diff --git a/src/main/java/com/onixbyte/deltaforceguide/domain/entity/Firearm.java b/src/main/java/com/onixbyte/deltaforceguide/domain/entity/Firearm.java
index c38173f..65942d3 100644
--- a/src/main/java/com/onixbyte/deltaforceguide/domain/entity/Firearm.java
+++ b/src/main/java/com/onixbyte/deltaforceguide/domain/entity/Firearm.java
@@ -140,5 +140,88 @@ public class Firearm {
         this.modifications.remove(modification);
         modification.setFirearm(null);
     }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public static class Builder {
+
+        private Long id;
+        private String name;
+        private FirearmType type;
+        private String level;
+        private String review;
+        private String calibre;
+        private Integer fireRate;
+        private Integer armourDamage;
+        private Integer bodyDamage;
+        private List<Modification> modifications;
+
+        public Builder id(Long id) {
+            this.id = id;
+            return this;
+        }
+
+        public Builder name(String name) {
+            this.name = name;
+            return this;
+        }
+
+        public Builder type(FirearmType type) {
+            this.type = type;
+            return this;
+        }
+
+        public Builder level(String level) {
+            this.level = level;
+            return this;
+        }
+
+        public Builder review(String review) {
+            this.review = review;
+            return this;
+        }
+
+        public Builder calibre(String calibre) {
+            this.calibre = calibre;
+            return this;
+        }
+
+        public Builder fireRate(Integer fireRate) {
+            this.fireRate = fireRate;
+            return this;
+        }
+
+        public Builder armourDamage(Integer armourDamage) {
+            this.armourDamage = armourDamage;
+            return this;
+        }
+
+        public Builder bodyDamage(Integer bodyDamage) {
+            this.bodyDamage = bodyDamage;
+            return this;
+        }
+
+        public Builder modifications(List<Modification> modifications) {
+            this.modifications = modifications;
+            return this;
+        }
+
+        public Firearm build() {
+            Firearm firearm = new Firearm();
+            firearm.id = this.id;
+            firearm.name = this.name;
+            firearm.type = this.type;
+            firearm.level = this.level;
+            firearm.review = this.review;
+            firearm.calibre = this.calibre;
+            firearm.fireRate = this.fireRate;
+            firearm.armourDamage = this.armourDamage;
+            firearm.bodyDamage = this.bodyDamage;
+            firearm.modifications = this.modifications == null ? new ArrayList<>() : this.modifications;
+            return firearm;
+        }
+    }
 }
 
diff --git a/src/main/java/com/onixbyte/deltaforceguide/domain/entity/Modification.java b/src/main/java/com/onixbyte/deltaforceguide/domain/entity/Modification.java
index 6f29bd5..6ed3ec6 100644
--- a/src/main/java/com/onixbyte/deltaforceguide/domain/entity/Modification.java
+++ b/src/main/java/com/onixbyte/deltaforceguide/domain/entity/Modification.java
@@ -116,5 +116,74 @@ public class Modification {
     public void setVideoUrl(String videoUrl) {
         this.videoUrl = videoUrl;
     }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public static class Builder {
+
+        private Long id;
+        private Firearm firearm;
+        private String name;
+        private String code;
+        private List<String> tags;
+        private String note;
+        private String author;
+        private String videoUrl;
+
+        public Builder id(Long id) {
+            this.id = id;
+            return this;
+        }
+
+        public Builder firearm(Firearm firearm) {
+            this.firearm = firearm;
+            return this;
+        }
+
+        public Builder name(String name) {
+            this.name = name;
+            return this;
+        }
+
+        public Builder code(String code) {
+            this.code = code;
+            return this;
+        }
+
+        public Builder tags(List<String> tags) {
+            this.tags = tags;
+            return this;
+        }
+
+        public Builder note(String note) {
+            this.note = note;
+            return this;
+        }
+
+        public Builder author(String author) {
+            this.author = author;
+            return this;
+        }
+
+        public Builder videoUrl(String videoUrl) {
+            this.videoUrl = videoUrl;
+            return this;
+        }
+
+        public Modification build() {
+            Modification modification = new Modification();
+            modification.id = this.id;
+            modification.firearm = this.firearm;
