Design an In‑Seat Personal Entertainment System (IFE) — UI/Interaction-Focused System Design

Context

You are designing a seatback personal entertainment system for a commercial aircraft. Assume:

• Each seat has a dedicated client device (touchscreen, limited compute, local storage) connected to an on‑aircraft cabin network with intermittent and limited satellite backhaul to the internet.
• Content is primarily served from onboard servers; safety‑critical systems are isolated.
• The system must be usable during turbulence, handle fast power cycles/reboots, and support a multilingual, global passenger base.

Requirements

1. UI/Interaction Flows
   • Browse/search the catalog (movies, TV, music, games).
   • Start/resume playback; playback controls (seek, pause/play) and persistence across reboots.
   • Captions/subtitles, audio language selection, audio descriptions.
   • Volume/brightness controls and behavior with cabin announcements.
   • Games (single‑player, no internet dependency).
   • Purchases/paywalls (e.g., premium content, Wi‑Fi passes) with offline settlement.
2. Non‑Functional UX
   • Responsiveness under intermittent/limited bandwidth and occasional network partitions.
   • Input modalities: touch, physical buttons, and hand‑held remote.
   • Accessibility: screen reader, high contrast, large text, color contrast, cognitive load.
   • Parental controls/kids mode and content rating enforcement.
   • Multi‑language UI and content metadata; RTL support.
3. Client Architecture
   • Rendering stack, state management, offline caching strategy, and background prefetching.
   • Fault isolation between UI and media playback pipeline.
4. Cabin/Ground Integration
   • Communication with onboard services (content delivery, license/DRM, ads scheduler, crew notifications/PA integration).
   • Ground content updates and ad campaign delivery.
5. Security & Reliability
   • DRM/content protection end‑to‑end.
   • Fault tolerance, watchdogs, and quick reboot UX.
6. Experimentation & Telemetry
   • A/B testing approach that works offline and respects safety constraints.
   • Telemetry for performance (QoE) and UX, buffering and upload strategy given limited backhaul.

Deliverable

Describe your design, focusing on:

• Key user journeys and interaction details.
• Offline‑first responsiveness techniques.
• Input/accessibility/multi‑language design choices.
• Client architecture (rendering, state, caching) and media pipeline.
• Onboard/ground service interactions (updates, ads, notifications).
• DRM/security, fault tolerance, fast reboot experience.
• A/B experimentation and telemetry.

Make reasonable assumptions explicit and justify trade‑offs briefly.