Have you worked with caching? If yes, what kind?

Yes, in Go projects I have used caching to improve performance and reduce database load. Mainly worked with:

• Built-in in-memory cache using map and sync.RWMutex for thread safety.
• Redis as an external cache for distributed systems, using the go-redis library.

Example of a simple in-memory cache:

package main

import (
    "sync"
    "time"
)

type Cache struct {
    mu    sync.RWMutex
    store map[string]string
}

func NewCache() *Cache {
    return &Cache{store: make(map[string]string)}
}

func (c *Cache) Get(key string) (string, bool) {
    c.mu.RLock()
    defer c.mu.RUnlock()
    val, ok := c.store[key]
    return val, ok
}

func (c *Cache) Set(key, value string) {
    c.mu.Lock()
    defer c.mu.Unlock()
    c.store[key] = value
}

func main() {
    cache := NewCache()
    cache.Set("user_1", "John Doe")
    if val, ok := cache.Get("user_1"); ok {
        println(val) // John Doe
    }
    // You can add logic for time-based clearing, etc.
}

This approach helps reduce the number of requests to slow data sources and speeds up service response.