diff --git a/apex/androidmk.go b/apex/androidmk.go
index d612f1e..80237fb 100644
--- a/apex/androidmk.go
+++ b/apex/androidmk.go
@@ -103,6 +103,18 @@
 		return moduleNames
 	}
 
+	var postInstallCommands []string
+	for _, fi := range a.filesInfo {
+		if a.linkToSystemLib && fi.transitiveDep && fi.availableToPlatform() {
+			// TODO(jiyong): pathOnDevice should come from fi.module, not being calculated here
+			linkTarget := filepath.Join("/system", fi.path())
+			linkPath := filepath.Join(a.installDir.ToMakePath().String(), apexBundleName, fi.path())
+			mkdirCmd := "mkdir -p " + filepath.Dir(linkPath)
+			linkCmd := "ln -sfn " + linkTarget + " " + linkPath
+			postInstallCommands = append(postInstallCommands, mkdirCmd, linkCmd)
+		}
+	}
+
 	seenDataOutPaths := make(map[string]bool)
 
 	for _, fi := range a.filesInfo {
@@ -176,8 +188,6 @@
 			// we will have duplicated notice entries.
 			fmt.Fprintln(w, "LOCAL_NO_NOTICE_FILE := true")
 		}
-		fmt.Fprintln(w, "LOCAL_SOONG_INSTALLED_MODULE :=", filepath.Join(modulePath, fi.stem()))
-		fmt.Fprintln(w, "LOCAL_SOONG_INSTALL_PAIRS :=", fi.builtFile.String()+":"+filepath.Join(modulePath, fi.stem()))
 		fmt.Fprintln(w, "LOCAL_PREBUILT_MODULE_FILE :=", fi.builtFile.String())
 		fmt.Fprintln(w, "LOCAL_MODULE_CLASS :=", fi.class.nameInMake())
 		if fi.module != nil {
@@ -287,10 +297,18 @@
 					if len(patterns) > 0 {
 						fmt.Fprintln(w, "LOCAL_OVERRIDES_MODULES :=", strings.Join(patterns, " "))
 					}
+					if len(a.compatSymlinks) > 0 {
+						// For flattened apexes, compat symlinks are attached to apex_manifest.json which is guaranteed for every apex
+						postInstallCommands = append(postInstallCommands, a.compatSymlinks...)
+					}
 				}
 
 				// File_contexts of flattened APEXes should be merged into file_contexts.bin
 				fmt.Fprintln(w, "LOCAL_FILE_CONTEXTS :=", a.fileContexts)
+
+				if len(postInstallCommands) > 0 {
+					fmt.Fprintln(w, "LOCAL_POST_INSTALL_CMD :=", strings.Join(postInstallCommands, " && "))
+				}
 			}
 			fmt.Fprintln(w, "include $(BUILD_PREBUILT)")
 		}
@@ -371,8 +389,6 @@
 				}
 				fmt.Fprintln(w, "LOCAL_MODULE_STEM :=", name+stemSuffix)
 				fmt.Fprintln(w, "LOCAL_UNINSTALLABLE_MODULE :=", !a.installable())
-				fmt.Fprintln(w, "LOCAL_SOONG_INSTALLED_MODULE :=", a.installedFile.String())
-				fmt.Fprintln(w, "LOCAL_SOONG_INSTALL_PAIRS :=", a.outputFile.String()+":"+a.installedFile.String())
 
 				// Because apex writes .mk with Custom(), we need to write manually some common properties
 				// which are available via data.Entries
@@ -397,6 +413,16 @@
 					fmt.Fprintln(w, "LOCAL_REQUIRED_MODULES +=", strings.Join(a.requiredDeps, " "))
 				}
 				a.writeRequiredModules(w, name)
+				var postInstallCommands []string
+				if a.prebuiltFileToDelete != "" {
+					postInstallCommands = append(postInstallCommands, "rm -rf "+
+						filepath.Join(a.installDir.ToMakePath().String(), a.prebuiltFileToDelete))
+				}
+				// For unflattened apexes, compat symlinks are attached to apex package itself as LOCAL_POST_INSTALL_CMD
+				postInstallCommands = append(postInstallCommands, a.compatSymlinks...)
+				if len(postInstallCommands) > 0 {
+					fmt.Fprintln(w, "LOCAL_POST_INSTALL_CMD :=", strings.Join(postInstallCommands, " && "))
+				}
 
 				if a.mergedNotices.Merged.Valid() {
 					fmt.Fprintln(w, "LOCAL_NOTICE_FILE :=", a.mergedNotices.Merged.Path().String())
diff --git a/apex/apex.go b/apex/apex.go
index 0bc48be..33188cb 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -399,14 +399,14 @@
 	// vendor/google/build/build_unbundled_mainline_module.sh for more detail.
 	bundleModuleFile android.WritablePath
 
