diff --git a/phpstan-baseline.neon.dist b/phpstan-baseline.neon.dist
index 698fe2f56c42..0a68ece79609 100644
--- a/phpstan-baseline.neon.dist
+++ b/phpstan-baseline.neon.dist
@@ -70,36 +70,11 @@ parameters:
 			count: 1
 			path: system/Cache/Handlers/RedisHandler.php
 
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\HTTP\\\\Request\\:\\:getPost\\(\\)\\.$#"
-			count: 1
-			path: system/CodeIgniter.php
-
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\HTTP\\\\Request\\:\\:setLocale\\(\\)\\.$#"
-			count: 1
-			path: system/CodeIgniter.php
-
 		-
 			message: "#^Property CodeIgniter\\\\Database\\\\BaseBuilder\\:\\:\\$db \\(CodeIgniter\\\\Database\\\\BaseConnection\\) in empty\\(\\) is not falsy\\.$#"
 			count: 1
 			path: system/Database/BaseBuilder.php
 
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\Database\\\\BaseConnection\\:\\:_disableForeignKeyChecks\\(\\)\\.$#"
-			count: 1
-			path: system/Database/BaseConnection.php
-
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\Database\\\\BaseConnection\\:\\:_enableForeignKeyChecks\\(\\)\\.$#"
-			count: 1
-			path: system/Database/BaseConnection.php
-
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\Database\\\\QueryInterface\\:\\:getOriginalQuery\\(\\)\\.$#"
-			count: 1
-			path: system/Database/BaseConnection.php
-
 		-
 			message: "#^Negated boolean expression is always false\\.$#"
 			count: 3
@@ -115,16 +90,6 @@ parameters:
 			count: 2
 			path: system/Database/BaseResult.php
 
-		-
-			message: "#^Access to an undefined property CodeIgniter\\\\Database\\\\ConnectionInterface\\:\\:\\$DBDriver\\.$#"
-			count: 2
-			path: system/Database/Database.php
-
-		-
-			message: "#^Access to an undefined property CodeIgniter\\\\Database\\\\ConnectionInterface\\:\\:\\$connID\\.$#"
-			count: 2
-			path: system/Database/Database.php
-
 		-
 			message: "#^Property CodeIgniter\\\\Database\\\\Migration\\:\\:\\$DBGroup \\(string\\) on left side of \\?\\? is not nullable\\.$#"
 			count: 1
@@ -400,26 +365,11 @@ parameters:
 			count: 1
 			path: system/Debug/Exceptions.php
 
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\View\\\\RendererInterface\\:\\:getPerformanceData\\(\\)\\.$#"
-			count: 1
-			path: system/Debug/Toolbar/Collectors/Events.php
-
 		-
 			message: "#^Property CodeIgniter\\\\Log\\\\Logger\\:\\:\\$logCache \\(array\\) on left side of \\?\\? is not nullable\\.$#"
 			count: 1
 			path: system/Debug/Toolbar/Collectors/Logs.php
 
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\View\\\\RendererInterface\\:\\:getData\\(\\)\\.$#"
-			count: 1
-			path: system/Debug/Toolbar/Collectors/Views.php
-
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\View\\\\RendererInterface\\:\\:getPerformanceData\\(\\)\\.$#"
-			count: 2
-			path: system/Debug/Toolbar/Collectors/Views.php
-
 		-
 			message: "#^Static property CodeIgniter\\\\Email\\\\Email\\:\\:\\$func_overload \\(bool\\) in isset\\(\\) is not nullable\\.$#"
 			count: 1
@@ -565,51 +515,6 @@ parameters:
 			count: 1
 			path: system/Images/Handlers/ImageMagickHandler.php
 
