"Have Uber interviews become easier?" That's the question on the minds of many engineers looking to switch roles — from big tech insiders to international students returning from overseas.

At first glance, the problem doesn’t look like a dynamic programming brain-twister or a complex system design challenge. It reads —

"You're given an R-by-C array of integers that represents a top-down map of a building construction site..."

In short: you're given a construction site represented by a 2D grid of 0s and 1s. A 1 indicates a building block, and a 0 means empty land. You’re asked to return the perimeter of the building.

Sounds simple, right? Almost like a primary school math problem. But the traps are subtle and real. Our client — the main character in this case — was preparing for a systems engineering position at Uber and nearly tripped up on this very question. Thankfully, they contacted CSOAHELP a few days before the interview and, with our real-time remote interview support, made it through to Uber’s final round.

The first time the candidate saw the problem, they chuckled. "Isn’t this just counting the edges around each 1?" Their instinct was: "For every 1, add 4, then subtract for any neighboring 1s above, below, left, or right."

While this approach works in principle, they failed to clearly explain edge handling, and didn’t consider special shapes like enclosed courtyards or disconnected islands. They also missed whether the building is contiguous.

Our remote assistant team immediately pushed a note to the client’s secondary device (an iPad in front of them): "You can explain that your approach is to iterate over the grid. For each cell with a 1, you assume 4 sides, then check the four directions. For each adjacent 1, you subtract a side. Be sure to mention handling of boundary cases and using a direction array to avoid index errors."

The candidate smoothly repeated this reasoning, stayed calm, and earned a nod from the interviewer.

Then came the follow-up — just two minutes later, the interviewer smiled and shared a new input:

[[1, 1, 1], [1, 0, 1], [1, 1, 1]]

"There’s a hole in the middle. Is your calculation still correct?"

Now the candidate was rattled. They knew the result wouldn’t be the same, but couldn’t pinpoint the exact problem. They mumbled, "Uh… I think I forgot about inner voids..."

We instantly pushed another hint to their device: "You can say that this is a hollow structure — the inner 0 shouldn’t be treated as outside air. But your method works as long as you only process 1s and ignore 0s. Just clarify that internal holes don’t impact the subtraction logic, as you only check 1s."

The candidate quickly responded, "Actually, this still follows my earlier logic. I ignore whether a 0 is inside or outside. As long as it’s not a 1, I don’t subtract a side. I just check if the 1 has neighboring 1s; if not, I keep the edge."

This reply was clear, correct, and demonstrated understanding of algorithm boundaries. The interviewer smiled again and kept going.

"What happens if the grid is 10,000 by 10,000?"

The candidate hesitated, voice slowing. They guessed it was O(N*M) time complexity but worried that might sound inefficient. They paused.

We quickly sent this message: "You can say: each cell is only visited once. At most four checks per 1, so the time complexity is O(R*C), which is linear. Space is O(1) aside from loop variables or a direction array. Ideal for large-scale input."

The candidate repeated: "This algorithm runs in O(R*C) time because each cell is visited once. Checking four directions is constant time. It uses almost no extra space, just some counters or arrays — so it handles large matrices well."

This time, the interviewer gave a direct nod: "Great, that’s clear."

Interestingly, this tech round didn’t require full code implementation. The real focus was the candidate’s ability to model the problem, think through edge conditions, and explain everything clearly under pressure.

And this is exactly where most candidates falter. Even if you’ve solved hundreds of problems, the moment someone asks, "Why this approach? Could this scale to production?" many freeze.

That’s why CSOAHELP’s real-time remote interview support exists.

During the entire interview, we continuously analyzed the conversation and pushed clear, high-density text prompts to guide the candidate’s answers. For algorithm questions, we offered outline logic or pseudo-code when needed. All they had to do was speak or write it out naturally. For moments of confusion, language block, or mental gaps, we provided phrasing structures: how to start an answer, how to transition, how to summarize. When the interviewer raised deeper engineering questions — like performance or real-world scaling — we had templates prepared, guiding the client subtly without any visible interference.

This support system proved invaluable during the Uber interview.

Interviews are high-pressure, unpredictable, and often filled with curveballs. We’ve seen countless smart engineers miss out on dream offers just because they couldn’t express themselves clearly, or lost track under pressure.

CSOAHELP’s real-time support is built exactly for those moments.

We don’t cheat or pretend to be you. We’re your second brain — helping you organize, clarify, and articulate your real skills with precision.

You do the preparation. We make sure it lands.

If you’re facing upcoming interviews with Uber, Google, Apple, Stripe, or other top-tier companies, don’t go it alone.

Get in touch. Discover your personalized support strategy.

You no longer have to face interviews solo. You can bring a team to the table — quietly, effectively, and powerfully.

经过csoahelp的面试辅助，候选人获取了良好的面试表现。如果您需要面试辅助或面试代面服务，帮助您进入梦想中的大厂，请随时联系我。

If you need more interview support or interview proxy practice, feel free to contact us. We offer comprehensive interview support services to help you successfully land a job at your dream company.