diff --git a/src/models/Reaction.ts b/src/models/Reaction.ts
index 4e48085..54cbe53 100644
--- a/src/models/Reaction.ts
+++ b/src/models/Reaction.ts
@@ -1,64 +1,49 @@
-import mongoose, { Document, PopulatedDoc, Schema } from 'mongoose';
-
-import { Model } from '../utils/constants';
-import { BaseModel, ID } from '../utils/types';
-import { PostDocument } from './Post';
-import { UserDocument } from './User';
-
-/**
- * TODO: (4.01)
- * - Read this enum.
- * - Delete this comment
- */
-export enum ReactionType {
-  FIRE = 'FIRE', // 🔥
-  HEART = 'HEART', // 💖
-  HUNDRED = 'HUNDRED', // 💯
-  LAUGH = 'LAUGH', // 😂
-  SAD = 'SAD' // 😢
-}
-
-/**
- * TODO: (4.02)
- * - Read this interface.
- * - Delete this comment once you've done so.
- */
-interface IReaction extends BaseModel {
-  /**
-   * Post that was "reacted" to.
-   */
-  post: PopulatedDoc<PostDocument>;
-
-  /**
-   * Type of the reaction, which corresponds to an emoji, as seen above.
-   *
-   * @default ReactionType.HEART
-   */
-  type: ReactionType;
-
-  /**
-   * User that made the reaction.
-   */
-  user: PopulatedDoc<UserDocument>;
-}
-
-export type ReactionDocument = Document<{}, {}, IReaction> & IReaction;
-
-const reactionSchema: Schema<ReactionDocument> = new Schema<ReactionDocument>(
-  {
-    /**
-     * TODO: (3.03)
-     * - Create the schema for the Reactions that we'll save in the database
-     * using the interface above as a reference.
-     * - Delete this comment and the example field.
-     * - Add comment(s) to explain your work.
-     */
-    exampleField: { required: true, type: String }
-  },
-  { timestamps: true }
-);
-
-const Reaction: mongoose.Model<ReactionDocument> =
-  mongoose.model<ReactionDocument>(Model.REACTION, reactionSchema);
-
-export default Reaction;
+import mongoose, { Document, PopulatedDoc, Schema } from 'mongoose';
+
+import { Model } from '../utils/constants';
+import { BaseModel, ID } from '../utils/types';
+import { PostDocument } from './Post';
+import { UserDocument } from './User';
+
+export enum ReactionType {
+  FIRE = 'FIRE', // 🔥
+  HEART = 'HEART', // 💖
+  HUNDRED = 'HUNDRED', // 💯
+  LAUGH = 'LAUGH', // 😂
+  SAD = 'SAD' // 😢
+}
+
+interface IReaction extends BaseModel {
+  /**
+   * Post that was "reacted" to.
+   */
+  post: PopulatedDoc<PostDocument>;
+
+  /**
+   * Type of the reaction, which corresponds to an emoji, as seen above.
+   *
+   * @default ReactionType.HEART
+   */
+  type: ReactionType;
+
+  /**
+   * User that made the reaction.
+   */
+  user: PopulatedDoc<UserDocument>;
+}
+
+export type ReactionDocument = Document<{}, {}, IReaction> & IReaction;
+
+const reactionSchema: Schema<ReactionDocument> = new Schema<ReactionDocument>(
+  {
+    post: { ref: Model.POST, required: true, type: ID },
+    type: { default: ReactionType.HEART, required: true, type: String },
+    user: { ref: Model.USER, required: true, type: ID }
+  },
+  { timestamps: true }
+);
+
+const Reaction: mongoose.Model<ReactionDocument> =
+  mongoose.model<ReactionDocument>(Model.REACTION, reactionSchema);
+
+export default Reaction;
diff --git a/src/routes/HelloWorldRoute.ts b/src/routes/HelloWorldRoute.ts
index f5f8e01..2c8f864 100644
--- a/src/routes/HelloWorldRoute.ts
+++ b/src/routes/HelloWorldRoute.ts
@@ -3,7 +3,7 @@ import { RouteMethod } from '../utils/constants';
 
 type HelloWorldResult = {
   message: string;
-  podmates: string[];    
+  podmates: string[];
 };
 
 // This is just a "dummy" endpoint that we can send a GET request to, to ensure