Concurrent Web Scraper: Develop a highly efficient concurrent web scraper using Rust's async capabilities, leveraging tokio for managing network requests and handling data concurrently. This tool can scrape multiple websites simultaneously with robust error handling and backpressure mechanisms.

Async Task Scheduler: Create an async task scheduling application in Rust, allowing users to schedule, manage, and execute tasks asynchronously. Utilize tokio::select! for task cancellations and tokio::sync::oneshot for communication between scheduled tasks and the central management system.

Real-time Chat Application: Build a real-time chat application with Rust using websockets, incorporating tokio for async message handling. Implement channels (tokio::sync::mpsc and tokio::sync::broadcast) for efficient message distribution to multiple users.

Async File Processing System: Develop a system for processing large volumes of files asynchronously. Use tokio for non-blocking I/O operations and implement queues with tokio::sync::mpsc to parallelize file processing tasks.

High-performance HTTP Server: Design a high-performance HTTP server using Rust and hyper, capable of handling numerous concurrent requests efficiently. Leverage tokio::spawn to manage connections and ensure minimal latency with robust backpressure controls.

Rust-based Microservice Framework: Create a framework for building microservices in Rust with complete async support, providing libraries for common operations like HTTP routing, database interaction with sqlx, and service discovery.

Async Data Pipeline: Construct an async data processing pipeline that ingests data, processes it in parallel, and outputs it to storage like an async database using tokio-postgres. Implement bounded channels to handle flow control and back pressure.

Smart IoT Device Manager: Develop a Rust-based IoT device management system, coordinating multiple devices asynchronously using tokio. Implement error handling strategies to maintain device connections and ensure reliable operations.

Distributed Key-Value Store: Design a distributed key-value store using Rust's concurrency model, with async networking for replication and tokio::sync::RwLock for handling concurrent read-write operations.

Async API Gateway: Build an async API gateway in Rust for handling large scale API requests, implementing load balancing, and asynchronous request forwarding with serde for payload management and reqwest for external API calls.