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12## Project Structure
13
14- `/backend` - Server-side code with Hono API and SQLite database
15- `/frontend` - Client-side HTML, CSS, and JavaScript
16- `/shared` - Shared types and utilities
20- TypeScript
21- Hono (API framework)
22- SQLite (database)
23- TailwindCSS (styling)

46    "slug": "codegen",
47    "link": "/blog/codegen",
48    "description": "Like Claude Artifacts, but with a backend and database",
49    "pubDate": "Thu, 22 Aug 2024 00:00:00 GMT",
50    "author": "JP Posma",

1---
2title: "Post-mortem: A Backward Incompatible Database Migration"
3description: Val runs failed due to a database migration that was not backward compatible
4pubDate: 2025-04-02T00:00:00.000Z
5author: Sophie Houser
6---
7
8Today at 10:11am we experienced a 12-minute outage, which caused HTTP vals to return 503 errors and other types of vals to fail. In the end, the root cause was a deployment timing issue where database migrations were deployed successfully, but our application code deployment hung for several minutes. The new database migrations were incompatible with the old application code and crashed the process. 
9
10We aim to make all database migrations maintain backward compatibility, but in this case, we only discovered through the delayed deployment feedback that the new migrations were not compatible with previous versions.
11
12## Timeline
27## Next Steps
28
29Reliability is important to us and we’ve taken steps to make sure this doesn’t happen again. We’ve added a test to ensure database migrations are backward compatible, which we’ll run before we deploy any new code that includes database migrations.

1import { Hono } from "https://esm.sh/hono@3.11.7";
2import { OpenAI } from "https://esm.town/v/std/openai";
3import { getAllTools, getToolsByCategory, getToolById, searchTools } from "../database/queries";
4import { AITool, SearchRequest, ToolCategory } from "../../shared/types";
5

7
8// Create tables for the AI tools directory
9export async function setupDatabase() {
10  // Create tools table
11  await sqlite.execute(`
31  `);
32
33  // Check if we need to seed the database
34  const count = await sqlite.execute(`SELECT COUNT(*) as count FROM ${TOOLS_TABLE}`);
35  if (count.rows[0].count === 0) {
36    await seedDatabase();
37  }
38}
39
40// Seed the database with initial AI tools
41async function seedDatabase() {
42  // Sample tools data
43  const tools = [

17```
18├── backend/
19│   ├── database/
20│   │   ├── migrations.ts    # Database schema setup
21│   │   └── queries.ts       # Database query functions
22│   ├── routes/
23│   │   └── api.ts           # API routes for search and recommendations
47- Backend: Hono API framework
48- AI: OpenAI for query understanding and tool recommendations
49- Database: SQLite for tool information storage

4import { useAuth } from "../../hooks/useAuth";
5import { useExamService } from "../../hooks/useExamService";
6import { Exam, Attempt } from "../../../shared/database/schema";
7
8const AdminDashboard: React.FC = () => {

4import { useAuth } from "../../hooks/useAuth";
5import { useExamService } from "../../hooks/useExamService";
6import { Attempt, Exam, Question, Answer } from "../../../shared/database/schema";
7
8interface QuestionWithAnswer extends Question {

4import { useAuth } from "../../hooks/useAuth";
5import { useExamService } from "../../hooks/useExamService";
6import { Exam, Question, Attempt } from "../../../shared/database/schema";
7
8const TakeExam: React.FC = () => {
128    }));
129    
130    // Save answer to database
131    if (attempt) {
132      const currentQuestion = questions[currentQuestionIndex];

4import { useAuth } from "../../hooks/useAuth";
5import { useExamService } from "../../hooks/useExamService";
6import { Exam, Attempt } from "../../../shared/database/schema";
7
8const StudentDashboard: React.FC = () => {