Low-Latency Fundamentals

Every microsecond counts, but where do they actually go?

This article traces the hidden journey of a message from the network wire to the application's code, revealing how the NIC, interrupts, syscalls, and runtimes introduce delay at every hop.

Learn how to pinpoint where time disappears in Python systems, from CPU and I/O bottlenecks to Prometheus metrics and continuous profilers. Explore the tools that turn raw measurements into observability dashboards revealing real performance patterns.

Low-latency systems fail when work becomes unbounded. Batching, conflation, and backpressure are mechanisms that keep systems stable under bursty, adversarial load. Without them, tail latency and cascading failures are inevitable.

An introduction to ring buffers, a foundational data structure for low-latency systems. We'll cover how they work, why they're fast, common variants, and practical use cases in real-time applications.