Game Developer Interview Questions UK: 8 Real Questions and What Interviewers Want

Most Game Developer interviews in the UK follow a pattern, and knowing it beats guessing. Below are eight questions from our bank of 16, each with a note on what the interviewer is really after.

Eight Game Developer interview questions, and what the interviewer is thinking

1. Can you explain the game loop and the difference between fixed and variable time steps?

Why they ask: It tests foundational understanding of how real-time games update and render.

2. How do you profile and optimise a game that is running below its target frame rate?

Why they ask: Performance is a central concern across platforms from mobile to console.

3. Explain how you would implement basic enemy AI, and what techniques you know such as state machines, behaviour trees and pathfinding.

Why they ask: AI is a common gameplay programming topic with several accepted approaches.

4. What is the difference between Unity and Unreal Engine, and how do you decide which to use?

Why they ask: Most UK studios use one of the two, so they want to see pragmatic engine knowledge.

5. How do you handle memory management and garbage collection issues in a game?

Why they ask: Hitches from memory behaviour are a classic game performance problem.

6. Playtesters say a mechanic you built feels unresponsive, but the code is working as designed. What do you do?

Why they ask: Game feel is subjective, and a developer must handle feedback from design and players.

7. Tell me about a time you built or improved a gameplay system that players or testers responded well to.

Why they ask: They want evidence of shipping features and responding to feedback.

8. Why do you want to be a game developer, and what games or technology have inspired you?

Why they ask: Studios look for passion, awareness of the industry and realistic expectations.

A sample answer to question 1

Can you explain the game loop and the difference between fixed and variable time steps?

A game loop repeatedly processes input, updates the simulation and renders a frame. With a variable time step, each update is scaled by delta time, the time since the last frame, which is simple but can make physics unstable and non-deterministic, because a long frame produces a large step that might tunnel objects through walls. A fixed time step runs the simulation at a constant interval, say sixty updates per second, using an accumulator to run zero or more updates per rendered frame, which makes physics, networking and replays deterministic. Rendering then interpolates between the previous and current states for smoothness. In Unity I'd use FixedUpdate for physics and Update for per-frame logic, and in Unreal, tick groups and substepping. I also clamp the maximum frame time to avoid the spiral of death, where a slow frame causes more updates, making the next frame slower still.

Common mistake to avoid: Multiplying everything by delta time without considering physics; ignoring frame-rate independence

Want the rest?

Full model answers, key points and common mistakes for all 16 questions are on the Game Developer interview questions page. The first five are free, no sign-up needed.