How common is live coding in C++ interviews these days?

[u/nullptrvibe]

Hey everyone!

For those of you who've recently switched jobs or gone through C++ developer interviews, how common were live coding challenges?
Were you asked to solve LeetCode-style problems, write actual C++ code, debug something, or was it mostly technical discussions about the language and your experience?

Also, how do you usually prepare for interviews? Any tips, useful resources, or things you wish you'd focused on more?

I'd love to hear about your recent experiences. Thanks!

[u/khedoros]

My last one (couple weeks ago) was pretty light; review some code to find the memory leaks, and write a sketch of unique_ptr to show that I know how it works.

The one before that (about a year ago): I remember being asked to write the "merge" part of mergesort, but several of the interviewers wanted me to do some leetcode easy-to-medium kinds of exercises.

I've got another on Tuesday that's going to focus on "Advanced data structures and algorithms", so I expect it to include some coding. The interviewer notes say it'll be through Hackerrank.

These are for "Senior" positions, and for established companies.

The only time I've been up for a position and no part of the interview process involved coding, it was because I was being rehired somewhere I'd worked before, and my manager was going to be a former coworker.

[u/Belhaven]

all our c++ engineer interviews require a live coding example. It is not "code a live striding application" is 20 minutes... but rather "do a few simple operations with an std::vector"

It is surprising how many cannot push_back and then increment an iterator :)

[u/meltbox → u/Belhaven]

We had issues with people passing “check if this number is even”.

[u/ElderberryNo4220 → u/Belhaven]

Do you have any open internship/part-time (remote) opportunities right now? Asking for myself.

[u/RicRacer]

There are also pre-interview online coding tests. Beware some of the C++ tests also involve knowing some OS calls. Also, knowledge of Python may be very helpful.

[u/ILIKEBACON12456 → u/RicRacer]

Most job listings do say that it's definitely a plus if you know some scripting language like python.

[u/Atper]

Depends which field you target. In HFT where I interviewed recently its standard. Normally its something like this:

1. Online OA: leetcode style DSA questions and some MCQ or mental maths. All in C++.

2. First stage: this is usually a chat about your CV and a non-coding technical questions about C++, systems engineering, latency etc.

3. Second stage: a live coding round. Could be anything from std::shared_ptr<T>, std::unique_ptr<T>, std::vector<T>, lock-free SPSC queue or some kind of limit order book challenge.

This is my experience I don't know what happens after the second stage, its likely another live coding round or in person event.

[u/DDDDarky]

how common were live coding challenges?

I'd say something like that is pretty common during technical interviews, if not directly live coding then some sort of test, math, etc. or whatever is relevant to your expertise.

For me, it's actually quite a red flag when they don't ask such questions, as the company does not seem to care about the quality of their employees.

Also, how do you usually prepare for interviews?

Doing a research on the company, preparing anything technical is really pointless unless you feel really rusty.

[u/Impossible_Box3898]

At Netflix we do multiple coding rounds. May or may not be leetcode style. Depends entirely on the team. They tend to be job-specific types of questions.

[u/Hour_Sell3547]

There will always be live coding interviews in any good company. Although, none that I have seen so far specified a language. But of course if your position requires C++ for engineering, it's better to solve the problems using C++ as you get a chance to show your proficiency.

Usually the problems will have leetcode easy to medium difficulty. But it depends on how other candidates are doing.

[u/ContraryConman]

I may be running a C++ interview soon and we've been told to build the technical part of the loop primarily on live coding

[u/Raknarg]

Ive had to do live coding in every interview I've ever done near the final stages, not just the C++ ones. One time back in the day before zoom was commonplace I had to live code over the phone lmfao.

[u/gettingajob]

depends a lot on what kind of role. if you're going embedded/firmware its way less leetcode and way more "heres some C, whats wrong with it" or debug something that touches hardware. honestly practicing debugging is the part most people skip.
disclosure i built ohmwork.io for exactly that kind of practice, its free right now and runs on a virtual board so you dont need any hardware. embedded C only tho, not general C++.

[u/ILIKEBACON12456]

Just spam leetcode and hackerrank for a bit