diff --git a/backend/src/db/migrate.js b/backend/src/db/migrate.js
new file mode 100644
index 0000000..b5af4d4
--- /dev/null
+++ b/backend/src/db/migrate.js
@@ -0,0 +1,126 @@
+/**
+ * Database Migration Script
+ * Executes SQL migration files in order
+ */
+
+import { readFileSync, readdirSync } from 'fs';
+import { join } from 'path';
+import pg from 'pg';
+
+const { Pool } = pg;
+
+// Database configuration
+const dbConfig = {
+  host: process.env.DB_HOST || 'localhost',
+  port: parseInt(process.env.DB_PORT || '5433', 10),
+  database: process.env.DB_NAME || 'clinic_tests',
+  user: process.env.DB_USER || 'developer',
+  password: process.env.DB_PASSWORD || 'dev_password',
+};
+
+const MIGRATIONS_DIR = join(process.cwd(), 'src', 'db', 'migrations');
+
+/**
+ * Get list of migration files sorted by name
+ */
+function getMigrationFiles() {
+  const files = readdirSync(MIGRATIONS_DIR)
+    .filter((file) => file.endsWith('.sql'))
+    .sort();
+
+  return files;
+}
+
+/**
+ * Create migrations tracking table if not exists
+ */
+async function ensureMigrationsTable(pool) {
+  await pool.query(`
+    CREATE TABLE IF NOT EXISTS migrations (
+      id SERIAL PRIMARY KEY,
+      name VARCHAR(255) NOT NULL UNIQUE,
+      executed_at TIMESTAMP DEFAULT NOW()
+    )
+  `);
+}
+
+/**
+ * Get list of already executed migrations
+ */
+async function getExecutedMigrations(pool) {
+  const result = await pool.query('SELECT name FROM migrations ORDER BY name');
+  return result.rows.map((row) => row.name);
+}
+
+/**
+ * Execute a single migration file
+ */
+async function executeMigration(pool, filename) {
+  const filePath = join(MIGRATIONS_DIR, filename);
+  const sql = readFileSync(filePath, 'utf-8');
+
+  console.log(`Executing migration: ${filename}`);
+  
+  await pool.query('BEGIN');
+  try {
+    await pool.query(sql);
+    await pool.query(
+      'INSERT INTO migrations (name) VALUES ($1)',
+      [filename]
+    );
+    await pool.query('COMMIT');
+    console.log(`✓ Migration ${filename} completed successfully`);
+  } catch (error) {
+    await pool.query('ROLLBACK');
+    console.error(`✗ Migration ${filename} failed:`, error.message);
+    throw error;
+  }
+}
+
+/**
+ * Main migration function
+ */
+async function migrate() {
+  const pool = new Pool(dbConfig);
+
+  try {
+    console.log('Connecting to database...');
+    await pool.connect();
+    console.log('Connected to database\n');
+
+    // Ensure migrations table exists
+    await ensureMigrationsTable(pool);
+
+    // Get migration files and already executed migrations
+    const migrationFiles = getMigrationFiles();
+    const executedMigrations = await getExecutedMigrations(pool);
+
+    console.log(`Found ${migrationFiles.length} migration file(s)`);
+    console.log(`Already executed: ${executedMigrations.length} migration(s)\n`);
+
+    // Execute pending migrations
+    const pendingMigrations = migrationFiles.filter(
+      (file) => !executedMigrations.includes(file)
+    );
+
+    if (pendingMigrations.length === 0) {
+      console.log('All migrations already executed.');
+    } else {
+      console.log(`Pending migrations: ${pendingMigrations.length}\n`);
+      
+      for (const filename of pendingMigrations) {
+        await executeMigration(pool, filename);
+      }
+
+      console.log(`\n✓ Successfully executed ${pendingMigrations.length} migration(s)`);
+    }
+  } catch (error) {
+    console.error('\n✗ Migration failed:', error.message);
+    process.exit(1);
+  } finally {
+    await pool.end();
+  }
+}
+
+// Run migrations if this script is executed directly
+migrate();
diff --git a/backend/src/index.js b/backend/src/index.js
new file mode 100644
index 0000000..1d71a9e
--- /dev/null
+++ b/backend/src/index.js
@@ -0,0 +1,52 @@
+import express from 'express';
+import cors from 'cors';
+import cookieParser from 'cookie-parser';
+import dotenv from 'dotenv';
+
+import authRoutes from './routes/auth.js';
+
+dotenv.config();
+
+const app = express();
+const PORT = process.env.PORT || 3001;
+
+// Middleware
+app.use(cors({
+  origin: process.env.NODE_ENV === 'production'
+    ? process.env.FRONTEND_URL
+    : ['http://localhost:5173', 'http://localhost:3000'],
+  credentials: true,
+}));
+app.use(express.json());
+app.use(cookieParser());
+
+// Mount auth routes
+app.use('/api/auth', authRoutes);
+
+// Health check route
+app.get('/api/health', (req, res) => {
+  res.json({
+    status: 'ok',
+    timestamp: new Date().toISOString(),
+    message: 'Server is running',
+  });
+});
+
+// Error handling middleware
+app.use((err, req, res, _next) => {
+  console.error('Error:', err);
+  res.status(err.status || 500).json({
+    error: err.message || 'Internal Server Error',
+  });
+});
+
+// 404 handler
+app.use((req, res) => {
+  res.status(404).json({ error: 'Not found' });
+});
+
+// Start server
+app.listen(PORT, () => {
+  console.log(`Server is running on port ${PORT}`);
+  console.log(`Environment: ${process.env.NODE_ENV || 'development'}`);
+});
diff --git a/docs/revision_task/TESTING_JOURNAL.md b/docs/revision_task/TESTING_JOURNAL.md
index 9b56c34..34a2c95 100644
--- a/docs/revision_task/TESTING_JOURNAL.md
+++ b/docs/revision_task/TESTING_JOURNAL.md
@@ -22,10 +22,10 @@
 
 | № | Что проверено | Статус | Дата |
 |---|----------------|--------|------|
-| A1 | В проекте есть миграция базы: связь версий «родитель» (`parent_id`) и правило «только одна активная версия на тест» | [ ] | |
-| A2 | Линтер (`npm run lint`) без **новых** ошибок в добавленных файлах; в проекте есть старые замечания линтера | частично | 2026-04-24 |
+| A1 | В проекте есть миграция базы: связь версий «родитель» (`parent_id`) и правило «только одна активная версия на тест» | [x] `002_…sql` | 2026-04-24 |
+| A2 | Линтер (`npm run lint`): **0 errors**; остаются **warnings** `no-console` в существующих файлах | готово (errors) | 2026-04-24 |
 | A3 | Автотесты: функция «есть ли уже хотя бы одна попытка по этому тесту» (`npm test`) | [x] готово | 2026-04-23 |
-| A4 | Запрос «здоров ли сервер» по адресу `/api/health` при запущенном backend | [ ] | |
+| A4 | Запрос «здоров ли сервер» по адресу `/api/health` при запущенном backend | [x] `{"status":"ok"}` | 2026-04-24 |
 
 **Техническая заметка:** реализация `hasAnyAttemptForTest` в `backend/src/services/testChainService.js`, тесты в `testChainService.test.js`.