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About

Katchi

Katchi

Redefining Language Exchange Through Structure, Safety, & AI

Katchi (meaning together in Korean) is a purpose-driven language exchange platform for serious learners, where every conversation gets you one step closer to mastering the language. Unlike existing language exchange apps today that do little facilitate conversations, Katchi helps learners build consistent, prompt-based practice in a safe environment.

① PROBLEM STATEMENT & GOALS
Language exchange apps that don't actually teach

① PROBLEM STATEMENT & GOALS

Most language exchange apps promise conversation, but fail to deliver productive learning. They attract users seeking casual conversation rather than committed practice, leading to:

  • Unstructured, unfocused conversations that don’t support real language growth

  • Partners with mismatched intentions and inconsistent goals

  • Unsafe or uncomfortable behavior that discourages serious learners

While existing language exchange apps like HelloTalk and Tandem are feature-rich, these environments do not facilitate productive learning.

After spending 9 months studying in Seoul and feeling frustrated by my attempts to learn Korean through language exchange, I set out to design an app that facilitated productive learning and connected serious language learners.

Design Challenge: How do we create a platform that encourages sustained learning, facilitates matches based on genuine study goals, and facilitates productive language learning?

② DEFINING THE PRODUCT VISION
Serious learning needs serious structure

② DEFINING THE PRODUCT VISION

Katchi is positioned as a purpose-driven language exchange platform, for serious learners who want structured practice, real feedback, and safe, goal-based connections. Our focus is on quality over quantity of interactions and treating conversation as a study method, not merely a social hobby.

Katchi blends design, AI, and behavioral psychology to build a structured and safe ecosystem for sustained learning.

Core Principles

01. AI-powered learning - transforming every chat into productive learning sessions

02. Goal-aligned exchange - matching learners by intent, proficiency, and study focus

03. Safety-first matching - ensuring comfort, respect, and commitment to real learning

③ AI AS THE LEARNING COMPANION
AI that coaches without taking over

AI sits at the center of Katchi’s learning experience by enhancing conversation, not replacing it.

Core Capabilities

01. Goal-Aligned Partner Matching

Katchi analyzes each learner’s goals, proficiency, grammar focus, and availability to recommend partners who match their study intent—not their appearance.

Before each session, AI generates suggestions to prepare for your call, highlighting your partner’s goals and what they’re practicing, as well as some suggested topics.

02. AI-Driven Conversation Prompts

Katchi’s AI generates contextual prompts for both partners, guiding the conversation toward practical use of the grammar or vocabulary they’re studying, so every session becomes deliberate practice.

During a session, Katchi also provides lightweight, real-time feedback: when it detects an error, missed opportunity, or teachable moment, it quietly surfaces suggestions or example sentences without interrupting the flow of the call.

03. AI-Powered Post Session Recap

To encourage users to utilize Katchi for their practice sessions, valuable insights will be surfaced after each session:

  • Full transcript and voice recording

  • AI-generated corrections and improvement suggestions

  • Suggested vocabulary to review

This turns real-world dialogue into personalized, reusable study material, something no traditional language exchange app provides.

AI sits at the center of Katchi’s learning experience by enhancing conversation, not replacing it.

Core Capabilities

01. Goal-Aligned Partner Matching

Katchi analyzes each learner’s goals, proficiency, grammar focus, and availability to recommend partners who match their study intent—not their appearance.

Before each session, AI generates suggestions to prepare for your call, highlighting your partner’s goals and what they’re practicing, as well as some suggested topics.

02. AI-Driven Conversation Prompts

Katchi’s AI generates contextual prompts for both partners, guiding the conversation toward practical use of the grammar or vocabulary they’re studying, so every session becomes deliberate practice.

During a session, Katchi also provides lightweight, real-time feedback: when it detects an error, missed opportunity, or teachable moment, it quietly surfaces suggestions or example sentences without interrupting the flow of the call.

03. AI-Powered Post Session Recap

To encourage users to utilize Katchi for their practice sessions, valuable insights will be surfaced after each session:

  • Full transcript and voice recording

  • AI-generated corrections and improvement suggestions

  • Suggested vocabulary to review

This turns real-world dialogue into personalized, reusable study material, something no traditional language exchange app provides.

③ AI AS THE LEARNING COMPANION
AI that coaches without taking over

AI sits at the center of Katchi’s learning experience by enhancing conversation, not replacing it.

Core Capabilities

01. Goal-Aligned Partner Matching

Katchi analyzes each learner’s goals, proficiency, grammar focus, and availability to recommend partners who match their study intent—not their appearance.

Before each session, AI generates suggestions to prepare for your call, highlighting your partner’s goals and what they’re practicing, as well as some suggested topics.

02. AI-Driven Conversation Prompts

Katchi’s AI generates contextual prompts for both partners, guiding the conversation toward practical use of the grammar or vocabulary they’re studying, so every session becomes deliberate practice.

During a session, Katchi also provides lightweight, real-time feedback: when it detects an error, missed opportunity, or teachable moment, it quietly surfaces suggestions or example sentences without interrupting the flow of the call.

