The Interview Process That Finds Great Engineers

I've been on both sides of thousands of engineering interviews. As a candidate, I've whiteboarded binary tree inversions that had nothing to do with the job I was applying for. As a hiring manager, I've watched brilliant engineers fail algorithm puzzles while mediocre ones sailed through because they'd spent three months grinding LeetCode. The correlation between our interview scores and actual on-the-job performance was, to put it diplomatically, weak.

Two years ago, I scrapped our entire engineering interview process and rebuilt it from scratch. The results have been transformative — not just in the quality of engineers we hire, but in our offer acceptance rate and the diversity of our team. Here's what we built and why it works.

The Problem with Traditional Technical Interviews

The standard technical interview loop at most companies follows a familiar pattern: a phone screen with a recruiter, a coding challenge involving data structures and algorithms, one or two system design rounds, and a "culture fit" conversation that's really just a vibe check.

This process optimizes for a specific skill: the ability to solve abstract algorithmic problems under time pressure while being watched. That skill has almost no correlation with the day-to-day work of building production software. It does, however, correlate strongly with having leisure time to practice competitive programming, having attended a university with a strong algorithms curriculum, and being comfortable performing under artificial social pressure.

The result is a process that systematically advantages a narrow demographic while filtering out exceptional engineers who happen to be nervous interviewers, career-changers, or self-taught developers who never took an algorithms course.

I realized we needed to start from a different question: what does a great engineer actually do in their first 90 days at our company?

Defining What We're Actually Looking For

Before redesigning the process, I assembled a working group of our strongest engineers — not just senior people, but engineers across levels who were widely recognized as exceptional contributors. I asked them a simple question: "What skills and qualities make someone successful here?"

The answers were remarkably consistent. Great engineers at our company could read and understand unfamiliar codebases quickly. They could take a vague product requirement and translate it into a technical design that balanced pragmatism with quality. They communicated clearly about trade-offs. They asked good questions. They were collaborative without being deferential. And they cared deeply about the craft of building software — not as an abstract intellectual exercise, but as a practical discipline.

Nowhere on the list was "can implement Dijkstra's algorithm on a whiteboard in 25 minutes."

Stage One: The Async Take-Home

Our process starts with an asynchronous take-home exercise. I know some engineers dislike take-homes, and I understand the criticism — they can be time-consuming and feel like free labor. We've designed ours to address these concerns directly.

The exercise is scoped to take no more than three hours. We tell candidates this explicitly and mean it. The problem is a simplified version of something our engineers actually build — a small service that ingests data, applies business rules, and exposes an API. There's no single correct solution. We're interested in how candidates structure their code, handle edge cases, write tests, and document their decisions.

Candidates receive the exercise and have one week to complete it at their convenience. They can use any language, any framework, any tools. They can use Google, Stack Overflow, AI assistants — whatever they'd use in their actual job. We're not testing memorization; we're testing engineering judgment.

Every submission is reviewed blindly. We strip names, universities, and company histories before the reviewing engineers see the code. This was one of the most impactful changes we made. In our first year with blind review, we advanced candidates from non-traditional backgrounds at nearly double the previous rate, and those candidates performed equally well in subsequent stages.

Stage Two: Code Review Conversation

Candidates who pass the take-home don't move to a new coding challenge. Instead, they join a 60-minute video call with two of our engineers to discuss their submission. This conversation simulates a real code review — one of the most important activities in any engineering organization.

The interviewers have already reviewed the submission and prepared questions. "I noticed you chose to handle validation at the controller layer rather than the model layer — walk me through that decision." "Your error handling strategy differs between these two modules — was that intentional?" "If this service needed to handle 100x the traffic, what would you change first?"

This format reveals more about an engineer's thinking than any whiteboard exercise ever could. We see how they reason about trade-offs, how they respond to constructive feedback, how they explain their decisions, and whether they can recognize the limitations of their own work. The best candidates light up during this conversation — they enjoy the technical discourse and engage as peers.

