Async Rust with Tokio

Most Grok Insider services use Tokio as the async runtime: many sockets, one process, no thread-per-request.

Minimal server shape

#[tokio::main]
async fn main() {
    // bind, accept, spawn per connection
}

Mental model

• .await yields while I/O is pending.
• tokio::spawn runs independent tasks on the runtime.
• Prefer structured concurrency: cancel children when the parent ends.

Tips for APIs

• Share state with Arc.
• Use a connection pool for Redis/DB.
• Add timeouts on outbound calls.

Async is not “free threads” — it is cooperative scheduling. Keep CPU-heavy work off the async executor.