Hello. I’m @deeeeet from Cross Border (XB) Engineering.
On September 30, 2025, we announced a new strategy for our cross-border business and launched Mercari’s first globally unified app, the “Mercari Global App” (hereinafter referred to as the Global App).
This time, we’re launching a new series that takes you behind the scenes of our global app development projects.
Stay tuned for topics spanning not just backend development, but also mobile development, web development, SRE & Enabling, and much more.
Global App overview
The Mercari Global App will enable overseas buyers to browse and purchase items from Mercari and Mercari Shops in Japan. The Global App solves problems related to language, payment, and complicated procedures, providing overseas buyers with an easy, safe, and secure shopping experience similar to that of Mercari in Japan.
The Global App will be available in Taiwan and Hong Kong starting from September 30th, 2025, and is planned to gradually expand to more countries and regions in the future.
Publishing schedule
Following is a collection of links to each article. I recommend bookmarking this page for the prompt update, and it will be very useful if you want to check it out at a later date.
| Title | Author |
|---|---|
| Rebuilding Foundation for Global Expansion | @deeeet |
| Behind the Infrastructure Powering Global Expansion | @yanolab |
| From Local to Global: Building Seamless B2C Product Integration at Mercari | @ahsun |
| Order management in Mercari Global Marketplace | @takady |
| TBD: Global search strategy | @shinpei |
| The Journey of User-Generated Content Translation | @aymeric |
| Behind the Scenes of SRE Supporting the Global Web — An Improvement Approach to Accelerate Development | @hatappi |
| Something about global IdP | @gia |
| TBD: Global App Android strategy and execution and all in between | @Karthi |
| Mirrord + E2E testing | @ryotarai |
| TBD: How we overcome Project management challenges (How to plan a product launch in 6 months) | @g-bansal |
| TBD: Multi-domain strategy with Next.js | @gary |
| Guest post from FT payment platform — Engineering for Multi-Currency and Multi-Provider Payments | @ryuyama |
| TBD | @manas |
| TBD | @vb |
| How We Deliver Mobile App Updates Faster | @manoj |
| readability; backend common packages etc | @osari.k |
| Evolving Mercari’s iOS codebase into a multi-product monorepo | @shingt |
| TBD: Framework for handling i18n resources in web modular monorepo | @gary |
| TBD: Order (Double Master Data Migration); ItemxTransaction (decoupling using sagas/external locking) | @andrei |
| Something about global payment and checkout | @huhu |
| TBD: Ops development with AI | @waiting.lau |
| Taming Agents in the Mercari Web Monorepo | @maxi |
| Sync Saga | @Shishir |
| TBD: High output teams | @Atif |
| TBD: Ordering Features | @Shreyasi |
| TBD | @Chong (チョン) |
| TBD | @chris |
If any of these articles catch your interest, bookmark this page or follow and check out the official X account for engineers!
