How a European Backend Engineer Interviewed at Revolut in English

The Problem

Interviewers are not grading your accent. They need to follow your reasoning in English. She was a backend engineer in London. The next interviews were at Revolut, in English. In the room, system design was what broke down.

Then vs Now

What We Practised

Practice matched the round she actually had to speak: system design for Revolut. Each mock got notes on the same answer — where she paused, which words were vague, and where the structure broke.

• Practised clarifying requirements before naming services
• Used a fixed explanation sequence: scope → components → bottlenecks → trade-offs
• Practised explaining trade-offs aloud, not only drawing boxes
• Worked on metrics and numbers in English (latency, load, cost)
• Narrated architecture without stopping to translate each sentence

Useful references along the way: STAR interview framework, What to expect in English interviews.

A Key Change

The shift showed up in a timed system-design mock. She knew the architecture but jumped between components. A fixed spoken sequence — requirements, then scale, then architecture, then bottlenecks — was repeated until follow-ups stayed inside that order.

What to Practise

• Clarify scope before you name services.
• Use one spoken sequence every time: requirements → scale → architecture → bottlenecks → trade-offs.
• Practise saying metrics (latency, QPS, storage) in full sentences.
• Name one trade-off out loud even if you are sure about the design.
• Record a 15-minute walk and listen only for jumps and unfinished sentences.

After the Coaching

Improved speaking confidence toward interview and IELTS goals. She could explain the work more clearly when questions got hard. That readiness was the goal — not a promised job offer.

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 Croatian PM Prepped for Revolut's Behavioral Interviews.

Where She Started

She prepared for English-language interviews as a backend engineer. English started around B2. Written English was stronger than speaking under the clock.