Service Definition
SantaDays is a personal advent tree that friends fill one day at a time. When someone leaves a message through your tree’s link, a space for that day fills in. Messages arrive from the 1st through the 24th of each month, and the tree’s owner can open them all at midnight on the 25th, Korea Standard Time. It brings the anticipation of Christmas into every month.
The Problem
It can be hard to find a moment to tell someone you appreciate them. SantaDays gives friends a reason to leave a short note and gives the recipient a day to read a month’s worth of messages together. Senders only need a link. Recipients watch their tree fill up while the messages stay sealed until opening day.
Core Targets
- Friends, partners and families who want to collect small notes from one another
- School friends and clubs who share their trees and leave each other words of encouragement
- People who enjoy waiting for letters and want that feeling every month, beyond birthdays and the holiday season
Core User Flow
- Create your tree: sign in with Google and choose a personal address.
- Share it with friends: send your tree’s link. Friends can leave messages without signing in.
- Fill one space per day: each day you receive a message from the 1st through the 24th fills one space. Multiple messages on the same day still count as one.
- Open your messages on the 25th: from midnight KST, only you can read what you received.
- Claim a completion gift: fill all 24 spaces to apply for that month’s mobile voucher between the 25th and the last day of the month. Completion gifts are currently for users in South Korea, with a limited quantity available each month on a first-come basis.
Key Features
- A personal tree and shareable address where friends come to leave their messages
- Messages without sign-in so friends can take part straight from the link
- A monthly opening day with an inbox that holds messages until it is time to read them
- Seasonal scenery with changing trees and backgrounds, plus a share card after opening
- Five languages: Korean, English, Japanese, Simplified Chinese and Traditional Chinese
Service Design
- Messages stay with their recipient: visitors can see the tree’s spaces and message count. Message contents and sender names are not public.
- Count days, not messages: progress comes from receiving messages on different days, rather than collecting as many as possible at once.
- One opening time: the server uses Korea Standard Time to decide when messages can be written and opened.
- Safer messages: moderation checks for abuse and either masks offending words or hides the message when it is opened.
Tech Stack
- Web: Next.js 15 App Router, React 19, TypeScript
- Data: Cloud SQL PostgreSQL
- Identity and files: Firebase Auth, Firebase Storage
- Hosting: Firebase App Hosting