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\Router\\\\RouteCollectionInterface\\:\\:getDefaultNamespace\\(\\)\\.$#"
-			count: 3
-			path: system/Router/Router.php
-
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\Router\\\\RouteCollectionInterface\\:\\:getFilterForRoute\\(\\)\\.$#"
-			count: 1
-			path: system/Router/Router.php
-
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\Router\\\\RouteCollectionInterface\\:\\:getFiltersForRoute\\(\\)\\.$#"
-			count: 1
-			path: system/Router/Router.php
-
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\Router\\\\RouteCollectionInterface\\:\\:getRoutesOptions\\(\\)\\.$#"
-			count: 1
-			path: system/Router/Router.php
-
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\Router\\\\RouteCollectionInterface\\:\\:isFiltered\\(\\)\\.$#"
-			count: 1
-			path: system/Router/Router.php
-
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\Router\\\\RouteCollectionInterface\\:\\:setHTTPVerb\\(\\)\\.$#"
-			count: 1
-			path: system/Router/Router.php
-
-		-
-			message: "#^Call to an undefined method CodeIgniter\\\\Router\\\\RouteCollectionInterface\\:\\:getRegisteredControllers\\(.*\\)\\.$#"
-			count: 2
-			path: system/Router/Router.php
-
-		-
-			message: "#^Expression on left side of \\?\\? is not nullable\\.$#"
-			count: 1
-			path: system/Router/Router.php
-
-		-
-			message: "#^Method CodeIgniter\\\\Router\\\\RouteCollectionInterface\\:\\:getRoutes\\(\\) invoked with 1 parameter, 0 required\\.$#"
-			count: 1
-			path: system/Router/Router.php
-
 		-
 			message: "#^Strict comparison using \\=\\=\\= between string and true will always evaluate to false\\.$#"
 			count: 1
@@ -675,11 +580,6 @@ parameters:
 			count: 1
 			path: system/Validation/Validation.php
 
-		-
-			message: "#^Property CodeIgniter\\\\View\\\\Cell\\:\\:\\$cache \\(CodeIgniter\\\\Cache\\\\CacheInterface\\) in empty\\(\\) is not falsy\\.$#"
-			count: 2
-			path: system/View/Cell.php
-
 		-
 			message: "#^Property Config\\\\View\\:\\:\\$plugins \\(array\\) on left side of \\?\\? is not nullable\\.$#"
 			count: 1
diff --git a/system/CodeIgniter.php b/system/CodeIgniter.php
index 1585a135c205..ebf12893e063 100644
--- a/system/CodeIgniter.php
+++ b/system/CodeIgniter.php
@@ -82,7 +82,7 @@ class CodeIgniter
     /**
      * Current request.
      *
-     * @var CLIRequest|IncomingRequest|Request|null
+     * @var CLIRequest|IncomingRequest|null
      */
     protected $request;
 
@@ -432,7 +432,10 @@ protected function handleRequest(?RouteCollectionInterface $routes, Cache $cache
             return $returnResponse ? $possibleResponse : $possibleResponse->pretend($this->useSafeOutput)->send();
         }
 
-        if ($possibleResponse instanceof Request) {
+        if (
+            $possibleResponse instanceof IncomingRequest
+            || $possibleResponse instanceof CLIRequest
+        ) {
             $this->request = $possibleResponse;
         }
 
@@ -549,9 +552,11 @@ protected function startBenchmark()
      * Sets a Request object to be used for this request.
      * Used when running certain tests.
      *
+     * @param CLIRequest|IncomingRequest $request
+     *
      * @return $this
      */
-    public function setRequest(Request $request)
+    public function setRequest($request)
     {
         $this->request = $request;
 
diff --git a/system/Config/Services.php b/system/Config/Services.php
index 169795c77a44..10f073c3e5ff 100644
--- a/system/Config/Services.php
+++ b/system/Config/Services.php
@@ -44,7 +44,6 @@
 use CodeIgniter\Log\Logger;
 use CodeIgniter\Pager\Pager;
 use CodeIgniter\Router\RouteCollection;
-use CodeIgniter\Router\RouteCollectionInterface;
 use CodeIgniter\Router\Router;
 use CodeIgniter\Security\Security;
 use CodeIgniter\Session\Handlers\Database\MySQLiHandler;
@@ -597,7 +596,7 @@ public static function routes(bool $getShared = true)
      *
      * @return Router
      */
-    public static function router(?RouteCollectionInterface $routes = null, ?Request $request = null, bool $getShared = true)
+    public static function router(?RouteCollection $routes = null, ?Request $request = null, bool $getShared = true)
     {
         if ($getShared) {
             return static::getSharedInstance('router', $routes, $request);
diff --git a/system/Database/BaseConnection.php b/system/Database/BaseConnection.php
index 4e6bcd6dfc1e..4b926b590155 100644
--- a/system/Database/BaseConnection.php
+++ b/system/Database/BaseConnection.php
@@ -914,7 +914,7 @@ public function prepare(Closure $func, array $options = [])
 
