Here I will note some advanced maintanace stuff for Redmi 9c smartphone.
SETTINGS
1. Testing menu. *#*#4636#*#* ( *#*#INFO#*#* )
2. EngineerMode *#*#3646633#*#*
DEBLOATING SHIZUKU+CANTA
1. What Canta recommended to delete:
Now I am debloating Redmi 9NFC.
com.miui.touchassistant Accesso rapido The floating "Quick Ball" menu.
com.xiaomi.calendar Agenda Xiaomi Calendar.
com.miui.analitics System-level telemetry and tracking. While invasive, MIUI hardcodes deep dependencies into these. Removing them breaks the built-in "Security" app or triggers endless black screen loops. MIUI telemetry and data collection.
com.android.egg eastern egg The interactive hidden easter egg game of your Android version.
com.mi.android.globalminusscreen App vault App Vault (the widget screen filled with promotional content when you swipe left on your home screen). (App Vault / Glance): The left-swipe screen that shows useless news and ads. Highly recommended to remove.
com.mediatek.atmwifimeta Hardware verification suite for factory Wi-Fi testing.
com.miui.audioeffect
com.mediatek.autodialer Background automated dialer used for automated phone call network stressing tests.
com.miui.backup Local and Cloud backup tools.
com.miui.cloudbackup Local and Cloud backup tools.
com.xiaomi.bttester BTCIT Quality control menus used on assembly lines to verify buttons, screens, and Bluetooth radios.
com.wapi.wapicertmanager
com.android.theme.color.cinnamon
com.miui.cit Quality control menus used on assembly lines to verify buttons, screens, and Bluetooth radios.
com.longcheertel.cit Quality control menus used on assembly lines to verify buttons, screens, and Bluetooth radios.
com.miui.weather2 MIUI Weather app.
com.miui.cloudservice.sysbase Mi Cloud System Base. Core background service for Mi Cloud. Removing it can crash the Settings app or break Mi Account login.
com.android.providers.partnerbookmarks Pre-saved promotional web bookmarks hardcoded into browsers.
com.android.systemui.overlay.miui The visual layer that applies MIUI over the core Android framework. Deleting this will cause immediate crashes and an unrecoverable bootloop.
com.google.android.feedback Standard Android bug and crash report pipeline to Google servers.
com.google.android.aoos.restore Temporary configuration routines meant to execute only during your very first device boot.
com.miui.qr Built-in QR code scanner.
com.debug.loggerui Automated system loggers intended for developers to catch software bugs. They only waste battery.
com.wdstechnology.android.kryten Legacy enterprise corporate application package. Redundant for retail users.
com.xiaomi.scanner Mi Scanner app.
com.mediatek.emcamera Raw barebones diagnostic interface for the MediaTek camera sensor.
com.mediatek.engineermode MediaTek Engineer Mode for raw hardware calibration and factory testing.
com.miui.hybrid Xiaomi's "Quick Apps" ecosystem. It opens cloud apps without installing them, heavily used by Xiaomi to push sponsored web games and banner ads. A hidden framework that runs "instant apps" without installing them. It is notorious for showing ads and running in the background.
com.facebook.system Hidden Facebook background services installed out of the box that harvest data and force background updates even if the main Facebook app is uninstalled.
com.facebook.appmanager Hidden Facebook background services installed out of the box that harvest data and force background updates even if the main Facebook app is uninstalled.
com.facebook.services Hidden Facebook background services installed out of the box that harvest data and force background updates even if the main Facebook app is uninstalled.
com.miui.bugreport User bug submission portal to Xiaomi and the clipboard's canned phrases manager. MIUI bug reporting tool.
com.focaltech.fingerprint Hardware-level driver for your physical fingerprint scanner.
com.miui.phrase User bug submission portal to Xiaomi and the clipboard's canned phrases manager. Frequent phrases / clipboard manager.
com.xiaomi.location.fused Fuses GPS, Wi-Fi, and cellular data to calculate location accurately. Deleting this completely breaks GPS tracking.
