diff --git a/assets/database.mmd b/assets/database.mmd
new file mode 100644
index 0000000..79d5b76
--- /dev/null
+++ b/assets/database.mmd
@@ -0,0 +1,117 @@
+---
+config:
+  theme: redux-color
+---
+erDiagram
+    PENDING_USER {
+        int id PK
+        string email UK
+        string password_hash
+        string handle_candidate
+        datetime requested_at
+        datetime expires_at
+    }
+    EMAIL_VERIFICATION_TOKEN {
+        int id PK
+        int pending_user_id FK
+        string token UK
+        datetime sent_at
+        datetime expires_at
+        datetime consumed_at
+    }
+    USER {
+        int id PK
+        string email UK
+        string handle UK
+        string password_hash
+        datetime email_confirmed_at
+        datetime created_at
+    }
+    PENDING_USER ||--o{ EMAIL_VERIFICATION_TOKEN : ""
+    PROBLEM {
+        int id PK
+        string code
+        string title
+        datetime created_at
+    }
+    STATEMENT {
+        int id PK
+        int problem_id FK
+        string language
+        text content_md
+    }
+    SOLUTION {
+        int id PK
+        int problem_id FK
+        enum role
+        string path
+    }
+    TEST_GROUP {
+        int id PK
+        int problem_id FK
+        string name
+        int ordinal
+        int points
+    }
+    TEST {
+        int id PK
+        int group_id FK
+        string in_file_path
+        string ans_file_path
+    }
+    RESOURCE_FILE {
+        int id PK
+        int problem_id FK
+        enum kind "checker/validator/generator"
+        string path
+    }
+    TAG {
+        int id PK
+        int problem_id FK
+        string name
+    }
+    PROBLEM_AUTHOR {
+        int problem_id FK
+        int user_id FK
+    }
+    USER ||--o{ PROBLEM_AUTHOR : ""
+    PROBLEM ||--o{ PROBLEM_AUTHOR : ""
+    PROBLEM ||--o{ STATEMENT : ""
+    PROBLEM ||--o{ SOLUTION  : ""
+    PROBLEM ||--o{ TEST_GROUP : ""
+    TEST_GROUP ||--o{ TEST : ""
+    PROBLEM ||--o{ RESOURCE_FILE : ""
+    PROBLEM ||--o{ TAG : ""
+    CONTEST {
+        int id PK
+        string code
+        string title
+        datetime start_time
+        datetime end_time
+    }
+    CONTEST_PROBLEM {
+        int contest_id FK
+        int problem_id FK
+        char alias "A/B/C…"
+        int ordinal
+        int points_override
+    }
+    CONTEST_AUTHOR {
+        int contest_id FK
+        int user_id FK
+    }
+    USER    ||--o{ CONTEST_AUTHOR  : ""
+    CONTEST ||--o{ CONTEST_AUTHOR  : ""
+    CONTEST ||--o{ CONTEST_PROBLEM : ""
+    PROBLEM ||--o{ CONTEST_PROBLEM : ""
+    PACKAGE {
+        int id PK
+        enum type "problem/contest"
+        int problem_id FK
+        int contest_id FK
+        string version
+        datetime built_at
+        string storage_path
+    }
+    PROBLEM ||--o{ PACKAGE : ""
+    CONTEST ||--o{ PACKAGE : ""
diff --git a/assets/database.png b/assets/database.png
new file mode 100644
index 0000000..efa1420
Binary files /dev/null and b/assets/database.png differ