Skip to main content
Beginner~2h

Inference Fundamentals in AI Inference & ServingInterview Readiness Check

Prefill vs decode phase, autoregressive generation, memory bandwidth vs compute bound regimes, roofline model for LLMs, FLOP counts, and why inference is harder than training..

prefilldecodeautoregressivememory bandwidthroofline modelFLOPinference bottleneck

Learning path

Try a sample question

During LLM inference, a 7B parameter model processes a 512-token prompt and generates 256 tokens. Which phase is most likely to be compute-bound rather than memory-bandwidth-bound?

A.The decode phase, because each token generation requires a full forward pass loading all weights
B.Both phases are equally memory-bandwidth-bound due to KV cache reads dominating attention
C.The prefill phase, because the entire prompt is processed in a single large matrix multiplication
D.Neither phase is compute-bound on modern GPUs with FP16 precision due to memory bottlenecks

Sign up free to take the full check and see the answer with an explanation.

What this module tests

  • Conceptual understanding of inference fundamentals fundamentals
  • Trade-offs and design decisions in real system scenarios
  • prefill and decode — applied knowledge
  • Interview-style reasoning and explanation quality

Free to start

Take the Inference Fundamentals check →

10 questions · Dimension scoring · AI coach feedback · Shareable result

Test your knowledge — free →

No credit card · Takes 10–15 min

Frequently asked questions

What does the Inference Fundamentals check test?
The check covers prefill vs decode phase, autoregressive generation, memory bandwidth vs compute bound regimes, roofline model for llms, flop counts, and why inference is harder than training.. Questions span beginner to advanced difficulty and test both conceptual understanding and practical trade-off reasoning.
What keywords should I know for Inference Fundamentals?
Key concepts include: prefill, decode, autoregressive, memory bandwidth, roofline model, FLOP, inference bottleneck. These frequently appear in ai inference & serving interviews at product and infrastructure companies.
How many questions are in the check?
Each check has 10 questions — a mix of MCQ and short-answer. You get scored by dimension (e.g., scalability, consistency) so you know exactly where to focus.
How long does it take to study Inference Fundamentals?
Most engineers spend around 2 hours on this module. The check itself takes about 10–15 minutes. You can retake it up to 3 times per day.
What prerequisite knowledge do I need before Inference Fundamentals?
Inference Fundamentals is a foundational module — no prerequisites needed.
Is prefill, decode, autoregressive covered?
Yes. The Inference Fundamentals module covers prefill, decode, autoregressive among other key concepts. The check includes questions that reflect real ai inference & serving interview patterns.

What this unlocks