When preparing for a technical interview, the biggest fear isn’t that you can’t solve the problem — it’s that your mind might go blank under pressure. Even if you’ve solved hundreds of LeetCode problems, a single unexpected follow-up or moment of silence can throw everything off.

This is especially true at companies like TikTok, where interviewers don’t just test whether your code works — they want to see how clearly you can explain your thinking, how stable you are under pressure, and whether you’ve thought through edge cases. This real interview story is about how one candidate used CSOAHELP’s real-time, silent live assistance to navigate a TikTok interview — and walked away with high praise from the interviewer.

The interview began with a straightforward question:

Calculate the IoU Filter During Detecting
Input:

[[x, y, width, length, label, conf]...]  

The task was to compute the Intersection over Union (IoU) for multiple detection boxes and implement a Non-Maximum Suppression (NMS) algorithm to retain the optimal results.

This candidate was familiar with the concept, having solved similar problems during preparation. But when the interviewer asked, “Can you start by implementing the IoU function and walk me through your logic?” — he froze.

At that moment, he could’ve spiraled. But he had something others didn’t: he had already booked a session with CSOAHELP’s real-time technical interview support.

As the candidate hesitated to organize his thoughts, CSOAHELP’s live prompt window on his secondary device immediately displayed the following:

“I’ll begin by writing a calculate_iou function that takes two bounding boxes in [x, y, width, height] format. I’ll convert both boxes into (x1, y1) and (x2, y2) coordinates, representing the top-left and bottom-right corners. Then I’ll compute their intersection area, and use that along with the union area to calculate the IoU. If there's no overlap, the IoU will be zero.”

Right after, CSOAHELP also pushed the complete code template he could type out while explaining:

def calculate_iou(box1, box2):
    # Convert to top-left and bottom-right coordinates
    x1_min, y1_min = box1[0], box1[1]
    x1_max, y1_max = box1[0] + box1[2], box1[1] + box1[3]
    
    x2_min, y2_min = box2[0], box2[1]
    x2_max, y2_max = box2[0] + box2[2], box2[1] + box2[3]

    # Calculate intersection
    inter_x_min = max(x1_min, x2_min)
    inter_y_min = max(y1_min, y2_min)
    inter_x_max = min(x1_max, x2_max)
    inter_y_max = min(y1_max, y2_max)

    inter_width = max(0, inter_x_max - inter_x_min)
    inter_height = max(0, inter_y_max - inter_y_min)
    inter_area = inter_width * inter_height

    # Calculate union
    area1 = box1[2] * box1[3]
    area2 = box2[2] * box2[3]
    union_area = area1 + area2 - inter_area

    return inter_area / union_area if union_area > 0 else 0

The candidate typed and spoke at the same time. The interviewer nodded, “Looks good — let’s move on to implementing NMS.”

This was the crucial moment. The interviewer now wanted a function that performs class-aware NMS: filtering out lower-confidence boxes that overlapped significantly with higher ones, within the same label.

The candidate paused again. But CSOAHELP was already pushing a full explanation and code block to his side screen.

“I'll sort all detection boxes in descending order by confidence. Then I’ll use a while loop to take the highest-confidence box each time, add it to the result list, and compare it with the rest. If another box has a different label, I’ll skip the comparison. If the label is the same, I’ll calculate IoU and remove boxes whose IoU exceeds the threshold. I repeat this until no boxes remain.”

Here was the exact implementation the candidate typed out:

def apply_nms(detections, iou_threshold=0.5):
    detections = sorted(detections, key=lambda x: x[5], reverse=True)
    kept = []

    while detections:
        best = detections.pop(0)
        kept.append(best)
        remaining = []

        for det in detections:
            if det[4] != best[4]:
                remaining.append(det)
                continue

            iou = calculate_iou(best[:4], det[:4])
            if iou < iou_threshold:
                remaining.append(det)

        detections = remaining

    return kept

The candidate explained the logic calmly and confidently while typing. He even added, “This process can be scaled using multiprocessing or GPU acceleration if we're handling real-time detection with a high volume of boxes.”

The interviewer replied, “This is a very clean implementation. Nice explanation too.”

After the call, the candidate’s first message to us was: “That was smooth. I just read the prompt you gave me and stayed calm.”

The reality is, without this combination of real-time guidance, pre-built structure, and code patterns, most candidates would falter somewhere — either in coordinate conversion, loop structure, or explanation. But with CSOAHELP running silently in the background, this candidate stayed on track and delivered a top-tier answer. The interviewer had no clue he was being supported — because the candidate was doing the speaking, typing, and thinking in real time. We just helped him not trip over his own nerves.

So, who is CSOAHELP really for? If you’re interviewing for TikTok, Google, Meta, or Stripe, and you know your stuff but tend to get flustered in high-stakes interviews — we’re your secret weapon.

If you freeze during coding rounds, we guide you through each step — live. If you struggle to communicate clearly in system design, we help you structure your thought process. If behavioral questions throw you off, we help you apply the STAR method on the fly. And if English isn’t your first language, we give you concise, well-phrased prompts you can read aloud without sounding robotic.

We’re not here to cheat for you. We don’t write your code. We don’t fake your experience. We’re your invisible partner — engineers and ex-interviewers who help you show the best version of your technical self.

Most candidates who fail do so because of poor communication, stress, or forgotten details — not because they lack knowledge. With CSOAHELP, we ensure your true abilities come through loud and clear, in every interview.

If you’ve spent months preparing and don’t want to risk it all over one rough 45-minute session, then now is the time to consider CSOAHELP.

Curious about our live interview support service? DM us or leave a comment — we’ll match you with a dedicated assistant, customize your prompt set based on your target company, and rehearse it with you until you’re ready for anything.

Next up: how a candidate used CSOAHELP to walk through a full distributed system design for Stripe’s payment routing infrastructure — and nailed the round. Stay tuned.

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.