com.xiaomi.glgm Mi Game Center. An alternative app store pushing spam game listings.
com.xiaomi.mipics Wallpaper Carousel. Continually cycles lock-screen backgrounds while tracking telemetry and burning cellular data.
com.google.android.onetimeinitializer Temporary configuration routines meant to execute only during your very first device boot.
com.android.theme.color.green
com.google.android.gms.location.history Logs your continuous background movements to Google Maps servers.
com.google.ar.lens Standalone shortcut for Google Lens. Redundant if you open Lens through your camera or search bar.
com.mediatek.lbs.em2.ui MediaTek Engineer Mode for raw hardware calibration and factory testing.
com.miui.vsimcore Virtual SIM service for eSIM configurations. The Redmi 9 NFC only handles physical micro-SIMs, making this code dead weight.
com.xiaomi.payment Ecosystem links for Mi Pay. Completely obsolete in global markets where Google Wallet is standard.
com.xiaomi.mi_connect_service Ecosystem links for Mi Pay. Completely obsolete in global markets where Google Wallet is standard.
com.mipay.wallet.in Ecosystem links for Mi Pay. Completely obsolete in global markets where Google Wallet is standard.
com.miui.videoplayer Notorious for injecting ads into your video player.
com.miui.micloudsync Mi Cloud sync service.
com.miui.daemon System-level telemetry and tracking. While invasive, MIUI hardcodes deep dependencies into these. Removing them breaks the built-in "Security" app or triggers endless black screen loops. MIUI Background Daemon. Collects system stats and manages memory. Note: Removing this stops background telemetry and saves battery, but on some older MIUI versions, it can make the OS slightly more aggressive at killing background apps. It is generally safe and recommended to remove for privacy.
com.miui.msa.global "MIUI System Ads". This is the primary process responsible for pushing ads into stock apps like the File Manager and Theme store. Delete this first. (MSA - MIUI System Ads): THE MOST IMPORTANT ONE. This is the core engine that serves ads in MIUI system apps. Removing it kills 90% of system ads.
com.android.theme.color.ocean
com.miui.yelowpage Business identification catalog built directly into the caller application. Useless outside of Asia.
android.autoinstalls.config.Xiaomi.model Triggers auto-downloads of sponsored partner applications during your initial device activation.
com.miui.fm
com.android.traceur Automated system loggers intended for developers to catch software bugs. They only waste battery.
com.android.theme.icon_pack.rounded.systemui SystemUI Icon Packs. If you remove these while they are active, SystemUI will crash. (Only safe if you are 100% sure you are using the "Default" theme, but it's safer to just leave them).
com.longcheertel.sarauth Internal verification app for SAR (Specific Absorption Rate) radiation homologation.
com.fingerprints.sensortesttool Laboratory utility used to test the fingerprint physical module.
com.xiaomi.simactivate.service The Xiaomi SIM activation and validation service. Without it, you may lose cellular network signals or mobile data capabilities.
com.miui.fmservice
com.miui.miservice
com.xiaomi.midrop
com.miui.hybrid.accessory Xiaomi's "Quick Apps" ecosystem. It opens cloud apps without installing them, heavily used by Xiaomi to push sponsored web games and banner ads. Companion to Quick Apps.
com.tencent.soter.soterserver A biometric encryption framework required by several banking apps and mobile wallets for secure digital authentication.
com.android.theme.color.space
com.android.theme.icon.square SystemUI Icon Packs. If you remove these while they are active, SystemUI will crash. (Only safe if you are 100% sure you are using the "Default" theme, but it's safer to just leave them).
com.miui.hybrid.accessory
com.xiaomi.upnp
com.verizon.remoteSimlock Remote locking protocol used by US network carrier Verizon. Out of place on your global model.
com.miui.wmsvc Secondary window management service for MIUI. High risk of UI freezes if deleted.
com.xiaomi.xmsfkeeper A persistence service keeping Xiaomi push notifications alive in the background. Critical to prevent system-wide notification freezing.
com.mediatek.ygps Low-level MediaTek GPS raw calibration tool.
com.google.android.youtube