Ark-Pets is a desktop pet application that renders Arknights (ζζ₯ζΉθ) character models as an always-on-top, interactive window overlay. It uses a dual-process architecture: a JavaFX launcher (DesktopLauncher) manages model downloads, configuration, and updates, while a separate libGDX core process (EmbeddedLauncher) handles real-time Spine animation rendering, physics simulation (gravity, friction, repulsion), and an AI-driven behavior state machine. The two processes communicate via a custom socket-based IPC layer, enabling the launcher to control multiple pet instances and relay system tray commands. The application targets Windows primarily, with experimental support for macOS and Linux via platform-specific window control stubs. The launcher provides a full GUI for browsing and filtering model datasets, configuring behavior probabilities, adjusting rendering quality, and managing telemetry preferences. The core rendering pipeline uses libGDX with OpenGL, custom GLSL shaders for outlines and shadows, and a Spine runtime for skeletal animations. Animation selection is driven by a stochastic matrix and transition system with configurable easing functions. Telemetry is opt-in and uses a write-ahead log (WAL) for reliable crash and performance data collection, optionally forwarded to Sentry. External dependencies include JavaFX 17, libGDX, Spine runtime, FastJSON2, log4j (reload4j), JNA (for Windows window control), and Sentry SDK. The build system is Gradle with multi-module setup (core and desktop), and CI workflows build JARs, ZIPs, and Windows installers via Inno Setup. The codebase demonstrates strong engineering practices with clean abstractions in animation transitions, caching, network source strategies, and GUI component builders, though some areas show brittleness (animation name parsing) and platform-specific gaps.