diff --git a/packages/backend/src/models/base.ts b/packages/backend/src/models/base.ts
index 95c40746..6bfdc60d 100644
--- a/packages/backend/src/models/base.ts
+++ b/packages/backend/src/models/base.ts
@@ -2,9 +2,15 @@ import { AjvValidator, Model, snakeCaseMappers } from 'objection';
 import type { QueryContext, ModelOptions, ColumnNameMappers } from 'objection';
 import addFormats from 'ajv-formats';
 
+import ExtendedQueryBuilder from './query-builder';
+
 class Base extends Model {
   createdAt!: string;
   updatedAt!: string;
+  deletedAt: string;
+
+  QueryBuilderType!: ExtendedQueryBuilder<this>;
+  static QueryBuilder = ExtendedQueryBuilder;
 
   static get columnNameMappers(): ColumnNameMappers {
     return snakeCaseMappers();
@@ -30,10 +36,10 @@ class Base extends Model {
     this.updatedAt = new Date().toISOString();
   }
 
-  async $beforeUpdate(opt: ModelOptions, queryContext: QueryContext): Promise<void> {
+  async $beforeUpdate(opts: ModelOptions, queryContext: QueryContext): Promise<void> {
     this.updatedAt = new Date().toISOString();
 
-    await super.$beforeUpdate(opt, queryContext);
+    await super.$beforeUpdate(opts, queryContext);
   }
 }
 
diff --git a/packages/backend/src/models/query-builder.ts b/packages/backend/src/models/query-builder.ts
new file mode 100644
index 00000000..9e89f4bf
--- /dev/null
+++ b/packages/backend/src/models/query-builder.ts
@@ -0,0 +1,43 @@
+import { Model, Page, PartialModelObject, ForClassMethod, AnyQueryBuilder } from "objection";
+
+const DELETED_COLUMN_NAME = 'deleted_at';
+
+const buildQueryBuidlerForClass = (): ForClassMethod => {
+  return (modelClass) => {
+    const qb: AnyQueryBuilder = Model.QueryBuilder.forClass.call(ExtendedQueryBuilder, modelClass);
+    qb.onBuild((builder) => {
+      if (!builder.context().withSoftDeleted) {
+        builder.whereNull(`${qb.modelClass().tableName}.${DELETED_COLUMN_NAME}`);
+      }
+    });
+    return qb;
+  };
+};
+
+class ExtendedQueryBuilder<M extends Model, R = M[]> extends Model.QueryBuilder<M, R> {
+  ArrayQueryBuilderType!: ExtendedQueryBuilder<M, M[]>;
+  SingleQueryBuilderType!: ExtendedQueryBuilder<M, M>;
+  MaybeSingleQueryBuilderType!: ExtendedQueryBuilder<M, M | undefined>;
+  NumberQueryBuilderType!: ExtendedQueryBuilder<M, number>;
+  PageQueryBuilderType!: ExtendedQueryBuilder<M, Page<M>>;
+
+  static forClass: ForClassMethod = buildQueryBuidlerForClass();
+
+  delete() {
+    return this.patch({
+      [DELETED_COLUMN_NAME]: (new Date()).toISOString(),
+    } as unknown as PartialModelObject<M>);
+  }
+
+  hardDelete() {
+    return super.delete();
+  }
+
+  restore() {
+    return this.patch({
+      [DELETED_COLUMN_NAME]: null,
+    } as unknown as PartialModelObject<M>);
+  }
+}
+
+export default ExtendedQueryBuilder;