-	// Target directory to install this APEX. Usually out/target/product/<device>/<partition>/apex.
+	// Target path to install this APEX. Usually out/target/product/<device>/<partition>/apex.
 	installDir android.InstallPath
 
-	// Path where this APEX was installed.
-	installedFile android.InstallPath
-
-	// Installed locations of symlinks for backward compatibility.
-	compatSymlinks android.InstallPaths
+	// List of commands to create symlinks for backward compatibility. These commands will be
+	// attached as LOCAL_POST_INSTALL_CMD to apex package itself (for unflattened build) or
+	// apex_manifest (for flattened build) so that compat symlinks are always installed
+	// regardless of TARGET_FLATTEN_APEX setting.
+	compatSymlinks []string
 
 	// Text file having the list of individual files that are included in this APEX. Used for
 	// debugging purpose.
@@ -431,10 +431,6 @@
 	modulePaths []string
 }
 
-func (*apexBundle) InstallBypassMake() bool {
-	return true
-}
-
 // apexFileClass represents a type of file that can be included in APEX.
 type apexFileClass int
 
@@ -2090,9 +2086,7 @@
 		a.linkToSystemLib = false
 	}
 
-	if a.properties.ApexType != zipApex {
-		a.compatSymlinks = makeCompatSymlinks(a.BaseModuleName(), ctx, a.primaryApexType)
-	}
+	a.compatSymlinks = makeCompatSymlinks(a.BaseModuleName(), ctx)
 
 	////////////////////////////////////////////////////////////////////////////////////////////
 	// 4) generate the build rules to create the APEX. This is done in builder.go.
diff --git a/apex/builder.go b/apex/builder.go
index 4b0ac0c..e22d694 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -823,55 +823,47 @@
 		a.outputFile = signedCompressedOutputFile
 	}
 
-	installSuffix := suffix
-	if a.isCompressed {
-		installSuffix = imageCapexSuffix
-	}
-
 	// Install to $OUT/soong/{target,host}/.../apex.
-	a.installedFile = ctx.InstallFile(a.installDir, a.Name()+installSuffix, a.outputFile,
-		a.compatSymlinks.Paths()...)
+	ctx.InstallFile(a.installDir, a.Name()+suffix, a.outputFile)
 
 	// installed-files.txt is dist'ed
 	a.installedFilesFile = a.buildInstalledFilesFile(ctx, a.outputFile, imageDir)
 }
 
