diff --git a/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPostDeleteCustomizer.java b/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPostDeleteCustomizer.java
new file mode 100644
index 00000000..2ce2a177
--- /dev/null
+++ b/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPostDeleteCustomizer.java
@@ -0,0 +1,65 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.actions.customizers;
+
+
+import java.util.List;
+import com.kingsrook.qqq.backend.core.model.actions.tables.delete.DeleteInput;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
+
+
+/*******************************************************************************
+ **
+ *******************************************************************************/
+public abstract class AbstractPostDeleteCustomizer
+{
+   protected DeleteInput deleteInput;
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public abstract List<QRecord> apply(List<QRecord> records);
+
+
+
+   /*******************************************************************************
+    ** Getter for deleteInput
+    **
+    *******************************************************************************/
+   public DeleteInput getDeleteInput()
+   {
+      return deleteInput;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for deleteInput
+    **
+    *******************************************************************************/
+   public void setDeleteInput(DeleteInput deleteInput)
+   {
+      this.deleteInput = deleteInput;
+   }
+}
diff --git a/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPostUpdateCustomizer.java b/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPostUpdateCustomizer.java
new file mode 100644
index 00000000..e3658ec0
--- /dev/null
+++ b/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPostUpdateCustomizer.java
@@ -0,0 +1,111 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.actions.customizers;
+
+
+import java.io.Serializable;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import com.kingsrook.qqq.backend.core.model.actions.tables.update.UpdateInput;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
+
+
+/*******************************************************************************
+ **
+ *******************************************************************************/
+public abstract class AbstractPostUpdateCustomizer
+{
+   protected UpdateInput   updateInput;
+   protected List<QRecord> oldRecordList;
+
+   private Map<Serializable, QRecord> oldRecordMap = null;
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public abstract List<QRecord> apply(List<QRecord> records);
+
+
+
+   /*******************************************************************************
+    ** Getter for updateInput
+    **
+    *******************************************************************************/
+   public UpdateInput getUpdateInput()
+   {
+      return updateInput;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for updateInput
+    **
+    *******************************************************************************/
+   public void setUpdateInput(UpdateInput updateInput)
+   {
+      this.updateInput = updateInput;
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public void setOldRecordList(List<QRecord> oldRecordList)
+   {
+      this.oldRecordList = oldRecordList;
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public List<QRecord> getOldRecordList()
+   {
+      return oldRecordList;
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   protected Map<Serializable, QRecord> getOldRecordMap()
+   {
+      if(oldRecordMap == null)
+      {
+         oldRecordMap = new HashMap<>();
+         for(QRecord qRecord : oldRecordList)
+         {
+            oldRecordMap.put(qRecord.getValue(updateInput.getTable().getPrimaryKeyField()), qRecord);
+         }
+      }
+
+      return (oldRecordMap);
+   }
+
+}
diff --git a/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPreDeleteCustomizer.java b/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPreDeleteCustomizer.java
new file mode 100644
index 00000000..7fa93003
--- /dev/null
+++ b/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPreDeleteCustomizer.java
@@ -0,0 +1,65 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.actions.customizers;
+
+
+import java.util.List;
+import com.kingsrook.qqq.backend.core.model.actions.tables.delete.DeleteInput;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
+
+
+/*******************************************************************************
+ **
+ *******************************************************************************/
+public abstract class AbstractPreDeleteCustomizer
+{
+   protected DeleteInput deleteInput;
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public abstract List<QRecord> apply(List<QRecord> records);
+
+
+
+   /*******************************************************************************
+    ** Getter for deleteInput
+    **
+    *******************************************************************************/
+   public DeleteInput getDeleteInput()
+   {
+      return deleteInput;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for deleteInput
+    **
+    *******************************************************************************/
+   public void setDeleteInput(DeleteInput deleteInput)
+   {
+      this.deleteInput = deleteInput;
+   }
+}
diff --git a/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/TableCustomizer.java b/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPreUpdateCustomizer.java
similarity index 59%
rename from qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/TableCustomizer.java
rename to qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPreUpdateCustomizer.java
index 4e8e22b1..ca464f08 100644
--- a/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/TableCustomizer.java
+++ b/qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPreUpdateCustomizer.java
@@ -22,29 +22,51 @@
 package com.kingsrook.qqq.backend.core.actions.customizers;
 
 
-import java.util.function.Consumer;
+import java.io.Serializable;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import com.kingsrook.qqq.backend.core.model.actions.tables.update.UpdateInput;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
 
 
 /*******************************************************************************
- ** Object used by TableCustomizers enum (and similar enums in backend modules)
- ** to assist with definition and validation of Customizers applied to tables.
+ **
  *******************************************************************************/
-public class TableCustomizer
+public abstract class AbstractPreUpdateCustomizer
 {
-   private final String           role;
-   private final Class<?>         expectedType;
-   private final Consumer<Object> validationFunction;
+   protected UpdateInput   updateInput;
+   protected List<QRecord> oldRecordList;
+
+   private Map<Serializable, QRecord> oldRecordMap = null;
 
