Triplebyte extensively screens candidates
The Triplebyte technical screen is completely background blind and has 2 steps. First, candidates complete a screening quiz. Second, candidates interview for 2 hours with a senior engineer. The content of the quiz and interview vary (we run several different versions of each). About 3% of candidates who apply pass both the quiz and interview and are introduced to companies.
Our quiz is an adaptive, multiple-choice test. We've assembled a large pool of potential questions, and the quiz asks each candidate different questions, based on where they have shown strength and weakness. By doing this we are able to get more accurate results in a shorter amount of time. The statistical model we use for our quiz (item response theory) is similar to what is behind the GRE and GMAT tests. Most of the quiz questions involve looking at blocks of code and answering questions about them (finding bugs and predicting behavior). Some questions test specific knowledge.
10% pass the quiz
Our interview is 2 hours long, and is conducted over screen share. We watch candidates work in their strongest language in their own environment. Our interviewers are all experienced engineers (the team includes past employees of Google, Facebook, Dropbox, Uber and Apple). We change the content of the interview over time (as we test new content). However, most interviews contain the following sections:
Here we give the candidate a spec, and ask them to write a program solving a problem. We look at their process, problem solving and ability to convert idea into code.
Here we gave the candidate a large existing program, and ask them to find and fix bugs. This better measures the abilities of experienced engineers to work with a large code base.
The exact content depends on the interview. But we ask a series of questions about CS fundamentals, back-end web, front-end web, mobile and low-level systems. The questions get harder as we go. Our aim is to measure how deep each candidate can go.
Here we give the candidate a spec for a large system (that would take weeks to complete), and have them talk about big-picture architectural concerns. We look for good discussion of tradeoffs.
For top performers on our quiz, we offer an expedited interview to move them through our process faster. These candidates succeed in onsites at a high rate, and the expedited process increases companies' probability of convincing them to join. The expedited interview covers the same topics as our regular interview, but each in a shorter time frame.
About 30% of candidates who do our interview pass and are introduced to companies. The quiz pass rate (10%) times the interview pass rate (30%) gives a total pass rate of 3%.
3% pass the quiz and interview
In some cases, Generalist-track candidates do so well on our adaptive test that they are offered an expedited interview with a senior engineer. We do this so that we can present them to companies more quickly; about 2% of the candidates that pass our quiz are given the expedited interview.
The expedited Ultrahigh interview covers the same sections as the normal 2-hour interview (back-end web, system design, algorithms / data structures, concurrency) and is with a senior engineer. However, we treat it as a knowledge-based interview, meaning that the candidates are not asked to code. Instead, they do a deep dive into the candidate's past experience, technical knowledge, and strengths / weaknesses as an engineer. We also dig into the candidate's coding examples, tendencies, and work style to better determine their coding abilities. All of this information is used to determine the scores you see on the candidate's profile.