diff --git a/cloud/aws/rds_serverless/debug.tf b/cloud/aws/rds_serverless/debug.tf
index 7a285f2..fdd17f0 100644
--- a/cloud/aws/rds_serverless/debug.tf
+++ b/cloud/aws/rds_serverless/debug.tf
@@ -1,27 +1,64 @@
 resource "local_file" "debug" {
   content = nonsensitive(jsonencode({
     rds = {
-      instance_name         = var.instance_name,
-      tennants              = var.tenants,
-      application_arn       = try(var.application.arn, null),
-      application_name      = try(var.application.name, null),
-      engine_user           = var.engine,
-      engine_actual         = data.aws_rds_engine_version.latest[var.engine_version].engine
-      engine_version_actual = data.aws_rds_engine_version.latest[var.engine_version].version,
-      endpoints = {
-        write = aws_rds_cluster_endpoint.endpoint["write"].endpoint,
-        read  = aws_rds_cluster_endpoint.endpoint["read"].endpoint
+      instance_name    = var.instance_name,
+      tennants         = var.tenants,
+      application_arn  = try(var.application.arn, null),
+      application_name = try(var.application.name, null),
+      engine = {
+        requested = {
+          engine  = var.engine,
+          version = var.engine_version
+        }
+        resolved = {
+          engine  = data.aws_rds_engine_version.latest[var.engine_version].engine,
+          version = data.aws_rds_engine_version.latest[var.engine_version].version,
+          match   = data.aws_rds_engine_version.latest,
+        }
       }
+      #endpoints = {
+      #  write = aws_rds_cluster_endpoint.endpoint["write"].endpoint,
+      #  read  = aws_rds_cluster_endpoint.endpoint["read"].endpoint
+      #}
       admin = {
         username = local.admin_username
         password = local.admin_password
       }
     }
-    tenants = {
-      input  = var.tenants
-      output = local.output_tenants
-    }
+    tenants = var.tenants
   }))
-  filename        = "${path.root}/.debug/aws/rds/serverless/${var.instance_name}.json"
+  filename        = "${path.root}/.debug/aws/rds/serverless/${var.instance_name}.provided.json"
+  file_permission = "0600"
+}
+resource "local_file" "debug_result" {
+  content = nonsensitive(jsonencode({
+    rds = {
+      instance_name    = var.instance_name,
+      tennants         = var.tenants,
+      application_arn  = try(var.application.arn, null),
+      application_name = try(var.application.name, null),
+      engine = {
+        requested = {
+          engine  = var.engine,
+          version = var.engine_version
+        }
+        resolved = {
+          engine  = data.aws_rds_engine_version.latest[var.engine_version].engine,
+          version = data.aws_rds_engine_version.latest[var.engine_version].version,
+          match   = data.aws_rds_engine_version.latest[var.engine_version],
+        }
+      }
+      endpoints = {
+        write = aws_rds_cluster_endpoint.endpoint["write"].endpoint,
+        read  = aws_rds_cluster_endpoint.endpoint["read"].endpoint
+      }
+    }
+    tenants = merge({ admin = {
+      username = local.admin_username
+      password = local.admin_password
+    } }, local.output_tenants)
+
+  }))
+  filename        = "${path.root}/.debug/aws/rds/serverless/${var.instance_name}.result.json"
   file_permission = "0600"
 }
\ No newline at end of file
diff --git a/cloud/aws/rds_serverless/inputs.tf b/cloud/aws/rds_serverless/inputs.tf
index 2d6cbc3..209ff33 100644
--- a/cloud/aws/rds_serverless/inputs.tf
+++ b/cloud/aws/rds_serverless/inputs.tf
@@ -5,8 +5,6 @@ variable "instance_name" {
 }
 locals {
   sanitised_name = lower(replace(var.instance_name, "[^a-zA-Z0-9]", "-"))
-  titled_name    = replace(title(join(" ", split("-", local.sanitised_name))), " ", "")
-  app_name       = try(var.application.name, local.titled_name)
 }
 variable "tenants" {
   type = map(object({
@@ -26,24 +24,56 @@ variable "application" {
   })
   default = null
 }
-variable "aws_profile" {
-  type        = string
-  description = "AWS profile to use for generating RDS auth token"
-  default     = null
-}
 
