Golang

Have you used Inbox and Outbox patterns?

Task: "Ping-pong with timeout" Write a function pingPong that: - Starts two goroutines: one generates "ping" messages, the other — "pong". - Goroutines should exchange messages through a shared channel strictly in turn. - The exchange continues for 3 seconds, after which the program should terminate (graceful shutdown). - Use context for cancellation via timeout. - Output each message on the screen along with the time (in milliseconds from start). Example of expected output: 0ms: ping

A simple live coding task (basic concurrency) Condition: Write a function fetchAll(urls []string) map[string]string that performs HTTP GET requests concurrently for each URL and returns a map where the key is the URL and the value is the response body (string). If the request fails (error, not 200), the value should be an empty string. Constraints: - Do not use external libraries (only standard). - Do not change the signature. - The program should not crash on panic in http.Get. Example input: ["[link]" "[link]" "[link]"]

package main import ( "fmt" ) func a(p *string) { s2 := "string2" *p = s2 } func main() { str1 := "string1" p := &str1 fmt.Println(*p) a(&p) fmt.Println(*p) }

Where are logs stored?

What to say to the interviewer (if asked) "I would use a worker pool with a fixed number of workers, a channel for tasks, and a sync.WaitGroup. The workers will execute requests, and timeout and cancellation will be controlled through the context. I will collect the results in a slice, protected by a mutex (or through a separate channel)."} Now it's your turn Write the code in this chat. I will review and give feedback. If you don't know where to start – ask for a hint. Good luck!

How do you ensure idempotency?

// all elements of the slice should be unique + consist of 1000 elements in total // the program should not hang due to time.sleep func main() { checkIncrement := map[int]int32{} var data []int for i := 0; i < 1000; i++ { go func() { data = append(data, i) if _, found := checkIncrement[i]; found { fmt.Println(i) panic("duplicated increment") } checkIncrement[i] = 1 }() } time.Sleep(2 * time.Second) fmt.Println(len(data)) }

What is a pointer and what happens if a function argument is a pointer?

Fill a slice with elements without a mutex so that it contains all 1000 elements.

Tell me about locks in Postgres.

What is the difference between DELETE and TRUNCATE?

Have you heard about distributed tracing?

How have you used Redis?

Tell us about your last project.