By Mockly English · Last updated:
Strong engineers still stall when they have to think and speak English at the same time. He was a security engineer in the United States. The gap was system design — not the technical content.
At a glance
| Role | Security Engineer |
|---|---|
| Location | United States |
| English challenge | system design |
| Interview problem | System Design |
| Target | |
| Preparation | Live mocks with English feedback on the same answers |
| Outcome | Gained clearer, more confident English for interviews |
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Strong engineers still stall when they have to think and speak English at the same time. He was a security engineer in the United States. The next interviews were at Google, in English. When he had to explain a system design out loud, his answers lost structure and he paused to translate.
Practice matched the round he actually had to speak: system design for Google. After each mock, he got notes on the same answer — where he paused, which words were vague, and where the structure broke.
Useful references along the way: What to expect in English interviews, Pronouncing numbers and metrics.
System design is a 30–45 minute spoken explanation. You must sequence components, defend trade-offs, handle follow-ups, and keep vocabulary accurate while the clock runs. Translating each sentence in your head uses the time the interviewer needed for depth. A fixed spoken order is what keeps the round coherent in a second language.
Preparing for a similar path? Read How a Croatian Security Engineer Prepped for Google's Behavioral Interviews.
He gained clearer, more confident English for interviews. He could explain the work more clearly when questions got hard. That readiness was the goal — not a promised job offer.
He prepared for English-language interviews as a security engineer. Written English was stronger than speaking against the clock.
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Learn the language of the round you will face. For him, that meant system design spoken in full sentences — requirements, metrics, and trade-offs — not a general business-English course.
That was his pattern: written English was stronger than live answers. Practise system design out loud until follow-up questions no longer break your structure.
Use one spoken order every time (requirements, scale, architecture, trade-offs) and reuse it. Translating each sentence is what makes you jump between components.
No. Clarity and structure matter most. A light accent is fine if interviewers can follow your decisions and numbers.

Mockly’s approach is genuinely personalized — they use a variety of methods tailored to your specific needs. With their help, I improved my spoken English and prepared thoroughly for behavioral interview questions across different companies. This not only helped me refine my stories grammatically but also ensured I was using the right examples to answer specific questions effectively.

I’ve had the pleasure of practicing English with Mockly and I truly appreciate the progress I’ve made. I highly recommend their services to professionals in tech and beyond. I particularly enjoy the teaching style and the philosophy behind it: “If you enjoy the process, you’ll get it.” The personalized learning plans make every session practical and useful. Their hands-on knowledge and genuine interest in the world of technology will genuinely boost your English skills.
A Croatian security engineer was targeting Google. Behavioral stories in English were the gap. Here is what she practised.
A software engineer in Germany was preparing for a Google behavioral interview in English. Here is the practice that changed the delivery.
Case studies are illustrative, based on patterns from real coaching sessions.