 variable "engine" {
   type        = string
-  description = "The database engine to use"
+  description = "The database engine to use. This must be either aurora-mysql or aurora-postgresql"
   default     = "aurora-mysql"
   validation {
     error_message = "Must be either aurora-mysql or aurora-postgresql"
     condition     = contains(["aurora-mysql", "aurora-postgresql"], var.engine)
   }
 }
+locals {
+  is_mysql        = var.engine == "aurora-mysql"
+  is_postgres     = var.engine == "aurora-postgresql"
+  supported_mysql = ["5.7", "8.0"]
+  supported_postgres = [
+    "11.9", "11.21",
+    "12.9", "12.11", "12.12", "12.13", "12.14", "12.15", "12.16", "12.17", "12.18", "12.19", "12.20", "12.22",
+    "13.7", "13.8", "13.9", "13.10", "13.11", "13.12", "13.12", "13.13", "13.14", "13.15", "13.16", "13.18",
+    "14.3", "14.4", "14.5", "14.6", "14.7", "14.8", "14.9", "14.10", "14.11", "14.12", "14.13", "14.15",
+    "15.2", "15.3", "15.4", "15.5", "15.6", "15.7", "15.8", "15.10",
+    "16.1", "16.2", "16.3", "16.4", "16.6",
+  ]
+  engines_supporting_local_write_forwarding ={
+    "aurora-mysql"        = ["8.0"]
+    "aurora-postgresql"   = [
+      "14.13", "14.15",
+      "15.8", "15.10",
+      "16.4", "16.6",
+    ]
+  }
+  # MB: This is a hack until I get my patch into terraform's aws provider: https://github.com/hashicorp/terraform-provider-aws/pull/40700
+  supports_local_write_forwarding = (
+    local.is_mysql && contains(local.engines_supporting_local_write_forwarding.aurora-mysql, local.engine_version)||
+    local.is_postgres && contains(local.engines_supporting_local_write_forwarding.aurora-postgresql, local.engine_version)
+  )
+}
 variable "engine_version" {
   type    = string
-  default = "8.0"
+  default = null
+  validation {
+    error_message = "If the engine is mysql_aurora, the engine_version must be one of ${join(", ", local.supported_mysql)}."
+    condition     = local.is_mysql ? contains(local.supported_mysql, var.engine_version) : true
+  }
+  validation {
+    error_message = "If the engine is aurora-postgresql, the engine_version must be one of ${join(", ", local.supported_postgres)}."
+    condition     = local.is_postgres ? contains(local.supported_postgres, var.engine_version) : true
+  }
+}
+locals {
+  engine_version = var.engine_version != null ? var.engine_version : "8.0"
 }
 
 variable "scaling" {
@@ -69,6 +99,12 @@ variable "scaling" {
   }
 }
 
+locals {
+  scaling = merge(var.scaling, {
+    min_capacity = local.is_mysql && var.engine_version == "5.7" && var.scaling.min_capacity == 0 ? 1 : var.scaling.min_capacity
+  })
+}
+
 variable "backup_window" {
   type        = string
   description = "The daily time range during which automated backups are created if automated backups are enabled."
diff --git a/cloud/aws/rds_serverless/rds.tf b/cloud/aws/rds_serverless/rds.tf
index 9f62d33..b74e8a2 100644
--- a/cloud/aws/rds_serverless/rds.tf
+++ b/cloud/aws/rds_serverless/rds.tf
@@ -30,7 +30,7 @@ resource "aws_rds_cluster" "cluster" {
   master_username                     = local.admin_username
   master_password                     = local.admin_password
   storage_encrypted                   = true
-  enable_local_write_forwarding       = true
+  enable_local_write_forwarding       = local.supports_local_write_forwarding
   backup_retention_period             = var.backup_retention_period_days
   skip_final_snapshot                 = var.skip_final_snapshot
   preferred_backup_window             = var.backup_window
@@ -41,13 +41,16 @@ resource "aws_rds_cluster" "cluster" {
   vpc_security_group_ids              = [aws_security_group.rds.id]
 