+// Context "decorator", overriding the InstallBypassMake method to always reply `true`.
+type flattenedApexContext struct {
+	android.ModuleContext
+}
+
+func (c *flattenedApexContext) InstallBypassMake() bool {
+	return true
+}
+
 // buildFlattenedApex creates rules for a flattened APEX. Flattened APEX actually doesn't have a
 // single output file. It is a phony target for all the files under /system/apex/<name> directory.
 // This function creates the installation rules for the files.
 func (a *apexBundle) buildFlattenedApex(ctx android.ModuleContext) {
 	bundleName := a.Name()
-	installedSymlinks := append(android.InstallPaths(nil), a.compatSymlinks...)
 	if a.installable() {
 		for _, fi := range a.filesInfo {
 			dir := filepath.Join("apex", bundleName, fi.installDir)
-			installDir := android.PathForModuleInstall(ctx, dir)
-			if a.linkToSystemLib && fi.transitiveDep && fi.availableToPlatform() {
-				// TODO(jiyong): pathOnDevice should come from fi.module, not being calculated here
-				pathOnDevice := filepath.Join("/system", fi.path())
-				installedSymlinks = append(installedSymlinks,
-					ctx.InstallAbsoluteSymlink(installDir, fi.stem(), pathOnDevice))
-			} else {
-				target := ctx.InstallFile(installDir, fi.stem(), fi.builtFile)
-				for _, sym := range fi.symlinks {
-					installedSymlinks = append(installedSymlinks,
-						ctx.InstallSymlink(installDir, sym, target))
-				}
+			target := ctx.InstallFile(android.PathForModuleInstall(ctx, dir), fi.stem(), fi.builtFile)
+			for _, sym := range fi.symlinks {
+				ctx.InstallSymlink(android.PathForModuleInstall(ctx, dir), sym, target)
 			}
 		}
-
-		// Create install rules for the files added in GenerateAndroidBuildActions after
-		// buildFlattenedApex is called.  Add the links to system libs (if any) as dependencies
-		// of the apex_manifest.pb file since it is always present.
-		dir := filepath.Join("apex", bundleName)
-		installDir := android.PathForModuleInstall(ctx, dir)
-		ctx.InstallFile(installDir, "apex_manifest.pb", a.manifestPbOut, installedSymlinks.Paths()...)
-		ctx.InstallFile(installDir, "apex_pubkey", a.publicKeyFile)
 	}
 
 	a.fileContexts = a.buildFileContexts(ctx)
 
-	a.outputFile = android.PathForModuleInstall(ctx, "apex", bundleName)
+	// Temporarily wrap the original `ctx` into a `flattenedApexContext` to have it reply true
+	// to `InstallBypassMake()` (thus making the call `android.PathForModuleInstall` below use
+	// `android.pathForInstallInMakeDir` instead of `android.PathForOutput`) to return the
+	// correct path to the flattened APEX (as its contents is installed by Make, not Soong).
+	// TODO(jiyong): Why do we need to set outputFile for flattened APEX? We don't seem to use
+	// it and it actually points to a path that can never be built. Remove this.
+	factx := flattenedApexContext{ctx}
+	a.outputFile = android.PathForModuleInstall(&factx, "apex", bundleName)
 }
 
 // getCertificateAndPrivateKey retrieves the cert and the private key that will be used to sign
diff --git a/apex/prebuilt.go b/apex/prebuilt.go
index 5b070c6..61e7a0b 100644
--- a/apex/prebuilt.go
+++ b/apex/prebuilt.go
@@ -17,13 +17,11 @@
 import (
 	"fmt"
 	"io"
-	"path/filepath"
 	"strconv"
 	"strings"
 
 	"android/soong/android"
 	"android/soong/java"
-
 	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
 )
@@ -55,17 +53,18 @@
 
 	installDir      android.InstallPath
 	installFilename string
-	installedFile   android.InstallPath
 	outputApex      android.WritablePath
 
 	// A list of apexFile objects created in prebuiltCommon.initApexFilesForAndroidMk which are used
 	// to create make modules in prebuiltCommon.AndroidMkEntries.
 	apexFilesForAndroidMk []apexFile
 
-	// Installed locations of symlinks for backward compatibility.
-	compatSymlinks android.InstallPaths
+	// list of commands to create symlinks for backward compatibility.
+	// these commands will be attached as LOCAL_POST_INSTALL_CMD
+	compatSymlinks []string
 
-	hostRequired []string
+	hostRequired        []string
+	postInstallCommands []string
 }
 
