How a Non-Native Speaker Handled Wise's System Design Round
Strong engineers still stall when they have to think and speak English at the same time. She was an engineering manager in Brazil. The gap was system design - not the technical content.
What this case shows
A Brazilian engineering manager was targeting Wise. The gap was system-design answers in English - not the technical work. Here is what she practised.
At a glance
| Role | Engineering Manager |
|---|---|
| Location | Brazil |
| English challenge | system design |
| Interview problem | System Design |
| Target | Wise |
| Preparation | Live mocks with English feedback on the same answers |
| Outcome | Gained clearer, more confident English for interviews |
Candidate Snapshot
She prepared for English-language interviews as an engineering manager. Written English was stronger than speaking against the clock.
The Interview Problem
Strong engineers still stall when they have to think and speak English at the same time. She was an engineering manager in Brazil. The next interviews were at Wise, in English. When she had to explain a system design out loud, her answers lost structure and she paused to translate.
Interview Strategy
Practice matched the round she actually had to speak: system design for Wise. After each mock, she got notes on the same answer - where she paused, which words were vague, and where the structure broke.
- She practised clarifying requirements before naming services or components.
- She used a fixed spoken order: scope, components, bottlenecks, then trade-offs.
- She practised explaining trade-offs out loud, not only drawing boxes on a board.
- She worked on saying metrics and numbers in English (latency, load, cost).
- She narrated architecture without stopping to translate each sentence.
Useful references along the way: STAR interview framework, What to expect in English interviews.
After the Coaching
She gained clearer, more confident English for interviews. She could explain the work more clearly when questions got hard. That readiness was the goal - not a promised job offer.
What Other Engineers Can Learn
- Clarify the scope before you name services.
- Use one spoken sequence every time: requirements, scale, architecture, bottlenecks, then trade-offs.
- Practise saying metrics (latency, queries per second, storage) in full sentences.
- Name one trade-off out loud even if you already feel sure about the design.
- Record a fifteen-minute design walkthrough and listen only for jumps and unfinished sentences.
Why System Design Is Difficult in English
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 São Paulo Engineering Manager Prepped After a Failed Google Design Round.
Learning paths
Practise in the course
Start with your introOther engineers practising interview English
Thanks to Mockly’s preparation and mock interviews, I passed multiple interviews, received several offers, and landed a new job. The sessions increased my confidence as we worked through initial screening and technical interview questions. Mockly didn’t just improve my English - they gave me great advice on how to answer questions and approach interviews strategically. I truly recommend them to anyone seeking a role at an international company.
Mockly has been the best investment I’ve made in the past year. The mentors don’t just have a deep knowledge of the language - they bring extensive experience in the IT industry. They understand the tech job market and are well-versed in modern engineering practices and the culture of top companies. Sessions aren’t just about improving your English; they’re an opportunity to sharpen your soft skills, gain valuable insights beyond engineering, and become a stronger communicator overall. Highly recommended.
Practise explaining system design in English
No card required. Start with a 7-day free trial - a lesson, a mock interview, or both.
Join 500+ preparing for global roles
FAQ
Questions
More questions? Email us at contact@mocklyenglish.com.
Similar case studies
How a São Paulo Engineering Manager Prepped After a Failed Google Design Round
A São Paulo engineering manager failed Google’s system design round. Coaching rebuilt vocab and full-loop English, including Airbnb.
How a Bulgarian Engineering Manager Prepped for Meta in English
Explaining system-design answers while an interviewer watched was the hurdle. This engineering manager trained that skill for Meta - no offer claimed.
More case studies
Related resources
Case studies are illustrative, based on patterns from real coaching sessions.