+            modification.name = this.name;
+            modification.code = this.code;
+            modification.tags = this.tags == null ? new ArrayList<>() : this.tags;
+            modification.note = this.note;
+            modification.author = this.author;
+            modification.videoUrl = this.videoUrl;
+            return modification;
+        }
+    }
 }
 
diff --git a/src/main/java/com/onixbyte/deltaforceguide/domain/entity/User.java b/src/main/java/com/onixbyte/deltaforceguide/domain/entity/User.java
index 31cf527..67142df 100644
--- a/src/main/java/com/onixbyte/deltaforceguide/domain/entity/User.java
+++ b/src/main/java/com/onixbyte/deltaforceguide/domain/entity/User.java
@@ -70,4 +70,45 @@ public class User {
         this.credentials.remove(credential);
         credential.setUser(null);
     }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public static class Builder {
+
+        private Long id;
+        private String username;
+        private String email;
+        private List<UserCredential> credentials;
+
+        public Builder id(Long id) {
+            this.id = id;
+            return this;
+        }
+
+        public Builder username(String username) {
+            this.username = username;
+            return this;
+        }
+
+        public Builder email(String email) {
+            this.email = email;
+            return this;
+        }
+
+        public Builder credentials(List<UserCredential> credentials) {
+            this.credentials = credentials;
+            return this;
+        }
+
+        public User build() {
+            User user = new User();
+            user.id = this.id;
+            user.username = this.username;
+            user.email = this.email;
+            user.credentials = this.credentials == null ? new ArrayList<>() : this.credentials;
+            return user;
+        }
+    }
 }
diff --git a/src/main/java/com/onixbyte/deltaforceguide/domain/entity/UserCredential.java b/src/main/java/com/onixbyte/deltaforceguide/domain/entity/UserCredential.java
index 44e409e..b8a09a6 100644
--- a/src/main/java/com/onixbyte/deltaforceguide/domain/entity/UserCredential.java
+++ b/src/main/java/com/onixbyte/deltaforceguide/domain/entity/UserCredential.java
@@ -80,4 +80,59 @@ public class UserCredential {
 	public void setCredential(String credential) {
 		this.credential = credential;
 	}
+
+	public static Builder builder() {
+		return new Builder();
+	}
+
+	public static class Builder {
+
+		private UserCredentialId id;
+		private User user;
+		private Long userId;
+		private String provider;
+		private String credential;
+
+		public Builder id(UserCredentialId id) {
+			this.id = id;
+			return this;
+		}
+
+		public Builder user(User user) {
+			this.user = user;
+			return this;
+		}
+
+		public Builder userId(Long userId) {
+			this.userId = userId;
+			return this;
+		}
+
+		public Builder provider(String provider) {
+			this.provider = provider;
+			return this;
+		}
+
+		public Builder credential(String credential) {
+			this.credential = credential;
+			return this;
+		}
+
+		public UserCredential build() {
+			UserCredential userCredential = new UserCredential();
+			userCredential.id = this.id == null ? new UserCredentialId() : this.id;
+			userCredential.user = this.user;
+			if (this.user != null) {
+				userCredential.id.setUserId(this.user.getId());
+			}
+			if (this.userId != null) {
+				userCredential.id.setUserId(this.userId);
+			}
+			if (this.provider != null) {
+				userCredential.id.setProvider(this.provider);
+			}
+			userCredential.credential = this.credential;
+			return userCredential;
+		}
+	}
 }
diff --git a/src/main/java/com/onixbyte/deltaforceguide/domain/entity/UserCredentialId.java b/src/main/java/com/onixbyte/deltaforceguide/domain/entity/UserCredentialId.java
index ac1a98c..57a819e 100644
--- a/src/main/java/com/onixbyte/deltaforceguide/domain/entity/UserCredentialId.java
+++ b/src/main/java/com/onixbyte/deltaforceguide/domain/entity/UserCredentialId.java
@@ -44,6 +44,33 @@ public class UserCredentialId implements Serializable {
     public int hashCode() {
         return Objects.hash(userId, provider);
     }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public static class Builder {
+
+        private Long userId;
+        private String provider;
+
+        public Builder userId(Long userId) {
+            this.userId = userId;
+            return this;
+        }
+
+        public Builder provider(String provider) {
+            this.provider = provider;
+            return this;
+        }
+
+        public UserCredentialId build() {
+            UserCredentialId id = new UserCredentialId();
+            id.userId = this.userId;
+            id.provider = this.provider;
+            return id;
+        }
+    }
 }