How JD Finance Built Its HarmonyOS NEXT App: Architecture, Challenges, and Solutions

Background

At Huawei Developer Conference in June, Huawei announced the beta upgrade of HarmonyOS NEXT for developers and early adopters, with commercial release planned for Q4 2024. By September, over 10,000 apps and services were listed in the HarmonyOS NEXT market, and Huawei invested more than CNY 6 billion to incentivize developers, growing the developer community to 6.75 million.

HarmonyOS NEXT is built on OpenHarmony, removes AOSP support and the Linux kernel, and runs only on the HarmonyOS kernel, eliminating Android compatibility and reducing redundant code by 40%, resulting in higher performance, energy efficiency, and security.

JD Finance HarmonyOS Release

JD Finance began researching HarmonyOS NEXT in November 2023 and launched a trial version in June. After three quarters of effort, the official 6.9.30 version was released on September 19, leveraging native HarmonyOS capabilities, system‑level AI, and intent framework to understand user intents and provide personalized services across devices.

Why a HarmonyOS version?

Huawei phone users constitute the largest share of JD Finance’s non‑iOS active users, many of whom are due for device upgrades. HarmonyOS NEXT’s launch presents both risk (potential loss of users if not adapted) and opportunity (first‑mover advantage, high‑value business users).

Feature Scope

Given the app’s size (200+ native/Roma pages, 3400+ H5 pages with PV>100), the team prioritized core functionalities. In the September release, 21 major modules covering ~90% of the online app’s capabilities were delivered.

Overall Architecture

The app is divided into a Infrastructure layer (network, routing, data monitoring, web container, Roma framework, etc.) and a Business layer (native pages, Roma cross‑platform pages, H5 pages). Business logic runs inside containers (Roma, H5, mini‑program), allowing minimal changes when adapting to a new OS.

Infrastructure layer : provides foundational services such as networking, routing, encryption, image loading, web container, Roma framework.

Business layer : implements user‑facing features using native, Roma, or H5 pages.

Technical Solution Comparison

Three migration paths were evaluated:

Option 1 : Pure native HarmonyOS implementation – highest stability, lowest risk, but requires rewriting all pages.

Option 2 (short‑term) : Use Roma cross‑platform for most pages, retaining some native code – moderate risk and effort.

Option 3 (long‑term) : Full Roma with custom rendering – lowest future adaptation cost but highest technical difficulty and cost.

The final decision combined Option 2 as the primary path with selective research on Option 3.

Infrastructure Component Construction

Necessary components (high priority) such as routing, network library, encrypted channels, image loading, web container, and Roma framework were built first, followed by non‑essential components (lower priority) like SGM, analytics, sharing, and H5 offline support. Over 30 core components were delivered, including a Lego‑style framework, push, QR scanning, long‑connection, Lottie, storage, permission control, and unified configuration.

Key Challenges

ArkTS lacks dynamic language features, making some implementations complex.

ArkUI is declarative, requiring a shift from imperative UI thinking.

Early HarmonyOS APIs and tooling were unstable.

New concepts such as intent framework and meta‑services needed time to master.

Cross‑team dependencies required careful schedule coordination.

Release Timeline

A trial version was pushed to 1 million invited users after the June developer conference, using native ArkUI and H5 due to incomplete Roma support. The trial demonstrated the first HarmonyOS native app on the JD platform and gained product exposure.

Business‑Side Development

The app adopts a hybrid model: native pages, Roma cross‑platform pages, and H5 pages. H5 pages interact with native capabilities via a jsbridge; the bridge was updated to recognize HarmonyOS. Critical pages (e.g., large‑image viewer, login) were kept native for performance and complexity reasons.

New HarmonyOS Features Utilized

Huawei Account Service for one‑click login.

Intelligent PhotoPicker for fast selection of ID documents.

Intent framework enabling voice‑activated queries (e.g., “show JD consumption details”).

Final Release and Post‑Launch Tasks

Before market submission, the team addressed two urgent issues:

Foldable screen adaptation : scaled UI components by 1.2× to meet Huawei’s requirements.

Performance optimization : reduced UI hierarchy depth, moved heavy logic to worker threads, and off‑loaded slow system APIs to background threads, achieving 88% of scenes meeting the S‑grade benchmark.

Additional compliance steps included separate software copyright registration, MIIT ICP filing for HarmonyOS, and updating privacy policies to reference HarmonyOS identifiers.

Future Plans

Remaining features (~10% gap) will be iteratively added. The team will continue exploring HarmonyOS ecosystem innovations such as meta‑services, service cards, and AI integration to drive user acquisition, activation, and cost reduction.

Conclusion

The HarmonyOS NEXT migration required a complete rewrite of the JD Finance app, extensive collaboration with Huawei, and the creation of over 700 issue reports that helped improve the OS. The experience is being shared as a series of technical articles covering UI adaptation, infrastructure, engineering practices, new feature usage, and performance tuning.