December 2025 | Added 5 New Problems (System Design & Practical Format)

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Overview

As of December 15, 2025, we have added a total of 5 new problems: 3 System Design problems and 2 Practical Format problems. Alongside this addition, we have also revised the requirements for Practical Format problems to improve the accuracy of evaluating practical skills.

Changes

System Design (3 problems)

  • Push Notification Delivery Service Design: A problem focused on designing a system for large-scale delivery of push notifications to mobile apps.
  • Text Sharing Service Design: A problem focused on designing a service similar to Pastebin, where text snippets are shared via URLs.
  • Nearby Event Bulletin Board Service Design: A problem focused on designing a service that uses location information to provide information about nearby events.

Practical Format (2 problems)

  • Point Transfer UI Implementation (Vue.js): A problem to implement the frontend UI for a point transfer function using Vue.js.
  • Balance Management API Implementation (Go): A problem to implement an API server with account balance management functionality using Go.

Notes

For the Practical Format problems introduced this time, we have increased the level of abstraction in the problem requirements and reduced the amount of detailed specifications. This challenges candidates to interpret and make judgments about specifications themselves, allowing for a more realistic assessment of engineers' abilities in a practical setting. The newly added problems are available for immediate use.