Network requests like GET and POST affect app speed and battery. Slow or large requests can cause UI delays and drop frames below 60fps. Excessive memory use happens if responses are large or not handled well. Battery drains faster with frequent or heavy data transfers.
Use asynchronous calls with Kotlin coroutines to avoid blocking the main thread. Cache responses when possible to reduce network calls. Compress request and response data to save bandwidth. Limit request size and avoid unnecessary data. Use efficient JSON parsing libraries. Cancel requests if the user navigates away.
Network code libraries like Retrofit or OkHttp add a few MBs to the app size, usually under 5MB. Keep dependencies minimal to avoid bloating. Startup time is mostly unaffected unless you preload data synchronously. Lazy load data after startup to keep app launch fast.
Android uses libraries like OkHttp and Retrofit for HTTP calls. iOS uses URLSession. Both support async calls and background transfers. Android requires INTERNET permission in the manifest; iOS requires App Transport Security settings for non-HTTPS. Error handling and retry logic differ slightly due to platform APIs.
Probably the app is making synchronous network calls on the main thread, blocking UI rendering. Or it is loading large data without caching or pagination. Another cause could be uncompressed or excessive data transfer causing slow responses.