It is 25th September 2025 when I started writing on this context of significance of C programing language in the age of AI (Artificial) and ML (Machine Learning).
The very first problem among students or learners is that they do not have clarity at all about the applications or usage of C, Python, Java or be it any programming language.
As part of curriculum we all learn C Language in our B.Tech or BCA degree but just to pass or clear the paper.
What if I tell you that I can explain the usage of C programming based on my 15 years of experience working in the industry on different real products and projects? Yes, that’s right!
But, let’s start from the step one, the very basics in understanding why, what, where and everything about ‘C’.
My intent behind writing this piece of text is to give you a clear idea about what is the importance of C programming in the modern day era where the daily usage of AI is slowly dominating in every area of life including writing software code with proper prompts.
By the end of this post you will have a very clear idea about the below things:
- Where C programming is used in the age of AI?
- How C programming is used in the underlying AI infrastructure?
- Why C language was not replaced by any other language in the industry for more than 50 years?
- Why I am confident that it is impossible to replace C language in near future even if AI is around?
Let’s start by answering all above questions one by one, but before that let’s understand in brief on how does programming work in computers.
This will help you understand C language better.
Contents
- 1 How Does a Computer Understand?
- 2 Understand the Strong Beginning of C Programming Language
- 3 Legacy of C Language Which Kept This Going for 50 Years.
- 4 How C Programming is Used in the Underlying AI Infrastructure?
- 5 Why C Language is Not Replaced in 50+ years?
- 6 Why I am Confident C Language is Irreplaceable Even after AI?
- 7 Conclusion
How Does a Computer Understand?
I will touch with a very minimal history to establish the context of invention of C language.
We understand languages such as English, Hindi, etc. and our brain associates those words to several actions or names etc.
Imagine you do not know a language to speak, but you have to show people what you want. How will you do it?
You do it by showing actions. The actions are understood by everyone regardless of words or languages.
You can think of this as a low level language.
Now, let’s say you know the words or the language as a whole. How will you tell someone what do you want?
You will say it in words. Now, the other person will understand that word, and then decode the action needed to perform and then do it.
Here, the literal languages are referred to as high level languages which is easier for humans to understand actions or anything.
Just as that.. Assembly language was one of the widely used Low level language and the C programming was the widely used high level language.
Understand the Strong Beginning of C Programming Language
Assembly language used to write machine understandable code which was basically called as instructions which looked something like the below:
main: push %rbp
mov %rsp, %rbp
lea str(%rip), %rdi
xor %al, %al
call printf
leave
retCode language: PHP (php)What do you understand from what is written above?
I know you would agree with me when I say you did not understand anything that the above text conveys.
This is what is low level assembly language. You need to write everything in great detail and exactly as the machine understands.
The problem with the assembly language is that it required a great deal of time and understanding to craft the instructions that was needed to be executed.
So, what’s the solution here?
Several high level languages were created which were written in human understandable words and those were converted to this assembly language.
Out of all those languages, C programming language had all the features required to develop usable software programs in less amount of time in comparison to other programming languages.
Let’s take a look at the below C program:
#include <stdio.h>
main ()
{
int number_variable;
number_variable = 5;
printf ("Value of the integer number_variable is %d", number_variable) ;
}Code language: PHP (php)Do you understand something out of the above code?
Of course yes, right! Let me pick up the few words or rather “keywords” that one can understand from the above code: “include”, “main”, “printf” etc.
C language was the first high level language which provided support to deal with wide data types such as floats, numbers, text or strings, provided direct access to deal with memory and underlying hardware among all other features.
I know you still have a lots of doubts but lets proceed ahead with this understanding that C language was feature rich among all other languages created around 1970s which helps dealing with real life requirements.
Legacy of C Language Which Kept This Going for 50 Years.
As I said, C language was kind of a complete programming language when it was invented and put in to the work for the first time around 1970s.
How it kept going till today for almost 50+ years is by adding more and more features via ANSI C, C99 etc. standards when needed.
I will cover more on these standards in a separate page which will make you understand how has C language evolved from the initial implementation.
Now, let me take you through the answers for all the questions I wrote about C programming.
Where C programming is used in the age of AI?
Over the period of 50+ years of time C language has still the widely used programming language in all or most of the Embedded Systems.
An embedded system is typically a device which has a system embedded inside of it. Most of the embedded systems have a Microcontroller (just like a CPU in a PC or laptop) and required hardware subsystems such as temperature sensor, wifi antenna, etc.
These hardware systems mostly run on software built on C language (or C++).