03. AI-Powered Post Session Recap

To encourage users to utilize Katchi for their practice sessions, valuable insights will be surfaced after each session:

  • Full transcript and voice recording

  • AI-generated corrections and improvement suggestions

  • Suggested vocabulary to review

This turns real-world dialogue into personalized, reusable study material, something no traditional language exchange app provides.


CAPABILITY 01

Goal-Aligned Partner Matching

④ DESIGN PROCESS
From casual conversation to deliberate practice


01. Goal-Aligned Partner Matching

Most language exchange apps struggle with mismatched expectations, one partner wants structured practice while the other just wants to chat. Katchi solves this by matching users based on intent, learning style, and study goals.

During onboarding, learners share their goals, preferred correction style, speaking ratio, and session structure. Katchi’s AI uses this to recommend partners who are equally motivated and aligned in how they want to learn.

Before each session, users receive a brief Prep Summary with shared goals and suggested topics, so both partners enter the call with clarity and purpose.

Result: More compatible matches for practice sessions that feel productive from the start.

Most language exchange apps struggle with mismatched expectations, one partner wants structured practice while the other just wants to chat. Katchi solves this by matching users based on intent, learning style, and study goals.

During onboarding, learners share their goals, preferred correction style, speaking ratio, and session structure. Katchi’s AI uses this to recommend partners who are equally motivated and aligned in how they want to learn.

Before each session, users receive a brief Prep Summary with shared goals and suggested topics, so both partners enter the call with clarity and purpose.

Result: More compatible matches for practice sessions that feel productive from the start.

02. AI-Driven Conversation Prompts

Many language learners struggle to keep conversations flowing when speaking with a partner. Katchi’s AI prompt assistant acts as an in-session study coach, guiding practice with structured prompts and intelligent feedback so users can focus on speaking, not planning.

Contextual Prompts on Demand

Whenever there’s a lull or the learner wants direction, they can tap the AI icon to access:

  • Recent Vocabulary: instantly bring previously saved words back into the conversation

  • Grammar-Based Prompts: practice the exact grammar patterns they’re studying

  • Situational Prompts (Role play): restaurant, travel, job interview, and other real-life scenarios

  • General AI Suggestions: topic ideas, follow-up questions, or phrasing help

Learners can keep prompts visible in a floating bottom sheet during the session or hide them when they want to focus solely on the call.

CAPABILITY 01

Goal-Aligned Partner Matching

Most language exchange apps struggle with mismatched expectations, one partner wants structured practice while the other just wants to chat. Katchi solves this by matching users based on intent, learning style, and study goals.

During onboarding, learners share their goals, preferred correction style, speaking ratio, and session structure. Katchi’s AI uses this to recommend partners who are equally motivated and aligned in how they want to learn.

Before each session, users receive a brief Prep Summary with shared goals and suggested topics, so both partners enter the call with clarity and purpose.

Result: More compatible matches for practice sessions that feel productive from the start.

CAPABILITY 02

AI-Driven Conversation Prompts

Many language learners struggle to keep conversations flowing when speaking with a partner. Katchi’s AI prompt assistant acts as an in-session study coach, guiding practice with structured prompts and intelligent feedback so users can focus on speaking, not planning.

Contextual Prompts on Demand

Whenever there’s a lull or the learner wants direction, they can tap the AI icon to access:

  • Recent Vocabulary: instantly bring previously saved words back into the conversation

  • Grammar-Based Prompts: practice the exact grammar patterns they’re studying

  • Situational Prompts (Role play): restaurant, travel, job interview, and other real-life scenarios

  • General AI Suggestions: topic ideas, follow-up questions, or phrasing help

Learners can keep prompts visible in a floating bottom sheet during the session or hide them when they want to focus solely on the call.

CAPABILITY 02

AI-Driven Conversation Prompts

Many language learners struggle to keep conversations flowing when speaking with a partner. Katchi’s AI prompt assistant acts as an in-session study coach, guiding practice with structured prompts and intelligent feedback so users can focus on speaking, not planning.

Contextual Prompts on Demand

Whenever there’s a lull or the learner wants direction, they can tap the AI icon to access:

  • Recent Vocabulary: instantly bring previously saved words back into the conversation

  • Grammar-Based Prompts: practice the exact grammar patterns they’re studying

  • Situational Prompts (Role play): restaurant, travel, job interview, and other real-life scenarios

  • General AI Suggestions: topic ideas, follow-up questions, or phrasing help

Learners can keep prompts visible in a floating bottom sheet during the session or hide them when they want to focus solely on the call.

Live AI Coach

Beyond offering prompts, Katchi includes a real-time AI coach that actively listens to the flow of the conversation. It analyzes speech patterns, grammar usage, vocabulary diversity, and opportunities for improvement.

When the AI detects:

  • a mistake worth correcting

  • a missed opportunity to use a target grammar point or vocabulary word

  • a chance to expand the conversation naturally

a small, unobtrusive AI tooltip appears.

If the user taps the tooltip, a collapsible card opens, offering a short explanation or correction, an example sentence, an optional quick practice prompt to reinforce the concept

All feedback is optional and user-driven, keeping the session natural while still providing structure when needed.

