Tech Support / L1-L3

What are channels in Go? The difference between buffered and unbuffered channels.

What is DNS and how does it work? What are the main nodes in this system?

/** * Repeating characters * * Write a function that takes a string as input and returns * for each unique character the maximum number of its consecutive repetitions. * * Input: qqffbbaaaffc * Output: a:4 b:1 f:2 c:1 * * Input: bbbbbb * Output: b:6 * * Input: abc * Output: a:1 b:1 c:1 * * Input: aabbcc * Output: a:2 b:2 c:2 * * Input: aaabbbccc * Output: a:3 b:3 c:3 * * Input: a * Output: a:1 * * Input: "" * Output: */

Why is atomic called so and how does it work?

What is the difference between arrays and slices in Go? How does the capacity of a slice change?

What are goroutines in Go? How do they differ from OS threads?

Why do not all use Serializable? How does the isolation level affect performance?

TCP and UDP — what is the main difference between these network protocols?

Select operator in Go — features of working with multiple channels

What is O-notation (Big O notation)? Tell the main points.

Is it possible to control the number of OS threads for goroutines?

Containerization and virtualization are the main difference between these technologies

What is deadlock and what is race condition?

How are interfaces structured in Go?

What is a pointer and how much does it weigh?

What is SQL injection and how to prevent it?

How to use embedding to simulate inheritance in Go?

What are transactions in databases? What is the meaning and main difference of transaction isolation levels?

How to create custom types based on structures in Go?

Why are indexes not created on all columns and all combinations in a row?