Hardware Devices Built on C Code
Some examples of embedded systems are as follows:
- Washing Machine
- Microwave Oven
- Bluetooth headphones or earbuds
- Memory card (A memory card has its own controller and a firmware)
- LED TV
- Smartwatch
- Induction Cooker
- Hard Disk Drive (HDD) or a Solid State Drive (SSD) (Yes, a Hard Disk or SSD has a firmware inside it which is written in C language)
- Wifi Chip (most of the wifi controllers found inside router or phones etc. have their own firmware inside it which runs on C language)
- Wifi Router (Typically runs on Linux)
- IP camera
- Water purifier
- and many more places
Well, YES, all those devices have one or more controllers or sensors whose software code is primarily written in C programming language or it successor C++.
Did you know before that a Hard Disk / SSD, a memory card or a Wifi chip has its own micro-controller and a firmware of its own?
I mean, these are individual systems on their own. That’s true.
I have worked on the firmware side of both the devices, that’s how I know this.
I worked for TOSHIBA company in the year 2013 on the SSD (Solid State Drive) firmware, in the year 2015 – 2017, I worked for BROADCOM in Wifi chip firmware and in the year 2018 – 19 I worked for SanDisk on a wireless storage device project.
Software Projects Built from C Code
Not just hardware, but a lot of software projects build entirely or majorly using C code.
Do you know that the biggest and largest operating system which Linux, has more than ~90% of its code written in C language?
Did you know that the first Java compiler itself was written in C language?
Let me list down several software projects written in C language:
- Operating System (Linux kernel, FreeBSD, Windows, Free RTOS, ThreadX, WindRiver Linux and many more)
- Initial Java compiler (Modern java compilers are written in Java itself)
- Database (MySQL, SQLite etc.)
- Web server (Yes, Apache and Nginx both are written in C)
- Device Drivers (most or all of the device drivers are written in C lanaguage)
- and many more
Well, if you are a student or new to B.Tech or engineering or software engineering, understanding this part of the list may be new to you.
But don’t worry, I am just listing out several examples so that you are aware of the name, that’s it.
So, what did you understand?
Most of the programmable hardware were built on C based software code and they continue to be written in C language even in the year 2025 and beyond where AI is said to be the software engineer replacer.
Did you see, most of the Operating Systems are written in C, all the device drivers are written in C, almost all databases are written in C, world’s fastest Server software is written in C language and many more.
This is just the beginning.
Hold your breathe to understand more on the the importance of C language so that you would be confident against the dominance of AI now and even in the future.
How C Programming is Used in the Underlying AI Infrastructure?
Now that you know how widely C programming is used, let’s take a look what is at the core of the infrastructure on which AI is running.
For the general public AI may seem like to write some prompts and the AI model responds just like a human responds.
Well, this is just the front end user interaction. But on the contrary, there is much more behind just prompting and getting a response.
I am not going to explain in detail about the how each layer fits in the AI infra, but I will just try to give you a perspective on how different hardware or software components on the infrastructure are relying on C programming.
Hardware Involved in AI model and User Interaction
Let’s take a look at the hardware components involved between the user and AI model in the backend:
- Phone, Laptop, PC, Macbook, Tablet, etc. (The user may use one of these)
- All these devices have subcomponenets such as: Flash / HDD / SSD storage, display, wifi controller, Modem etc.
- The software that runs on all these above hardware are built using C language.
- Wifi or Internet connection
- The hardware that makes it possible to access the user to reach the AI agent has firmware inside that is built on C language
- ISP or Network Routers
- The data from the user to the server reaches via ISP which consists of many more systems or routers. These systems or the routers run on software out of which majority is again written in C language.
- Server Hardware on which the AI model runs
- Typically these are very high end servers which are hosted in datacenters
- The whole server infra consists of Server machine which has datacenter grade processors, Hard disk or SSDs, Network switches to route the request or response traffic, High end GPU to process the request and may use individual storage to host Database
- All these hardware components are running on some software, firmware or device driver which are majorly built using C language.
I have briefly listed several components which are involved starting from the user till where the AI model is hosted.
Now let’s look at the software components involved in the whole process.
Software Involved in the AI and User Interaction
More or less the above hardware is used to take a query from the user, process the request and send back the respond to the user.
I want to emphasize that the whole process requires several software components which are built using C language. My point here is only to showcase how much the whole infrastructure is built on C language; which does not mean no other language is used at all.
Once you understand this point, let’s take a look at the software parts which are built on C language:
- Operating system software (that runs on Phone, Tablet or PC / Mac)
- Server Software (AI websites such as openai.com or perplexity.ai are hosted either on Apache or Nginx server software which are written in C language)
- Database software (SQLite, MySQL, OracleDB etc.)
- Network software (Datacenter is powered by L2 / L3 switches built by Cisco, Arista, Juniper (HPE), have their own Operating System which are heavily built using C language)
Here again, I have mentioned very high level software components which are involved from a user frontend and the backend of the AI model.
Dependency of AI on C Programming
I am not talking about how the AI models are built. But AI models essentially need the basic infrastructure to run such as: Server hardware, GPU, Network switches, Server software, Database software, etc.
