The goal of any interview process is to derive meaningful signal about a candidate’s ability to do the job. In my career I’ve done a good amount of interviewing as the interviewer, and have spent a lot of time working on improving questions, the execution of a given interview, and all the processes around assessing software engineers. What I’ve learned over time is that a good interview process is explicit about what signals it is attempting to measure, uses standardized questions and paired interviews to reduce bias, and is clear with the candidate what to expect and what signals the process is looking for.
Signals
Before you can figure out what questions you’re going to ask, you need to know what kind of answers help you make a decision.
Signals are the intent behind all of your interview questions. Coming up with them is the most critical part of defining your interview process, and allows you to work backwards to solid questions. Signals should be derived from the actual work you are doing, and what you expect a candidate to be able to perform. For example, signals I’ve used in the past:
- Ability to debug a program.
- Ability to extend a working program with a new feature.
- Ability to perform a code review.
- Ability to reason about correctness or performance tradeoffs in a systems architecture.
From there you can further refine each signal (e.g. “what do we value in a code review?”) and then design questions to clearly reveal that signal.
Be honest about what your process is actually testing. Does your team write hash map implementations from scratch? If not, do not ask candidates to do it. A rigorous process is one that is rigorous about measuring the right things.
Candidate Experience
The goal of a good interview process is to help the candidate succeed and give them every opportunity to demonstrate the signal you care about. That starts with empathy: interviewing is stressful, and the process should be designed to reduce unnecessary anxiety rather than add to it.
Be transparent with candidates about what you are looking for. Before the interview, tell them what signals matter and what format the interview will take. This is not giving away the answers, it is leveling the playing field. A candidate who knows you care about debugging ability can prepare meaningfully, and you get a much better read on their actual skill rather than their ability to guess what you want.
During the interview itself, create space for the candidate to think out loud and ask clarifying questions. As I like to tell candidates: “We don’t solve problems by getting 3 people in a room and making 1 person whiteboard in silence, so lets talk”. The best interviews feel like a collaborative working session, not a test. If a candidate is stuck, a well placed hint tells you just as much about how they incorporate feedback as watching them struggle in silence.
Bias
Everyone carries unconscious bias into an interview. The goal is not to pretend it does not exist, but to design a process that actively reduces its impact.
Paired interviews are one of the most effective tools for this. One person drives the interview while the other observes. This gives you two independent perspectives on the same interaction, and allows for meaningful calibration during the hiring huddle. If two interviewers saw the same moment differently, that is a conversation worth having.
Equally important: interviewers should not discuss the interview until after they have each written down their feedback independently, and ideally not until the hiring huddle itself. If one interviewer shares their opinion beforehand, it anchors everyone else. Independent written feedback preserves the value of having multiple perspectives in the first place.