 
 
    /*******************************************************************************
     **
     *******************************************************************************/
-   public TableCustomizer(String role, Class<?> expectedType, Consumer<Object> validationFunction)
+   public abstract List<QRecord> apply(List<QRecord> records);
+
+
+
+   /*******************************************************************************
+    ** Getter for updateInput
+    **
+    *******************************************************************************/
+   public UpdateInput getUpdateInput()
    {
-      this.role = role;
-      this.expectedType = expectedType;
-      this.validationFunction = validationFunction;
+      return updateInput;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for updateInput
+    **
+    *******************************************************************************/
+   public void setUpdateInput(UpdateInput updateInput)
+   {
+      this.updateInput = updateInput;
    }
 
 
@@ -52,43 +74,38 @@ public class TableCustomizer
    /*******************************************************************************
     **
     *******************************************************************************/
-   public TableCustomizer(String role, Class<?> expectedType)
+   public void setOldRecordList(List<QRecord> oldRecordList)
    {
-      this.role = role;
-      this.expectedType = expectedType;
-      this.validationFunction = null;
+      this.oldRecordList = oldRecordList;
    }
 
 
 
    /*******************************************************************************
-    ** Getter for role
     **
     *******************************************************************************/
-   public String getRole()
+   public List<QRecord> getOldRecordList()
    {
-      return role;
+      return oldRecordList;
    }
 
 
 
    /*******************************************************************************
-    ** Getter for expectedType
     **
     *******************************************************************************/
-   public Class<?> getExpectedType()
+   protected Map<Serializable, QRecord> getOldRecordMap()
    {
-      return expectedType;
+      if(oldRecordMap == null)
+      {
+         oldRecordMap = new HashMap<>();
+         for(QRecord qRecord : oldRecordList)
+         {
+            oldRecordMap.put(qRecord.getValue(updateInput.getTable().getPrimaryKeyField()), qRecord);
+         }
+      }
+
+      return (oldRecordMap);
    }
 
-
-
-   /*******************************************************************************
-    ** Getter for validationFunction
-    **
-    *******************************************************************************/
-   public Consumer<Object> getValidationFunction()
-   {
-      return validationFunction;
-   }
 }
diff --git a/qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPreUpdateCustomizerTest.java b/qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPreUpdateCustomizerTest.java
new file mode 100644
index 00000000..7a91d76a
--- /dev/null
+++ b/qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/actions/customizers/AbstractPreUpdateCustomizerTest.java
@@ -0,0 +1,68 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2023.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.actions.customizers;
+
+
+import java.util.List;
+import com.kingsrook.qqq.backend.core.BaseTest;
+import com.kingsrook.qqq.backend.core.context.QContext;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
+import com.kingsrook.qqq.backend.core.model.metadata.code.QCodeReference;
+import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
+import com.kingsrook.qqq.backend.core.utils.TestUtils;
+import org.junit.jupiter.api.Test;
+
+
+/*******************************************************************************
+ ** Unit test for AbstractPreUpdateCustomizer
+ *******************************************************************************/
+class AbstractPreUpdateCustomizerTest extends BaseTest
+{
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void test()
+   {
+      QTableMetaData table = QContext.getQInstance().getTable(TestUtils.TABLE_NAME_PERSON_MEMORY);
+      table.withCustomizer(TableCustomizers.PRE_UPDATE_RECORD.getRole(), new QCodeReference(PreUpdate.class));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private static class PreUpdate extends AbstractPreUpdateCustomizer
+   {
+      /*******************************************************************************
+       **
+       *******************************************************************************/
+      @Override
+      public List<QRecord> apply(List<QRecord> records)
+      {
+         return null;
+      }
+   }
+
+}
\ No newline at end of file
diff --git a/qqq-backend-module-filesystem/src/main/java/com/kingsrook/qqq/backend/module/filesystem/base/actions/AbstractPostReadFileCustomizer.java b/qqq-backend-module-filesystem/src/main/java/com/kingsrook/qqq/backend/module/filesystem/base/actions/AbstractPostReadFileCustomizer.java
new file mode 100644
index 00000000..e969e852
--- /dev/null
+++ b/qqq-backend-module-filesystem/src/main/java/com/kingsrook/qqq/backend/module/filesystem/base/actions/AbstractPostReadFileCustomizer.java
@@ -0,0 +1,37 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2023.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.module.filesystem.base.actions;
+
+
+/*******************************************************************************
+ ** after a file is read, "customize" its contents - e.g., do regex, or append
+ ** contents, or do whatever we like to it.
+ *******************************************************************************/
+public abstract class AbstractPostReadFileCustomizer
+{
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public abstract String customizeFileContents(String s);
+
+}