To be able to access an AI model from the user’s end or to host it on the backend, it needs a lot of hardware or software resources which are directly built using C language.
This makes the AI indirectly dependent on things which are actually built using C language.
These infrastructures were already there even before AI was evolved where it is today. It is not possible to replace those all anytime soon.
AI may be used to fast track or automate some of the process but it is not going to replace any existing working infrastructure.
Why C Language is Not Replaced in 50+ years?
A processor or a controller is the heart of any programmable system.
As I have explained in one of the previous section that the processor understands only machine language or instruction set.
Complete Feature Set
C language was the only high level language which provided all necessary features to access a complete system.
It provided ways to allocate memory for a process, allowed access to deal with hardware registers, provided libraries to deal with text or string and many other wide range of data types.
Over the period of time, where the industry felt to add some more features to it, rather than working on an entirely new programming language, the C language was improved with new standards such as: ANSI C, C99, C11 etc.
Performance and Efficiency
When a C program is compiled, it is directly converted to the process understandable machine instructions.
Basically, you can think like, a software made out of C program, directly runs on the hardware or the processor. There is no intermediate layer or overhead.
This means, the software made out of C program is very fast and runs efficiently on the hardware without adding any extra layer of processing.
Because of this performance and efficiency aspect, software such as Apache, Nginx, SQLite, OracleDB etc. are built using C language.
For example, to run a python script, PHP or Java code, you need to run them via their runtime environment (bytecode or some machine independent code) and then these runtime convert the intermediate code to machine understandable instruction set.
You see, this extra step involved in other languages make it slower and less efficient.
Legacy and Support
50+ years in the industry itself has made the C language much stronger.
C, is easy to understand and directly runs on hardware, this is why almost every hardware vendor has used it in their project. This is where you see most of the device drivers are written in C language.
The Linux Kernel has 90%+ code written in C language which powers most of today’s datacenter machines. Not just Linux, FreeBSD, Windows OS, Mac OS etc. all their kernel is written in C language.
Most of the embedded devices are written on C based code which directly runs with the hardware.
Because of this proven track record the C language, it has gained a great community support from developers across the world and eventually a legacy has been built which is pretty hard to change over the night or even in few years.
Why I am Confident C Language is Irreplaceable Even after AI?
I have already answered this little by little in all previous sections. Finally I am consolidating everything here to make you feel more comfortable about C language in the era of AI dominance.
As I have said, C language is one of the rare high level language that is easy to understand for the humans, and it directly runs on the processor when compiled, without adding an extra layer of overhead for execution.
A lot of places where performance is a must such as: Server software, Database software, Network hardware (Ethernet, Wifi, Bluetooth etc.) etc. it is important to use software which can harness the capability of the hardware in realtime.
C language is the answer for the above.
To the frontend it looks like any other language, but when compiled it completely converts into machine language, without adding any hidden overhead to the hardware.
It has been in the industry for more than 50+ obvious years and it ill continue to be there because of its performance, user friendliness, strong developer support, strong legacy and last but not the least, its own capabilities.
Instead of creating a new high level language for the hardware, C language has been improved to be capable to handle all modern hardware.
I have been in the industry for more than 15 years and worked on several huge companies and I only worked on C language. Of course, understanding Data Structure and Algorithms are equally important to write production level code.
Even if AI is here, the underlying hardware and software that makes AI possible are all based on C code.
Be it the Operating System, the phone, PC or Mac, the server hardware, the GPU, the network switches, the databases all runs on software which are built using C language.
Conclusion
I can understand how overwhelming it is for you as a student to think beyond AI where everyone is creating a hype that AI will replace everything.
Certainly that’s not true. AI is a platform which makes human life easy by adding extra layer of help in certain area of life. Of course it is useful and it will take you ahead if you use it smartly.
But one important thing to remember is that AI is here to help us humans and not to replace.
Majority of my explanation for C language was with respect to AI, hence I have covered examples of Datacenter, servers etc.
A lot of house hold things which are consumed at scale such as: Washing machine, TV, Camera (any kind of camera: IP camera, handheld camera, dashcam for car), Water purifier, Phones, computer, wifi routers, etc. everywhere C language is used.
I am not saying only C language is used, rather where you see a programmable hardware, that certainly uses C language.
I have made my career out of C language and I have been in the industry for more than 15 years and I am sure I will remain relevant with my C language skill in the future.
Before closing, I want to add that not just C, I have few other understandings which keeps me skillful and this confident. Below are my expertise:
- Very good hold on C language
- Very good understanding of Data Structures and Algorithms
- Good understanding of Linux System Level programming (using fork, semaphores, shared memory, IPC, threads, etc.)
- Good understanding of Linux Device Drivers
- Very good understanding of overall system hardware and design
I have listed all my skillset in brief because before you leave from here I want you to look at overall skill development is necessary to create a very robust career and not just think that learning C language is enough.