         $this->pretend(false);
 
-        if ($sql instanceof QueryInterface) {
+        if ($sql instanceof Query) {
             $sql = $sql->getOriginalQuery();
         }
 
@@ -1509,6 +1509,13 @@ public function disableForeignKeyChecks()
         return $this->query($sql);
     }
 
+    /**
+     * Returns platform-specific SQL to disable foreign key checks.
+     *
+     * @return string
+     */
+    abstract protected function _disableForeignKeyChecks();
+
     /**
      * Enables foreign key checks temporarily.
      */
@@ -1519,6 +1526,13 @@ public function enableForeignKeyChecks()
         return $this->query($sql);
     }
 
+    /**
+     * Returns platform-specific SQL to enable foreign key checks.
+     *
+     * @return string
+     */
+    abstract protected function _enableForeignKeyChecks();
+
     /**
      * Allows the engine to be set into a mode where queries are not
      * actually executed, but they are still generated, timed, etc.
diff --git a/system/Database/Database.php b/system/Database/Database.php
index 0d3c26c2e84b..4c0b068e5c41 100644
--- a/system/Database/Database.php
+++ b/system/Database/Database.php
@@ -61,7 +61,7 @@ public function load(array $params = [], string $alias = '')
     /**
      * Creates a Forge instance for the current database type.
      */
-    public function loadForge(ConnectionInterface $db): object
+    public function loadForge(BaseConnection $db): object
     {
         if (! $db->connID) {
             $db->initialize();
@@ -73,7 +73,7 @@ public function loadForge(ConnectionInterface $db): object
     /**
      * Creates a Utils instance for the current database type.
      */
-    public function loadUtils(ConnectionInterface $db): object
+    public function loadUtils(BaseConnection $db): object
     {
         if (! $db->connID) {
             $db->initialize();
diff --git a/system/Debug/Toolbar/Collectors/Events.php b/system/Debug/Toolbar/Collectors/Events.php
index a8a7e7aa4c35..510821e5e1da 100644
--- a/system/Debug/Toolbar/Collectors/Events.php
+++ b/system/Debug/Toolbar/Collectors/Events.php
@@ -11,7 +11,7 @@
 
 namespace CodeIgniter\Debug\Toolbar\Collectors;
 
-use CodeIgniter\View\RendererInterface;
+use CodeIgniter\View\View;
 use Config\Services;
 
 /**
@@ -54,7 +54,7 @@ class Events extends BaseCollector
     /**
      * Instance of the Renderer service
      *
-     * @var RendererInterface
+     * @var View
      */
     protected $viewer;
 
diff --git a/system/Debug/Toolbar/Collectors/Views.php b/system/Debug/Toolbar/Collectors/Views.php
index fae3385fffbc..3144e87a6d53 100644
--- a/system/Debug/Toolbar/Collectors/Views.php
+++ b/system/Debug/Toolbar/Collectors/Views.php
@@ -11,7 +11,7 @@
 
 namespace CodeIgniter\Debug\Toolbar\Collectors;
 
-use CodeIgniter\View\RendererInterface;
+use CodeIgniter\View\View;
 use Config\Services;
 
 /**
@@ -62,7 +62,7 @@ class Views extends BaseCollector
     /**
      * Instance of the Renderer service
      *
-     * @var RendererInterface
+     * @var View
      */
     protected $viewer;
 
diff --git a/system/HTTP/Request.php b/system/HTTP/Request.php
index 6294295db4df..00df6abe9966 100644
--- a/system/HTTP/Request.php
+++ b/system/HTTP/Request.php
@@ -98,7 +98,7 @@ public function getMethod(bool $upper = false): string
     /**
      * Sets the request method. Used when spoofing the request.
      *
-     * @return Request
+     * @return $this
      *
      * @deprecated Use withMethod() instead for immutability
      *
diff --git a/system/Model.php b/system/Model.php
index 59fbef240668..6a3076421dfd 100644
--- a/system/Model.php
+++ b/system/Model.php
@@ -156,8 +156,8 @@ public function setTable(string $table)
 
