AX Consulting →
// 03 — services

Services

The team that designs your AI transformation also builds and runs the chatbots, apps and websites.

AX Consulting (AI Transformation)

We start by working out with you where AI should actually be used. We diagnose your operations, design the points of transformation, and the same team that ran the diagnosis builds and operates the result.

  • Operations diagnosis — analyzing real data to find where time is being lost
  • AI transformation design — separating what AI replaces, what gets automated, and what people keep doing
  • Consulting and building by the same team — we don't hand over a report and leave
  • Results measured in time — 38.5 hrs saved per month at Yangju JamJam
Learn more →

AI Chatbot Development & Operation

We build and operate STAYTOQ, our own AI chatbot SaaS for the hospitality industry. With the same technology, we build AI customer-service chatbots tailored to your industry.

  • STAYTOQ, our in-house SaaS — developed and operated in live service
  • Unified responses across 4 channels: web, Naver TalkTalk, KakaoTalk and Instagram DM
  • Industry-specific AI customer-service chatbots · widget installation on existing sites
  • Automation of repetitive tasks · AI work tool development

Android & iOS App Development

We build Android and iOS together from a single project. We are currently developing CallPop, JudoSystems' restaurant platform, as a hybrid web app.

  • Simultaneous Android and iOS development and app store submission
  • Native feature integration, including push notifications, maps and authentication
  • Admin web and dashboards built alongside
  • CallPop hybrid web app development — outsourced by JudoSystems, in development
All services →
// 04 — ai-team

AI Development Team

At SJ System, one CEO works alongside a team of AI teammates.

Assistant, developer, marketing and accounting AI each take on a role and handle real work, and nothing is applied until the CEO has reviewed and approved it. We bring the same way of working we use every day to client projects.

Jiheung Jeong, CEO of SJ System
CEO, SJ System · Backend & AI developer, 16 years

Jiheung Jeong

I spent 16 years building enterprise systems. Now I use the same approach to help small businesses.

Meet our CEO →

Assistant AI

Claude Sonnet

Takes the CEO's instructions, breaks them into tasks, assigns them to the right AI, and reports on progress.

  • Breaks instructions received over chat into task cards
  • Assigns the responsible AI · sets priorities
  • Reports progress and completion

Developer AI

Claude Opus

Writes the actual code according to assigned task cards. Works in an isolated workspace, and changes are applied only after the CEO reviews and approves them.

  • Writes and modifies code based on task cards
  • Works in an isolated workspace without touching production code directly
  • Shows changes to the CEO and applies them only after approval

Marketing AI

Claude Sonnet

Drafts Instagram card news and newsletters to promote STAYTOQ. Nothing is published without the CEO's approval.

  • Plans and drafts Instagram card news
  • Drafts newsletters
  • Publishes only after CEO approval

Accounting AI

Claude Sonnet

Records revenue and expenses, tracks receivables, and summarizes and reports the financial position.

  • Records revenue and expenses
  • Tracks receivables and confirms payments
  • Monthly financial summary reports

Every AI teammate's output passes through a CEO approval gate — no AI deploys or publishes anything on its own.

// 05 — production-metrics

Proven in production

Real results from building and operating our own AI chatbot, STAYTOQ, for Yangju JamJam Glamping & Caravan (as of August 2026).

staytoq — production metrics

$ staytoq metrics --tenant yangjujamjam --month 2026-08

  • Auto-replies in August770 chats
  • AI response rate96.4%
  • Response time saved in August38.5 hrs
  • In the knowledge base448 Q&As

# source: live operating data from Yangju JamJam Glamping & Caravan (August 2026)

$

See case studies →
// 06 — latest-build

Latest project

Website Development · STAYTOQ AI Chatbot

Goeunheuk (Pure Raw Red Clay Manufacturing & Supply)

SJ System planned, designed and developed the website for Goeunheuk, which manufactures and supplies raw red clay (hwangto) from a clean region of Boryeong, South Chungcheong Province. The site presents product specifications, applications and red clay path installation cases in a single flow, and includes STAYTOQ, our in-house AI chatbot, so inquiries are handled 24 hours a day.

  • Built a website organizing products and grain sizes (1.5, 2.5, 5mm) by use — from 20 and 25kg small bags to 500kg and 1-ton bulk bags and red clay–decomposed granite blends
  • Provided applications such as red clay paths, EM clay balls, water purification, fish farm application, plastering/ondol/hanok roof tiles and livestock barns, along with an installation gallery and a product brochure PDF
  • Installed STAYTOQ, our in-house AI chatbot, to answer inquiries about specifications, quantities and delivery 24 hours a day and connect to phone consultations
  • Designed mobile optimization together with search (SEO), directions and click-to-call paths
Visit 고은흙.com ↗See how we built it →
// 07 — products

Our products

We don't only build for clients. These are products we designed, built and run ourselves.

