Extending a Japanese 1st-party ads system to the US market

01: BACKGROUND

1st-party ads, from Japan to the US

A 1st-party ads system running for the Japanese market was strategically slated for expansion into the US, to establish ad operations independent of 3rd-party ads. A Delta Quest member led the technical design and implementation as frontend lead.

02: CHALLENGE

Currencies, time zones, and per-market feature flags

Supporting different currencies and time zones, and managing feature flags per market, were the main technical challenges — all while continuing new feature development for the Japanese market and keeping the impact of the US rollout to a minimum.

03: APPROACH

Extend, don't rebuild — release behind flags

Rather than rebuilding, the existing system was extended so JP/US functionality could be switched flexibly. Feature flags kept each market's releases independent, allowing a controlled, staged launch. After launch, impact was measured through internal dashboards, Google Analytics, and user interviews, with continuous improvement via A/B testing.

stack: React · TypeScript · feature flag operations · A/B testing

04: RESULT

120% adoption, 200% ad revenue — JP development uninterrupted

Initial user adoption reached 120% of target and ad revenue 200% of forecast, while new feature development for the Japanese market continued in parallel with the successful US rollout.