     /**
      * Fetches the row of database from $this->table with a primary key
-     * matching $id. This methods works only with dbCalls
-     * This methods works only with dbCalls
+     * matching $id.
+     * This method works only with dbCalls
      *
      * @param bool                  $singleton Single or multiple results
      * @param array|int|string|null $id        One primary key or an array of primary keys
@@ -189,7 +189,7 @@ protected function doFind(bool $singleton, $id = null)
 
     /**
      * Fetches the column of database from $this->table
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      *
      * @param string $columnName Column Name
      *
@@ -197,13 +197,15 @@ protected function doFind(bool $singleton, $id = null)
      */
     protected function doFindColumn(string $columnName)
     {
-        return $this->select($columnName)->asArray()->find();
+        $this->select($columnName);
+
+        return $this->asArray()->find();
     }
 
     /**
      * Works with the current Query Builder instance to return
      * all results, while optionally limiting them.
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      *
      * @param int $limit  Limit
      * @param int $offset Offset
@@ -226,7 +228,7 @@ protected function doFindAll(int $limit = 0, int $offset = 0)
     /**
      * Returns the first row of the result set. Will take any previous
      * Query Builder calls into account when determining the result set.
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      *
      * @return array|object|null
      */
@@ -251,7 +253,7 @@ protected function doFirst()
 
     /**
      * Inserts data into the current table.
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      *
      * @param array $data Data
      *
@@ -314,7 +316,7 @@ protected function doInsert(array $data)
 
     /**
      * Compiles batch insert strings and runs the queries, validating each row prior.
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      *
      * @param array|null $set       An associative array of insert values
      * @param bool|null  $escape    Whether to escape values
@@ -340,7 +342,7 @@ protected function doInsertBatch(?array $set = null, ?bool $escape = null, int $
 
     /**
      * Updates a single record in $this->table.
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      *
      * @param array|int|string|null $id
      * @param array|null            $data
@@ -366,7 +368,7 @@ protected function doUpdate($id = null, $data = null): bool
 
     /**
      * Compiles an update string and runs the query
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      *
      * @param array|null  $set       An associative array of update values
      * @param string|null $index     The where key
@@ -385,7 +387,7 @@ protected function doUpdateBatch(?array $set = null, ?string $index = null, int
     /**
      * Deletes a single record from $this->table where $id matches
      * the table's primaryKey
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      *
      * @param array|int|string|null $id    The rows primary key(s)
      * @param bool                  $purge Allows overriding the soft deletes setting.
@@ -430,7 +432,7 @@ protected function doDelete($id = null, bool $purge = false)
     /**
      * Permanently deletes all rows that have been marked as deleted
      * through soft deletes (deleted = 1)
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      *
      * @return bool|mixed
      */
@@ -444,7 +446,7 @@ protected function doPurgeDeleted()
     /**
      * Works with the find* methods to return only the rows that
      * have been deleted.
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      */
     protected function doOnlyDeleted()
     {
@@ -453,7 +455,7 @@ protected function doOnlyDeleted()
 
     /**
      * Compiles a replace into string and runs the query
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      *
      * @param array|null $data      Data
      * @param bool       $returnSQL Set to true to return Query String
@@ -469,7 +471,7 @@ protected function doReplace(?array $data = null, bool $returnSQL = false)
      * Grabs the last error(s) that occurred from the Database connection.
      * The return array should be in the following format:
      *  ['source' => 'message']
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      *
      * @return array<string,string>
      */
@@ -523,7 +525,7 @@ public function getIdValue($data)
      * Loops over records in batches, allowing you to operate on them.
      * Works with $this->builder to get the Compiled select to
      * determine the rows to operate on.
-     * This methods works only with dbCalls
+     * This method works only with dbCalls
      *
      * @throws DataException
      */
diff --git a/system/Router/Router.php b/system/Router/Router.php
index c653608d08c3..aec3ec68d82f 100644
--- a/system/Router/Router.php
+++ b/system/Router/Router.php
@@ -20,12 +20,12 @@
 /**
  * Request router.
  */
-class Router implements RouterInterface
+class Router
 {
     /**
      * A RouteCollection instance.
      *
-     * @var RouteCollectionInterface
+     * @var RouteCollection
      */
     protected $collection;
 
