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WHY PYTHON
IS SLOW?

If Python is slow… why do companies still use it?

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Let's find out ↓

The Numbers

A Simple Benchmark

python

Execution Time

0.0
Seconds

"Why is Python so slow?"

Comparison

The Same Program in C

c
long long s = 0;for(int i=0; i<100000000; i++)    s += i;

Execution Time

0.1
Seconds
Python is 68× Slower

Under the Hood

What Actually Happens?

The Core Reason

Compiled vs Interpreted

C
Source Code
↓
Machine Code
↓
CPU
Python
Source Code
↓
Bytecode
↓
Python VMExtra Layer = Extra Work
↓
CPU

Reason #2

Dynamic Typing

python

Python allows any type, any time

int: 5
memory block

But… how?

Reason #3

Everything Is An Object

python
x = 5

Zoom into memory →

PyObject

ob_refcnt1
ob_type*int
ob_digit5
metadata{...}

Even integers carry all this overhead

Reason #4

The GIL

Global Interpreter Lock

🔒

Only ONE thread can execute Python bytecode at a time.

Running
Thread 1
Waiting
Thread 2
Waiting
Thread 3
Waiting
Thread 4

The Secret

Then Why Is Numpy Fast?

🐍 Python
↓
NumPy
↓
⚡ C
↓
CPU

The Secret

Heavy computations
run in C, not Python.

100×
Faster than pure Python

The Future

Can Python Become Faster?

Speed Comparison

CPython
CPython
PyPy
PyPy

PyPy Pipeline

JIT Compiler
↓
Machine Code

Hot code becomes machine code
at runtime.

Reality Check

Python Is Not Slow

Pure Python Loops = Slow

But real Python uses:

Where speed comes from

NumPy
C
Pandas
C
TensorFlow
C++
PyTorch
C++
FastAPI
I/O

The Real Answer

Why Do Big Companies
Use Python?

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Why Python Wins

Runtime Speed

C/C++
Java
Python

Developer Speed

C/C++
Java
Python

Full Deep Dive

Watch the Complete Video

Everything we covered — animated, explained, and more.

Python is slow

where raw speed matters.

Python is powerful

where ideas matter.

And in the real world…

Ideas shipped faster often win.

Thanks For Watching 🎬

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