diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 8a04a22..12f4ea0 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -9,27 +9,22 @@
 name: Java CI with Maven
 
 on:
-  push:
-    branches: [ "main" ]
   pull_request:
     branches: [ "main" ]
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v4
-    - name: Set up JDK 25
-      uses: actions/setup-java@v4
-      with:
-        java-version: '25'
-        distribution: 'temurin'
-        cache: maven
-    - name: Build with Maven
-      run: mvn -B package --file pom.xml
+      - uses: actions/checkout@v4
+
+      - name: Set up JDK
+        uses: actions/setup-java@v4
+        with:
+          java-version: '25'
+          distribution: 'temurin'
+          cache: maven
 
-    # Optional: Uploads the full dependency graph to GitHub to improve the quality of Dependabot alerts this repository can receive
-    - name: Update dependency graph
-      uses: advanced-security/maven-dependency-submission-action@571e99aab1055c2e71a1e2309b9691de18d6b7d6
+      - name: Build
+        run: mvn -B package
\ No newline at end of file
diff --git a/src/main/java/org/example/alfs/entities/Attachment.java b/src/main/java/org/example/alfs/entities/Attachment.java
index 022797e..53bf491 100644
--- a/src/main/java/org/example/alfs/entities/Attachment.java
+++ b/src/main/java/org/example/alfs/entities/Attachment.java
@@ -20,8 +20,10 @@ public class Attachment {
     @GeneratedValue
     private Long id;
 
+    @Column(nullable = false)
     private String fileName;
 
+    @Column(nullable = false)
     private String s3Key;
 
     private LocalDateTime uploadedAt;
diff --git a/src/main/java/org/example/alfs/entities/AuditLog.java b/src/main/java/org/example/alfs/entities/AuditLog.java
index eabd823..103bc9e 100644
--- a/src/main/java/org/example/alfs/entities/AuditLog.java
+++ b/src/main/java/org/example/alfs/entities/AuditLog.java
@@ -2,6 +2,7 @@
 
 import jakarta.persistence.*;
 import lombok.*;
+import org.example.alfs.enums.AuditAction;
 
 import java.time.LocalDateTime;
 
@@ -22,7 +23,9 @@ public class AuditLog {
     @GeneratedValue
     private Long id;
 
-    private String action;
+    @Enumerated(EnumType.STRING)
+    @Column(nullable = false, length = 50)
+    private AuditAction action;
 
     private String fieldName;
 
diff --git a/src/main/java/org/example/alfs/entities/Ticket.java b/src/main/java/org/example/alfs/entities/Ticket.java
index 55f3ff9..4498445 100644
--- a/src/main/java/org/example/alfs/entities/Ticket.java
+++ b/src/main/java/org/example/alfs/entities/Ticket.java
@@ -2,6 +2,7 @@
 
 import jakarta.persistence.*;
 import lombok.*;
+import org.example.alfs.enums.TicketStatus;
 
 
 import java.time.LocalDateTime;
@@ -24,25 +25,45 @@ public class Ticket {
     @GeneratedValue
     private Long id;
 
+    @Column(nullable = false, length = 255)
     private String title;
 
+    @Lob
+    @Basic(fetch = FetchType.LAZY)
     private String description;
 
-    private String status;
+    @Enumerated(EnumType.STRING)
+    @Column(nullable = false, length = 32)
+    private TicketStatus status;
 
     @Column(nullable = false, unique = true, length = 128, updatable = false)
     private String reporterToken;
 
     private LocalDateTime createdAt;
 
+    private LocalDateTime updatedAt;
+
     @PrePersist
     public void prePersist() {
         createdAt = LocalDateTime.now();
+        if (status == null) {
+            status = TicketStatus.OPEN;
+        }
+    }
+
+    @PreUpdate
+    public void preUpdate() {
+        updatedAt = LocalDateTime.now();
     }
 
     @OneToMany(mappedBy = "ticket", cascade = CascadeType.ALL, orphanRemoval = true)
     private List<Attachment> attachments;
 
-    @ManyToOne
-    private User assignedHandler;
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "reporter_id", nullable = true)  // null if anonymous
+    private User reporter;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "investigator_id", nullable = true)
+    private User investigator;
 }
diff --git a/src/main/java/org/example/alfs/entities/TicketComment.java b/src/main/java/org/example/alfs/entities/TicketComment.java
index 93d0027..7c8063a 100644
--- a/src/main/java/org/example/alfs/entities/TicketComment.java
+++ b/src/main/java/org/example/alfs/entities/TicketComment.java
@@ -11,7 +11,7 @@
 The comments are written by a User.
  */
 @Entity
-@Table(name="ticket_comment")
+@Table(name = "ticket_comment")
 @Getter
 @Setter
 @AllArgsConstructor
@@ -22,6 +22,7 @@ public class TicketComment {
     @GeneratedValue
     private Long id;
 
+    @Column(nullable = false, length = 2000)
     private String message;
 
     private LocalDateTime createdAt;
diff --git a/src/main/java/org/example/alfs/entities/User.java b/src/main/java/org/example/alfs/entities/User.java
index 29b59e1..43f85d3 100644
--- a/src/main/java/org/example/alfs/entities/User.java
+++ b/src/main/java/org/example/alfs/entities/User.java
@@ -2,7 +2,7 @@
 
 import jakarta.persistence.*;
 import lombok.*;
-import org.example.alfs.Role;
+import org.example.alfs.enums.Role;
 
 /*
 Represents a system user.
@@ -20,9 +20,10 @@ public class User {
     @Id
     private Long id;
 
+    @Column(nullable = false, unique = true, length = 100)
     private String username;
 
-    @Column(name = "password_hash", nullable = false, length = 255)
+    @Column(nullable = false, length = 255)
     private String passwordHash;
 
     @Enumerated(EnumType.STRING)
diff --git a/src/main/java/org/example/alfs/enums/AuditAction.java b/src/main/java/org/example/alfs/enums/AuditAction.java
new file mode 100644
index 0000000..36076c0
--- /dev/null
+++ b/src/main/java/org/example/alfs/enums/AuditAction.java
@@ -0,0 +1,8 @@
+package org.example.alfs.enums;
+
+public enum AuditAction {
+    CREATED,
+    UPDATED,
+    ASSIGNED,
+    COMMENTED
+}
\ No newline at end of file
diff --git a/src/main/java/org/example/alfs/Role.java b/src/main/java/org/example/alfs/enums/Role.java
similarity index 66%
rename from src/main/java/org/example/alfs/Role.java
rename to src/main/java/org/example/alfs/enums/Role.java
index 41dd236..3024fa1 100644
--- a/src/main/java/org/example/alfs/Role.java
+++ b/src/main/java/org/example/alfs/enums/Role.java
@@ -1,4 +1,4 @@
-package org.example.alfs;
+package org.example.alfs.enums;
 
 public enum Role {
     REPORTER,
diff --git a/src/main/java/org/example/alfs/enums/TicketStatus.java b/src/main/java/org/example/alfs/enums/TicketStatus.java
new file mode 100644
index 0000000..6442277
--- /dev/null
+++ b/src/main/java/org/example/alfs/enums/TicketStatus.java
@@ -0,0 +1,8 @@
+package org.example.alfs.enums;
+
+public enum TicketStatus {
+    OPEN,
+    IN_PROGRESS,
+    RESOLVED,
+    CLOSED
+}