@@ -118,7 +118,7 @@ class Router implements RouterInterface
     /**
      * Stores a reference to the RouteCollection object.
      */
-    public function __construct(RouteCollectionInterface $routes, ?Request $request = null)
+    public function __construct(RouteCollection $routes, ?Request $request = null)
     {
         $this->collection = $routes;
 
@@ -126,7 +126,7 @@ public function __construct(RouteCollectionInterface $routes, ?Request $request
         $this->controller = $this->collection->getDefaultController();
         $this->method     = $this->collection->getDefaultMethod();
 
-        $this->collection->setHTTPVerb(strtolower($request->getMethod() ?? $_SERVER['REQUEST_METHOD']));
+        $this->collection->setHTTPVerb(strtolower($request->getMethod()));
 
         $this->translateURIDashes = $this->collection->shouldTranslateURIDashes();
 
diff --git a/system/Test/FeatureTestCase.php b/system/Test/FeatureTestCase.php
index dc0c65b4a8b7..fce81efffd36 100644
--- a/system/Test/FeatureTestCase.php
+++ b/system/Test/FeatureTestCase.php
@@ -342,9 +342,9 @@ protected function setupHeaders(IncomingRequest $request)
      *
      * @throws ReflectionException
      *
-     * @return Request
+     * @return IncomingRequest
      */
-    protected function populateGlobals(string $method, Request $request, ?array $params = null)
+    protected function populateGlobals(string $method, IncomingRequest $request, ?array $params = null)
     {
         // $params should set the query vars if present,
         // otherwise set it from the URL.
@@ -371,8 +371,10 @@ protected function populateGlobals(string $method, Request $request, ?array $par
      *
      * @param array|null $params The parameters to be formatted and put in the body. If this is empty, it will get the
      *                           what has been loaded into the request global of the request class.
+     *
+     * @return IncomingRequest
      */
-    protected function setRequestBody(Request $request, ?array $params = null): Request
+    protected function setRequestBody(IncomingRequest $request, ?array $params = null): Request
     {
         if (isset($this->requestBody) && $this->requestBody !== '') {
             $request->setBody($this->requestBody);
diff --git a/system/Test/Mock/MockConnection.php b/system/Test/Mock/MockConnection.php
index 2d95b496aab8..ed8e09a5d103 100644
--- a/system/Test/Mock/MockConnection.php
+++ b/system/Test/Mock/MockConnection.php
@@ -238,4 +238,14 @@ protected function _transRollback(): bool
     {
         return true;
     }
+
+    protected function _disableForeignKeyChecks()
+    {
+        return '';
+    }
+
+    protected function _enableForeignKeyChecks()
+    {
+        return '';
+    }
 }
diff --git a/system/View/Cell.php b/system/View/Cell.php
index c4fa23a6fbba..81e111e719be 100644
--- a/system/View/Cell.php
+++ b/system/View/Cell.php
@@ -75,7 +75,7 @@ public function render(string $library, $params = null, int $ttl = 0, ?string $c
             ? $cacheName
             : str_replace(['\\', '/'], '', $class) . $method . md5(serialize($params));
 
-        if (! empty($this->cache) && $output = $this->cache->get($cacheName)) {
+        if ($output = $this->cache->get($cacheName)) {
             return $output;
         }
 
@@ -129,7 +129,7 @@ public function render(string $library, $params = null, int $ttl = 0, ?string $c
             $output = $instance->{$method}(...array_values($fireArgs));
         }
         // Can we cache it?
-        if (! empty($this->cache) && $ttl !== 0) {
+        if ($ttl !== 0) {
             $this->cache->save($cacheName, $output, $ttl);
         }