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 |
| TBD: Multi-domain strategy with Next.js | @gary |
| Order management in GOP | @takady |
| TBD: Global search strategy | @shinpei |
| The journey of item translation | @aymeric |
| Platform から SRE に転生！現場の声を聞きながら改善していく！ | @hatappi |
| Something about global IdP | @gia |
| TBD: GOP 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: B items integrations strategies in GOP | @ahsun |
| Guest post from FT payment platform — Engineering for Multi-Currency and Multi-Provider Payments | @ryuyama |
| TBD | @manas |
| TBD | @vb |
| TBD: GOP App Release Strategy | @manoj |
| readability; backend common packages etc | @osari.k |
| Scaling iOS Development: Building and Operating Multiple Apps in a Large-Scale Monorepo | @shingt |
| TBD: distributed transactions on checkout flow, specially error handling, retry | @ahsun |
| 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!