 type sanitizedPrebuilt interface {
@@ -224,10 +223,13 @@
 				func(ctx android.AndroidMkExtraEntriesContext, entries *android.AndroidMkEntries) {
 					entries.SetString("LOCAL_MODULE_PATH", p.installDir.ToMakePath().String())
 					entries.SetString("LOCAL_MODULE_STEM", p.installFilename)
-					entries.SetPath("LOCAL_SOONG_INSTALLED_MODULE", p.installedFile)
-					entries.SetString("LOCAL_SOONG_INSTALL_PAIRS", p.outputApex.String()+":"+p.installedFile.String())
 					entries.SetBoolIfTrue("LOCAL_UNINSTALLABLE_MODULE", !p.installable())
 					entries.AddStrings("LOCAL_OVERRIDES_MODULES", p.prebuiltCommonProperties.Overrides...)
+					postInstallCommands := append([]string{}, p.postInstallCommands...)
+					postInstallCommands = append(postInstallCommands, p.compatSymlinks...)
+					if len(postInstallCommands) > 0 {
+						entries.SetString("LOCAL_POST_INSTALL_CMD", strings.Join(postInstallCommands, " && "))
+					}
 					p.addRequiredModules(entries)
 				},
 			},
@@ -257,9 +259,6 @@
 		ExtraEntries: []android.AndroidMkExtraEntriesFunc{
 			func(ctx android.AndroidMkExtraEntriesContext, entries *android.AndroidMkEntries) {
 				entries.SetString("LOCAL_MODULE_PATH", p.installDir.ToMakePath().String())
-				entries.SetString("LOCAL_SOONG_INSTALLED_MODULE :=", filepath.Join(p.installDir.String(), fi.stem()))
-				entries.SetString("LOCAL_SOONG_INSTALL_PAIRS :=",
-					fi.builtFile.String()+":"+filepath.Join(p.installDir.String(), fi.stem()))
 
 				// soong_java_prebuilt.mk sets LOCAL_MODULE_SUFFIX := .jar  Therefore
 				// we need to remove the suffix from LOCAL_MODULE_STEM, otherwise
@@ -472,10 +471,6 @@
 	inputApex android.Path
 }
 
-func (p *Prebuilt) InstallBypassMake() bool {
-	return true
-}
-
 type ApexFileProperties struct {
 	// the path to the prebuilt .apex file to import.
 	//
@@ -761,15 +756,15 @@
 	// Save the files that need to be made available to Make.
 	p.initApexFilesForAndroidMk(ctx)
 
-	// in case that prebuilt_apex replaces source apex (using prefer: prop)
-	p.compatSymlinks = makeCompatSymlinks(p.BaseModuleName(), ctx, true)
-	// or that prebuilt_apex overrides other apexes (using overrides: prop)
-	for _, overridden := range p.prebuiltCommonProperties.Overrides {
-		p.compatSymlinks = append(p.compatSymlinks, makeCompatSymlinks(overridden, ctx, true)...)
+	if p.installable() {
+		ctx.InstallFile(p.installDir, p.installFilename, p.inputApex)
 	}
 
-	if p.installable() {
-		p.installedFile = ctx.InstallFile(p.installDir, p.installFilename, p.inputApex, p.compatSymlinks.Paths()...)
+	// in case that prebuilt_apex replaces source apex (using prefer: prop)
+	p.compatSymlinks = makeCompatSymlinks(p.BaseModuleName(), ctx)
+	// or that prebuilt_apex overrides other apexes (using overrides: prop)
+	for _, overridden := range p.prebuiltCommonProperties.Overrides {
+		p.compatSymlinks = append(p.compatSymlinks, makeCompatSymlinks(overridden, ctx)...)
 	}
 }
 
@@ -969,10 +964,10 @@
 	}
 
 	// in case that apex_set replaces source apex (using prefer: prop)
-	a.compatSymlinks = makeCompatSymlinks(a.BaseModuleName(), ctx, true)
+	a.compatSymlinks = makeCompatSymlinks(a.BaseModuleName(), ctx)
 	// or that apex_set overrides other apexes (using overrides: prop)
 	for _, overridden := range a.prebuiltCommonProperties.Overrides {
-		a.compatSymlinks = append(a.compatSymlinks, makeCompatSymlinks(overridden, ctx, true)...)
+		a.compatSymlinks = append(a.compatSymlinks, makeCompatSymlinks(overridden, ctx)...)
 	}
 }
 
diff --git a/apex/vndk.go b/apex/vndk.go
index cf525a8..75c0fb0 100644
--- a/apex/vndk.go
+++ b/apex/vndk.go
@@ -15,6 +15,7 @@
 package apex
 
 import (
+	"path/filepath"
 	"strings"
 
