Tell us about your commercial experience working with PostgreSQL and Redis. Since what year have you been working, what tasks have you solved? Provide interesting cases.

I have been working with PostgreSQL since 2016 and with Redis since 2018. In PostgreSQL, I have solved tasks related to optimizing complex queries, designing database schemas, and implementing transactional logic. For example, in one project, I optimized queries using indexes and table partitioning, which reduced response time from several seconds to hundreds of milliseconds.

With Redis, I worked as a cache and message broker. In one case, I implemented a rate limiting system using Redis, utilizing atomic operations INCR and EXPIRE to limit the number of requests from a user within a certain period.

Example of using Redis for rate limiting in Go:

import (
    "github.com/go-redis/redis/v8"
    "context"
    "time"
)

func rateLimit(ctx context.Context, rdb *redis.Client, key string, limit int, window time.Duration) (bool, error) {
    count, err := rdb.Incr(ctx, key).Result()
    if err != nil {
        return false, err
    }
    if count == 1 {
        rdb.Expire(ctx, key, window)
    }
    return count <= int64(limit), nil
}

This experience allows me to effectively utilize the capabilities of both technologies to solve a wide range of tasks.