It also gives candidates a genuine preview of our engineering culture. They experience what it's like to discuss code with our team. Several candidates have told us this round was the deciding factor in accepting their offer — they could tell from the conversation that our engineers were thoughtful, collaborative, and genuinely interested in the craft.

Stage Three: System Design as Collaboration

Our system design round is explicitly collaborative, not evaluative in the traditional sense. The candidate receives a problem statement 24 hours in advance — something like "Design a notification system that supports email, SMS, and push notifications with user preference management and delivery tracking."

During the 75-minute session, two engineers work through the design with the candidate. Not watching them design. Working with them. The interviewers ask questions, suggest constraints, push back on decisions, and add requirements incrementally — just like a real design discussion in our planning process.

We evaluate candidates on several dimensions: Can they break down an ambiguous problem into manageable components? Do they identify the right trade-offs and articulate them clearly? How do they respond when constraints change? Do they ask clarifying questions or make assumptions silently? Can they reason about scale, failure modes, and operational concerns?

The collaborative format is essential. Engineering is a team activity. A brilliant architect who can't collaborate on a design is less valuable than a good architect who makes the entire team better through discussion. This round surfaces that distinction clearly.

Stage Four: The Values Conversation

Our final round is what we call the "values conversation," and it's the one I'm most proud of. It's not a culture fit check — "culture fit" too often means "someone I'd want to get a beer with," which is a bias machine. Instead, it's a structured discussion about engineering values and professional philosophy.

An engineering manager and a peer-level engineer ask questions like: "Tell me about a time you disagreed with a technical decision that had already been made. How did you handle it?" "Describe a situation where you had to balance shipping quickly against building something you were proud of." "How do you approach giving feedback to someone more senior than you?"

We score responses on a rubric aligned with our engineering values: ownership, intellectual honesty, collaborative leadership, and craft. The rubric is specific enough to be consistent across interviewers but flexible enough to account for different communication styles and cultural backgrounds.

We also explicitly carve out time for candidates to ask questions — not as a formality, but as a genuine evaluation signal. The questions a candidate asks reveal what they care about, what concerns them, and how they evaluate an organization. Engineers who ask about deployment practices, team autonomy, and how decisions are made tend to be the ones who thrive in our environment.

What We Stopped Doing

Equally important to what we added is what we removed. We eliminated all algorithm puzzle rounds. We stopped asking brainteaser questions. We eliminated any round where a candidate writes code while being watched in real-time, because the anxiety of live observation distorts performance in ways that don't predict job success.

We also eliminated the debrief dynamic where a single "no" from any interviewer vetoes the candidate. Our previous process allowed a single negative score to sink an otherwise strong candidate. Now we use a structured calibration discussion where every interviewer presents their assessment, and we evaluate the complete picture. A concern from one round might be outweighed by exceptional strength in another.

The Results

In the two years since we redesigned our process, our metrics have improved across every dimension we track. Offer acceptance rate increased from 68% to 84%. First-year retention improved from 79% to 93%. Performance reviews for new hires show stronger ratings at the six-month mark compared to the previous cohort.

Most importantly, our team is more diverse — in background, in experience, in thinking style. We're hiring engineers from bootcamps alongside engineers from top computer science programs, and they're both succeeding. We're hiring career-changers who bring domain expertise from other industries. We're hiring people who are exceptional builders even if they're not exceptional interviewees.

The Ongoing Investment

This process requires more effort than a standard interview loop. The take-home review takes time. The collaborative rounds require interviewers to prepare. The calibration discussions are longer than a simple thumbs-up-thumbs-down debrief. We invest in interviewer training — every new interviewer shadows three rounds before conducting one, and we regularly calibrate our scoring rubrics.

But hiring is the highest-leverage activity in any engineering organization. Every engineer you hire shapes your culture, your codebase, and your capacity for years. Investing an extra few hours per candidate to dramatically improve your signal is not a cost. It's the most valuable investment you can make.

The engineers we've hired through this process are builders. They ship software that works, they elevate the people around them, and they care about doing excellent work. That's what we were looking for all along — we just needed an interview process worthy of finding them.