全栈项目：论坛、抽奖、闪卡、家政、报表

前面写了不少行业系统，这次换几个日常能见到的：社区论坛、在线抽奖、学习闪卡、家政接单、数据报表导出。每个都是真实需求，英文提示词在前，中文说明帮你理清业务逻辑。

1. 简易论坛（帖子 + 评论 + 点赞）
Build a simple forum using Express + SQLite + JWT. Users can register/login. Authenticated users can create posts (title, content), edit/delete their own posts, add comments to any post, and like/unlike posts (one like per user per post). Posts list shows title, author, like count, comment count, timestamp. Support pagination (10 posts per page). Non-authenticated users can view posts and comments but cannot create or like. Use JWT in httpOnly cookie. Frontend: vanilla JS with fetch. Provide a search bar for posts by title. The challenge is managing likes (junction table) and comment relationships. No rich text, no file upload.

说人话：一个极简版论坛，用户可以发帖、回帖、点赞。难点是点赞的防重复和关联表的查询。不用富文本，纯文字就行。

2. 在线抽奖系统（转盘 + 概率 + 记录）
Create a lottery wheel system using Express + PostgreSQL + JWT for admin. Admin can configure prize list (name, probability, stock). Prize probabilities sum to 100. Users (registered) can spin the wheel once per day (limit based on last spin date). Spin result is determined server-side (random weighted selection) and recorded to database. Frontend: draw a simple wheel using Canvas, or just a button that calls API and shows result. Display user's past win records. Admin dashboard: view all spins, adjust prizes, reset user daily limits. Use transactions when deducting prize stock to prevent oversell. The challenge is weighted random selection, daily limit enforcement, and stock concurrency.

核心价值：抽奖系统的关键是概率算法和库存并发控制。按权重抽奖需要写个累加分布函数，扣库存要用事务。

3. 单词闪卡学习（间隔重复算法）
Build a flashcard learning system with spaced repetition using Next.js + Prisma + SQLite. Users register/login. Users can create decks of flashcards (question, answer). The system tests the user: show question, user reveals answer, then rates difficulty (easy/good/hard). Based on rating, schedule next review using a simple algorithm (e.g., easy: next day, good: 4 hours, hard: 1 hour). Store each card's next_review_date. A dashboard shows due cards for today. User can review cards in order of due date. Provide statistics: cards mastered, accuracy rate. Frontend: React components for flipping cards. Use JWT auth. The challenge is implementing the spaced repetition scheduling logic and filtering due cards.

适合场景：背单词软件的核心算法。间隔重复排期是难点，可以用一个简单的指数增长公式（下次间隔 = 当前间隔 × 系数）。

4. 家政服务预约（用户端 + 师傅端）
Implement a home service booking platform using NestJS + PostgreSQL + JWT. Roles: Customer, Worker (cleaner/plumber/electrician), Admin. Customers can browse services, book a worker on a selected date and time slot (1-hour slots, 9am-5pm). Workers see their assigned bookings, mark as started/completed. Admin approves new workers, sets hourly rate. Prevent double booking: a worker cannot have overlapping time slots. After service completion, customer can rate worker (1-5). Provide a simple calendar view for workers (list of bookings). Use transactions for booking. Frontend: simple React or vanilla with forms. The challenge is time slot availability, overlapping prevention, and role-based dashboards.

说人话：家政预约平台，顾客选时间下单，师傅接单并更新状态。核心是时间段不重叠的校验。

5. 销售报表导出（后端生成 Excel）
Develop a sales report export system using FastAPI + PostgreSQL + Celery. Data: pre-seed 10,000 sales records (date, product, category, quantity, revenue). Admin can generate a report by selecting date range and category filter. Because generating large Excel may take time, use Celery async task. After request, return task_id; frontend polls task status, then downloads generated file. Use openpyxl or xlsxwriter to create Excel with multiple sheets: summary pivot and detail rows. Provide a task history table in DB (task_id, status, file_path, created_at). Clean up old files after 24 hours (cron job). Frontend: simple upload/export interface. Docker-compose with FastAPI, Postgres, Redis (Celery broker), and a volume for files. The challenge is async task handling, Excel generation with large dataset, and file cleanup.

为什么选这个：后台导出功能经常遇到大文件超时问题。用 Celery 异步生成是标准做法，前端轮询下载。做完你对任务队列会有真实体感。

这五个补上了论坛社交、抽奖营销、学习工具、服务预约、数据报表。每个都带英文提示词和中文说明。做的时候注意：论坛的点赞表需要联合主键，抽奖的概率算法要测试边界，闪卡的排期逻辑先用变量写死后扩展，家政的时间段校验要处理跨天，报表导出要记得清理临时文件。全栈做到后面，你发现大部分时间不是在写新功能，而是在处理边界条件和异常情况。把这些想清楚，项目就稳了。