Latency vs Throughput vs Bandwidth Explained: The Real Difference

Latency vs throughput vs bandwidth: learn to diagnose which one is actually broken before you optimise the wrong thing. Full lesson with diagrams, code and interview questions: https://algoinsight.io/courses/system... Engineers often say a system is 'slow' without specifying what they mean, and that confusion wastes effort. This lesson separates latency (time for one request, in milliseconds), throughput (requests per second), and bandwidth (the size of the pipe, in gigabits per second) using a highway analogy. You'll see why averages lie - a p99 of 500ms and p99.9 of 8 seconds hide real pain - and learn Jeff Dean's latency numbers, from an L1 cache reference at half a nanosecond to a cross-continent round trip at 150 milliseconds. A connection-pool story shows how throughput problems masquerade as latency problems. What you'll learn: Distinguish latency, throughput and bandwidth using a highway analogy Diagnose slow systems with percentiles instead of misleading averages Memorise Jeff Dean's latency numbers, from L1 cache to cross-continent trips Explain why latency rises sharply as throughput nears maximum capacity Identify when bandwidth, not latency, is the real bottleneck Recognise queueing as a throughput problem disguised as latency Apply the diagnostic table to find whether latency, throughput or bandwidth is broken Chapters: 0:00 Welcome 0:33 The three numbers 1:42 Latency 3:38 Throughput and bandwidth 7:21 Check yourself Key concepts: Latency, Throughput, Bandwidth, Percentiles (p50, p99, p99.9), Jeff Dean's latency numbers, Connection pool saturation, Queueing, CDN caching, Utilisation and capacity planning Who this is for: Engineers preparing for system design interviews who need to diagnose whether latency, throughput or bandwidth is the real bottleneck. The full course, System Design Fundamentals: https://algoinsight.io/courses/system... Practise interviews with AI: https://algoinsight.io/interview?utm_... Plan your prep, day by day: https://algoinsight.io/planner?utm_so... About AlgoInsight AlgoInsight is your mentor from prep to offer: animated video lessons, DSA practice with hints and AI code review, AI mock interviews for every round, and a day-by-day prep plan built around your interview date. Start free: https://algoinsight.io/?utm_source=yo... Subscribe for more animated lessons like this. #LatencyVsThroughput #SystemDesign #TechInterview #SoftwareEngineering