# Networks
All Networks notes →1 — Network Performance
Bandwidth vs. latency, bufferbloat, tail latency, and head-of-line blocking as the performance concepts that separate a fast network from a merely working one.
2 — Connection Management
Connection pools, keep-alive, timeouts, retries, and circuit breakers as the client-side levers for managing unreliable network connections.
3 — Compression
gzip, Brotli, and HTTP compression as the payload-optimization techniques that trade CPU for bandwidth.
4 — Caching
Browser cache, CDN cache, reverse-proxy cache, and application cache as the layered caching strategy behind most low-latency systems.
5 — Network Benchmarking
iperf, wrk, k6, Vegeta, and tc as the tools used to actually measure and simulate network performance.
# Sre
All Sre notes →1 — Performance Fundamentals
Latency, throughput, and utilization as the three numbers that describe any system's performance — and why optimizing one in isolation usually degrades another.
10 — Soak Testing
Running sustained load over hours or days to surface the failure modes — memory leaks, connection exhaustion, log disk fill — that only appear over time.
11 — Capacity Testing
Finding the actual ceiling of a system's current configuration, which is the number capacity planning is supposed to be forecasting against.
12 — Performance Bottlenecks
Why a system's bottleneck moves once you fix the current one, and the systematic method for finding the next constraint instead of chasing symptoms.
13 — Performance Optimization
Measure first, optimize the actual bottleneck, measure again — the discipline that keeps performance work from becoming expensive, unmeasured guesswork.
2 — CPU Profiling
Sampling vs. instrumenting profilers, and reading a flame graph to find the function actually burning cycles instead of guessing from intuition.
3 — Memory Profiling
Heap growth, allocation patterns, and the leak-hunting workflow for the class of bug that only shows up as a slow, inevitable OOM hours into a service's uptime.
4 — Disk Performance
IOPS, throughput, and queue depth as the metrics that separate a genuinely disk-bound service from one that just looks that way in a dashboard.
5 — Network Performance
Bandwidth, latency, and packet loss as distinct failure signatures, and the tools that tell you which one is actually behind a 'the network is slow' report.
6 — Benchmarking
Designing a benchmark that measures what production actually does, not what's convenient to measure — and the methodology gaps that make most benchmarks lie.
7 — Load Testing
Validating a system behaves correctly at expected peak traffic, and the difference between a load test that proves capacity and one that just proves the test ran.
8 — Stress Testing
Pushing a system past its expected limits to find where and how it breaks — the failure mode, not just the breaking point, is the actual finding.
9 — Spike Testing
Testing a system's response to sudden, extreme traffic jumps — the autoscaling lag and cold-start behavior that a gradual ramp-up test never exposes.