   serverlessv2_scaling_configuration {
-    max_capacity = var.scaling.max_capacity
-    min_capacity = var.scaling.min_capacity
+    max_capacity = local.scaling.max_capacity
+    min_capacity = local.scaling.min_capacity
   }
 
   lifecycle {
     create_before_destroy = false
-    replace_triggered_by  = [data.aws_rds_engine_version.latest]
+    precondition {
+      error_message = "If you're using mysql 5.7, min_capacity must be greater or equal to 1, because it doesn't support auto-pause."
+      condition     = local.is_mysql && var.engine_version == "5.7" ? local.scaling.min_capacity >= 1 : true
+    }
   }
 
   tags = merge(
@@ -56,7 +59,6 @@ resource "aws_rds_cluster" "cluster" {
       Name = var.instance_name
     }
   )
-
 }
 
 data "aws_rds_certificate" "default" {
diff --git a/cloud/aws/rds_serverless/tenant/db.tf b/cloud/aws/rds_serverless/tenant/db.tf
index edf7de9..745cfa7 100644
--- a/cloud/aws/rds_serverless/tenant/db.tf
+++ b/cloud/aws/rds_serverless/tenant/db.tf
@@ -1,5 +1,4 @@
 locals {
-  is_mysql = var.engine == "aurora-mysql"
   db_tunnel_remote = {
     host = data.aws_rds_cluster.cluster.endpoint
     port = local.is_mysql ? 3306 : 5432
diff --git a/cloud/aws/rds_serverless/tenant/input.tf b/cloud/aws/rds_serverless/tenant/input.tf
index 21dd935..eb47633 100644
--- a/cloud/aws/rds_serverless/tenant/input.tf
+++ b/cloud/aws/rds_serverless/tenant/input.tf
@@ -32,29 +32,11 @@ locals {
   database = lower(var.database)
   password = try(random_password.password[0].result, var.password)
 }
-variable "app_name" {
-  type        = string
-  description = "The application name"
-}
-
 variable "tags" {
   type        = map(string)
   description = "Tags to apply to resources"
   default     = {}
 }
-variable "aws_profile" {
-  type        = string
-  description = "AWS profile to use for generating RDS auth token"
-  default     = null
-}
-variable "is_active" {
-  type    = bool
-  default = true
-}
-variable "super_user_iam_role_name" {
-  type    = string
-  default = null
-}
 variable "engine" {
   type        = string
   description = "The engine type of the RDS cluster"
@@ -63,6 +45,10 @@ variable "engine" {
     condition     = var.engine == "aurora-postgres" || var.engine == "aurora-mysql"
   }
 }
+locals {
+  is_mysql    = var.engine == "aurora-mysql"
+  is_postgres = var.engine == "aurora-postgres"
+}
 variable "mysql_binary" {
   type        = string
   description = "The path to the mysql binary"
diff --git a/cloud/aws/rds_serverless/tenants.tf b/cloud/aws/rds_serverless/tenants.tf
index b2a632b..b4bea22 100644
--- a/cloud/aws/rds_serverless/tenants.tf
+++ b/cloud/aws/rds_serverless/tenants.tf
@@ -4,9 +4,7 @@ module "tenants" {
   source         = "./tenant"
   username       = each.value.username
   database       = each.value.database
-  app_name       = local.app_name
   vpc_id         = data.aws_vpc.current.id
-  aws_profile    = var.aws_profile
   cluster_id     = aws_rds_cluster.cluster.id
   engine         = aws_rds_cluster.cluster.engine
   admin_username = local.admin_username