Result

AI elevates real-time conversation from passive chatting to intentional, guided practice—helping learners build accuracy, confidence, and fluency with every session.

Live AI Coach

Beyond offering prompts, Katchi includes a real-time AI coach that actively listens to the flow of the conversation. It analyzes speech patterns, grammar usage, vocabulary diversity, and opportunities for improvement.

When the AI detects:

  • a mistake worth correcting

  • a missed opportunity to use a target grammar point or vocabulary word

  • a chance to expand the conversation naturally

a small, unobtrusive AI tooltip appears.

If the user taps the tooltip, a collapsible card opens, offering a short explanation or correction, an example sentence, an optional quick practice prompt to reinforce the concept

All feedback is optional and user-driven, keeping the session natural while still providing structure when needed.

Result

AI elevates real-time conversation from passive chatting to intentional, guided practice—helping learners build accuracy, confidence, and fluency with every session.

Live AI Coach

Beyond offering prompts, Katchi includes a real-time AI coach that actively listens to the flow of the conversation. It analyzes speech patterns, grammar usage, vocabulary diversity, and opportunities for improvement.

When the AI detects:

  • a mistake worth correcting

  • a missed opportunity to use a target grammar point or vocabulary word

  • a chance to expand the conversation naturally

a small, unobtrusive AI tooltip appears.

If the user taps the tooltip, a collapsible card opens, offering a short explanation or correction, an example sentence, an optional quick practice prompt to reinforce the concept

All feedback is optional and user-driven, keeping the session natural while still providing structure when needed.

Result

AI elevates real-time conversation from passive chatting to intentional, guided practice—helping learners build accuracy, confidence, and fluency with every session.

CAPABILITY 03

AI-Powered Post Session Recap

Katchi transforms each conversation into study material you can immediately learn from. After every session, learners receive an AI-generated wrap-up designed to reinforce progress and highlight growth areas.

The recap includes:

  • Full transcript & audio replay
    A searchable transcript with speaker labels and time stamps, plus access to the session recording to revisit pronunciation and phrasing.

  • AI Summary
    Insight into what you improved, whether it’s grammar accuracy, vocabulary usage, or topic-specific fluency.

    • Key metrics at a glance
      Time spent, target-language ratio, and new words introduced during the conversation.

    • New vocabulary highlights
      Automatically extracted words from your session, paired with translations and saved for later review.

    • AI-generated corrections
      A breakdown of mistakes you made, how to fix them, and brief explanations of the grammar behind each correction.

Together, these tools turn a real-time conversation into a structured study resource—bridging the gap between casual chatting and intentional language learning.

CAPABILITY 03

Post-Session AI Recap

Katchi transforms each conversation into study material you can immediately learn from. After every session, learners receive an AI-generated wrap-up designed to reinforce progress and highlight growth areas.

The recap includes:

  • Full transcript & audio replay
    A searchable transcript with speaker labels and time stamps, plus access to the session recording to revisit pronunciation and phrasing.

  • AI Summary
    Insight into what you improved, whether it’s grammar accuracy, vocabulary usage, or topic-specific fluency.

    • Key metrics at a glance
      Time spent, target-language ratio, and new words introduced during the conversation.

    • New vocabulary highlights
      Automatically extracted words from your session, paired with translations and saved for later review.

    • AI-generated corrections
      A breakdown of mistakes you made, how to fix them, and brief explanations of the grammar behind each correction.

Together, these tools turn a real-time conversation into a structured study resource—bridging the gap between casual chatting and intentional language learning.

03. AI-Powered Post Session Recap

Katchi transforms each conversation into study material you can immediately learn from. After every session, learners receive an AI-generated wrap-up designed to reinforce progress and highlight growth areas.

The recap includes:

  • Full transcript & audio replay
    A searchable transcript with speaker labels and time stamps, plus access to the session recording to revisit pronunciation and phrasing.

  • AI Summary
    Insight into what you improved, whether it’s grammar accuracy, vocabulary usage, or topic-specific fluency.

    • Key metrics at a glance
      Time spent, target-language ratio, and new words introduced during the conversation.

    • New vocabulary highlights
      Automatically extracted words from your session, paired with translations and saved for later review.

    • AI-generated corrections
      A breakdown of mistakes you made, how to fix them, and brief explanations of the grammar behind each correction.

Together, these tools turn a real-time conversation into a structured study resource—bridging the gap between casual chatting and intentional language learning.

⑤ KEY RESULTS
A hybrid skillset on display

Katchi demonstrates how AI can amplify human potential rather than replace existing processes. By acting as a conversation coach, the AI guides learners to focus on meaningful practice without taking over the human connection at the core of learning.

This project highlights my hybrid skillset: the ability to identify a real user problem, define market-differentiating functionality, and translate that into features that drive engagement and retention, all while delivering beautiful, usable design. Even in a personal project without live data, Katchi allowed me to explore the full spectrum of product thinking and design execution, from concept validation to interaction design, demonstrating how thoughtful AI integration can enhance both experience and outcomes.

SAY ANNYEONG!