STAYTOQ

A 24-hour AI chatbot agent for lodging business owners

STAYTOQ is our own AI chatbot SaaS, developed by SJ System and operated in live service. It answers inquiries for glamping sites, pensions and pool villas — including those that arrive in the middle of the night — and automatically responds across 4 channels at once: web, Naver TalkTalk, KakaoTalk and Instagram DM. It can also be added as a widget to websites and businesses outside the lodging industry.

Learn more →staytoq.com ↗
// 08 — admin-system

We build the operating system, too

We didn't just build a chatbot. SJ System develops and operates the entire admin system owners use to actually run their properties.

Six areas — from AI responses to reservations, sales, website and task automation — are managed in a single admin. It is a multi-tenant architecture: data is separated per business, and the menus shown depend on each user's role.

STAYTOQ AI

See what the chatbot handled and how much, and fix answers on the spot.

  • Dashboard
  • Inquiry & answer analytics
  • Basic information
  • Settings
  • Subscription billing

Reservations

Bring all reservations into one place and manage check-in, check-out and cleaning just as they happen on site.

  • Reservation status · Calendar
  • Check-in/out board · Check-in/out assignment
  • Cleaning schedule
  • Guest analytics · Messaging
  • Email import · Data consistency check

Sales

Take bookings and payments directly, through to settlement. Room inventory is kept in sync to prevent overbooking.

  • Product management · Quick reservation management
  • Settlement (StayPay)
  • Coupons / Promotions
  • Product & option linking
  • Room inventory sync

Website

Owners edit their property website themselves. No need to call a developer.

  • Site settings
  • Room information · Amenities
  • Images · Nearby attractions
  • Reviews · FAQ
  • Blog & notices · Legal pages

Task Automation

Schedule recurring promotional posts once and forget about them.

  • Instagram posting
  • Threads posting
  • Naver Blog
  • Channel connection settings

Marketing

Compare with nearby properties as a reference when setting prices.

  • Competitor analysis
  • Quote calculator
staychat.kr/admin ↗More about STAYTOQ →

As this is a live production system, signing in requires an owner account.

// 09 — faq

Frequently asked questions

What kind of company is SJ System?

SJ System is an AI development company that built STAYTOQ, an AI chatbot SaaS for lodging businesses, in-house and runs it as a live service. It was founded on March 10, 2023, and its CEO is Jiheung Jeong. After diagnosing a client's workflows through AX Consulting (AI Transformation), the same team builds the apps, websites and systems and keeps running them after launch.

What services does SJ System offer?

SJ System offers the following services: AX Consulting (AI Transformation), AI Chatbot Development & Operation, Android & iOS App Development, Website Development, System Development, Operation & Maintenance. Because one team handles consulting, development and operations, what we diagnose is built directly into the system.

What is STAYTOQ?

STAYTOQ is an AI chatbot SaaS for lodging businesses, developed and operated by SJ System. It answers guest inquiries automatically, 24/7, across 4 channels (Website widget, Naver TalkTalk, KakaoTalk, Instagram DM), and replies only with information the owner has confirmed. Pricing is KRW 29,000–99,000 / month (Based on business size, channels and inquiry volume · VAT excluded · No contract · 15-day free trial). Learn more at https://staytoq.com.

What does AX Consulting (AI Transformation) involve?

SJ System's AX Consulting runs in four stages: workflow diagnosis → transformation design → system build → results validation. We separate the work AI should take over, the work systems should automate, and the work people should keep doing, and the team that ran the diagnosis builds and operates the result. Yangju JamJam Glamping & Caravan cut its guest-response time by 38.5 hours over the month of August 2026.

What projects has SJ System delivered?

Our flagship case is Yangju JamJam Glamping & Caravan. SJ System built everything — AX consulting, the website, the STAYTOQ AI chatbot, booking and payment through our own StayPay, and the admin system — and it has handled 2,718 inquiries in total since May 2026. Other projects include the Goeunheuk website with STAYTOQ built in, and CallPop, a restaurant discovery platform (hybrid web app) in development for JudoSystems.

Who is the CEO of SJ System?

The CEO of SJ System is Jiheung Jeong. A backend and AI developer with 16 years of experience, he designed and built emart24's next-generation ERP and POS, the Korea Forest Service's ‘Supnadeul-e’, the Starbucks mobile upgrade, and an in-house AI help desk for a large enterprise. At SJ System he personally handles consultation, design, development and operations.

How do I contact SJ System?

Leave a message on the contact page of the SJ System website (sjsystem.ai.kr/contact) and it goes straight to the person in charge. You can also reach us by email (sjsystemadmin@gmail.com) or phone (010-6305-7562), or ask the STAYTOQ chatbot in the bottom-right corner of the site first.