Is scala code slow?

on YouTube ↗50m

" summary

Claims are concrete: a one-line Scala rewrite can be measurably slower (author shows a 3× example) and small edits yield 4–7× gains. Demonstrations include JMH and perf-guided assembly dumps, HotSpot behaviours like loop unrolling at 16, bytecode vs assembly for pattern matching and tail calls, and collection pitfalls where boxing causes gigabytes/sec of GC churn. Examples compare while loops, pattern match, tail recursion and Scala collections across Scala 2.11/2.12 so you see what was built and what actually worked.

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" chapters (14)

1. 0:00Start
2. 4:28HIT THE COMPILE BUTTON
3. 7:17IF VS PATTERN MATCHING
4. 12:09WHAT ABOUT OPTIONS?
5. 15:52MEET FIBONACCI
6. 17:49BYTECODE TO THE RESCUE!
7. 18:15FIBONACCI WITH TCO
8. 24:39LOOP UNROLL
9. 30:07LOOP PERF COUNTERS
10. 30:49LIST VS ARRAY
11. 32:23GC PROFILING RESULTS
12. 32:43APPLES VS ORANGES
13. 35:522.11 DESUGARED
14. 41:07THE END

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