 	"android/soong/android"
@@ -95,14 +96,11 @@
 }
 
 // name is module.BaseModuleName() which is used as LOCAL_MODULE_NAME and also LOCAL_OVERRIDES_*
-func makeCompatSymlinks(name string, ctx android.ModuleContext, primaryApex bool) (symlinks android.InstallPaths) {
+func makeCompatSymlinks(name string, ctx android.ModuleContext) (symlinks []string) {
 	// small helper to add symlink commands
-	addSymlink := func(target string, dir android.InstallPath, linkName string) {
-		if primaryApex {
-			symlinks = append(symlinks, ctx.InstallAbsoluteSymlink(dir, linkName, target))
-		} else {
-			symlinks = append(symlinks, dir.Join(ctx, linkName))
-		}
+	addSymlink := func(target, dir, linkName string) {
+		link := filepath.Join(dir, linkName)
+		symlinks = append(symlinks, "mkdir -p "+dir+" && rm -rf "+link+" && ln -sf "+target+" "+link)
 	}
 
 	// TODO(b/142911355): [VNDK APEX] Fix hard-coded references to /system/lib/vndk
@@ -120,15 +118,14 @@
 		// the name of vndk apex is formatted "com.android.vndk.v" + version
 		apexName := vndkApexNamePrefix + vndkVersion
 		if ctx.Config().Android64() {
-			dir := android.PathForModuleInPartitionInstall(ctx, "system", "lib64")
-			addSymlink("/apex/"+apexName+"/lib64", dir, "vndk-sp-"+vndkVersion)
-			addSymlink("/apex/"+apexName+"/lib64", dir, "vndk-"+vndkVersion)
+			addSymlink("/apex/"+apexName+"/lib64", "$(TARGET_OUT)/lib64", "vndk-sp-"+vndkVersion)
+			addSymlink("/apex/"+apexName+"/lib64", "$(TARGET_OUT)/lib64", "vndk-"+vndkVersion)
 		}
 		if !ctx.Config().Android64() || ctx.DeviceConfig().DeviceSecondaryArch() != "" {
-			dir := android.PathForModuleInPartitionInstall(ctx, "system", "lib")
-			addSymlink("/apex/"+apexName+"/lib", dir, "vndk-sp-"+vndkVersion)
-			addSymlink("/apex/"+apexName+"/lib", dir, "vndk-"+vndkVersion)
+			addSymlink("/apex/"+apexName+"/lib", "$(TARGET_OUT)/lib", "vndk-sp-"+vndkVersion)
+			addSymlink("/apex/"+apexName+"/lib", "$(TARGET_OUT)/lib", "vndk-"+vndkVersion)
 		}
+		return
 	}
 
 	// http://b/121248172 - create a link from /system/usr/icu to
@@ -136,25 +133,19 @@
 	// A symlink can't overwrite a directory and the /system/usr/icu directory once
 	// existed so the required structure must be created whatever we find.
 	if name == "com.android.i18n" {
-		dir := android.PathForModuleInPartitionInstall(ctx, "system", "usr")
-		addSymlink("/apex/com.android.i18n/etc/icu", dir, "icu")
+		addSymlink("/apex/com.android.i18n/etc/icu", "$(TARGET_OUT)/usr", "icu")
+		return
 	}
 
 	// TODO(b/124106384): Clean up compat symlinks for ART binaries.
-	if name == "com.android.art" {
-		dir := android.PathForModuleInPartitionInstall(ctx, "system", "bin")
-		addSymlink("/apex/com.android.art/bin/dalvikvm", dir, "dalvikvm")
+	if name == "com.android.art" || strings.HasPrefix(name, "com.android.art.") {
+		addSymlink("/apex/com.android.art/bin/dalvikvm", "$(TARGET_OUT)/bin", "dalvikvm")
 		dex2oat := "dex2oat32"
 		if ctx.Config().Android64() {
 			dex2oat = "dex2oat64"
 		}
-		addSymlink("/apex/com.android.art/bin/"+dex2oat, dir, "dex2oat")
-	} else if name == "com.android.art" || strings.HasPrefix(name, "com.android.art.") {
-		dir := android.PathForModuleInPartitionInstall(ctx, "system", "bin")
-		symlinks = append(symlinks,
-			dir.Join(ctx, "dalvikvm"),
-			dir.Join(ctx, "dex2oat"))
+		addSymlink("/apex/com.android.art/bin/"+dex2oat, "$(TARGET_OUT)/bin", "dex2oat")
+		return
 	}
-
-	return symlinks
+	return
 }