Secrets of fast programs: when every nanosecond counts by Ivan Petrushenko | JavaDay Lviv 2025

Описание: Talk “Secrets of fast programs: when every nanosecond counts” by Ivan Petrushenko Founder at CS Osvita | Engineering Lead at SQUAD.

We’ll explore powerful #algorithm optimization techniques and how low-level knowledge, like #CPU architecture and cache behavior, can dramatically speed up code. You’ll see why algorithms with the same complexity can perform differently, and how to optimize for cases where every nanosecond matters.

Agenda:👇
00:00 - Intro & Topic Overview
05:46 - Processor evolution and instruction timings
09:09 - Cost of arithmetic operations and branch prediction
13:15 - Memory hierarchy and access speeds
16:55 - Example 1: Optimizing neural network training code
25:05 - Example 2: Optimizing digit count function
28:47 - Example 3: Hash table implementation optimizations
35:16 - Example 4: Sorting algorithms and cache effects
41:01 - Example 5: Image processing and memory access patterns, branch predictions
51:50 - Example 6: Memory usage optimization with pointer tagging
54:57 - Conclusion and Q&A session


JavaDay Lviv is an annual international conference related to Java technologies and eco-system. Propose more than 18 global speakers – well-known Java professionals from the different countries around the globe. The conference agenda will include trends, hypes and cutting-edge technologies, such as Full-stack Java, JVM Languages, Serverless, Machine Learning, Data Science and much more.

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