Warm and toasty

Understanding cache warming in low-latency systems

This question tests your grasp of CPU cache behaviour and how it affects real-world application performance. Cache warming is a fundamental optimization technique in latency-sensitive domains like high-frequency trading, where microseconds matter and predictable execution time is critical.

To answer this well, you need to understand what happens when data or instructions are not yet in the cache, how modern CPUs handle cache misses, and what practical strategies exist to pre-load or pre-position frequently-accessed memory into the cache hierarchy before a performance-critical code path runs. The concept bridges system architecture, memory hierarchy design, and performance engineering.

• CPU cache levels (L1, L2, L3) and their latencies
• Cache miss penalties and stalls
• Memory access patterns and prefetching
• Predictability in tight loops and trading systems