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C++ vs Go for Backend Services: Memory, Concurrency and Trade-offs

ByteDanceSoftware Engineer · Technical Screen
MediumSoftware EngineerTechnical ScreenSoftware Engineering Fundamentals

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From a TikTok backend intern interview: compare C++ and Go across memory management, concurrency, error handling, language features and tooling, and explain when each language is the better choice for a service. It tests practical understanding of runtime trade-offs rather than syntax trivia.

Compare C++ and Go. Explain the main differences between the two languages and when you would choose each one, for example for the backend services this team builds.

Clarifying Questions

  • Should the comparison focus on writing backend services, or on systems programming in general?
  • Which C++ standard should be assumed, since modern C++ (smart pointers, move semantics, coroutines) changes several answers?

Hints

Hint 1

Organize by runtime model: Compare how each language manages memory, runs concurrent work, reports errors and builds and ships its binaries, then ask what each difference costs or buys a backend service.

Follow-up questions

  • How does the Go scheduler run goroutines on OS threads, and what happens when a goroutine makes a blocking system call?
  • What do `std::unique_ptr` and `std::shared_ptr` each cost, and when does `shared_ptr` cause problems?
  • How does Go's escape analysis decide whether a value lives on the stack or the heap, and why does that matter for garbage collection?
  • Go has no exceptions. How do you propagate and wrap errors, and when is `panic` appropriate?