In August 2026, I joined an AI hackathon for the first time.
Two words I saw there for the very first time really stuck with me: “frontend” and “backend.”
Wait, what are those?
Around lunchtime on the day of the hackathon, someone shared a slide where participants could introduce themselves and look for teammates. There was a space to write your job or what you were good at.
I saw things like “Backend developer” and “I mostly work on the backend, and frontend isn't really my strong suit.”
There were plenty of other unfamiliar job titles, too. Some kind of director, this kind of specialist... I at least knew what an SE (systems engineer) was! (Haha.)
Apparently, these are everyday words in the world of AI and app development.
But they were completely new to me!
Fast-forward about two months.
I was now taking part in an international AI hackathon with a Vietnamese AI engineer. Just the two of us on one team.
And in the Idea Proposal my teammate prepared, guess what he listed as my role?
Frontend.
Hold on a second.
Two months ago, I didn't even know what that word meant! (Haha.)
So here's my attempt to explain frontend and backend through the experiences I've had as a non-engineer at AI hackathons.
My First AI Hackathon—and a Whole New Vocabulary
My first event was AIAU Craft Day, in August 2026.
I was interested in building things with AI, but I'd never worked as an engineer.
Still, I had already been using AI to help me build apps of my own, so I decided to give the hackathon a try.
Once I got there, I kept coming across technical terms I'd never heard before.
Frontend and backend were two of them.
At first, I didn't really understand the difference.
But at a hackathon, a team is trying to build something together. That means figuring out who will take care of which parts.
Little by little, I started to see why these two terms mattered.
So, What's Frontend?
Put simply, the frontend is the part users can see and interact with directly.
Think of what you see when you open a web app.
Buttons, text boxes, menus, words, images—all those things.
“Click here to open the next screen.”
“Type something here and see it appear on the screen.”
Building the part that connects the user to the app is frontend work.
But there's one important distinction.
Frontend and design aren't the same thing.
Choosing colors, fonts, and screen layouts is part of UI design.
Turning those designs into actual screens that work in a browser also requires programming.
So deciding how something should look and making it actually work are related—but they're not necessarily the same job.
Then What's Backend?
The backend is the part that handles processes behind the screen.
For example, imagine searching for something in an app.
The screen where you type a search term, press a button, and see the results is part of the frontend.
Meanwhile, receiving that search term, finding the relevant information, and sending the results back may happen on the backend.
Retrieving information from a database, saving data, or communicating with other services are often backend tasks, too.
Of course, the exact division depends on how an app is built.
But as a beginner, this was an easy way for me to picture it:
Frontend = the part users interact with.
Backend = the part that handles things behind the scenes.
A Familiar Example: Booking a Restaurant Online
Imagine making a restaurant reservation online.
On your phone, you choose a restaurant, enter the date, time, and number of people, and tap “Book.”
The screen you're looking at and interacting with is the frontend.
So what's the backend doing?
After you tap the reservation button, the system might check whether a table is available at that time and save your reservation details.
Then it sends back a result to tell you whether your booking went through.
Those behind-the-scenes processes are backend work.
The details vary from service to service, of course, but this example makes the difference easier to understand.
One part lets you interact with the screen. The other handles the processing behind it.
Even services we use without a second thought rely on their frontend and backend working together!
Huh. I'd never thought about any of that while booking a restaurant! (Haha.)
And Then I Was Listed as the Frontend Person at an International AI Hackathon!
In October 2026, I joined Vietnam Japan AI Hackathon 2026.
I teamed up with a Vietnamese AI engineer to create FrostLoop AI, an AI Agent for Amazon sellers.
I shared CSV files from my actual Amazon business, and my teammate showed me that he'd built much of the Agent in about three hours.
He handled most of the technical implementation.
I contributed my experience as an Amazon seller and my ideas from the business side.
And there was one more thing.
I told him I wanted to work on the screen's colors, fonts, and UI design.
Later, I saw that he'd written “frontend” as my role in our Idea Proposal.
Oh, wow! That's really kind of him. I could only take care of a small part of it, but he'd still given me that role.
A word I first learned at my very first hackathon was now part of my own role!
I found that pretty funny—and kind of amazing.
But I Can't Build the Entire Frontend
I want to be clear about one thing.
Just because the proposal listed me as the frontend person doesn't mean I could program the entire frontend by myself.
I'm still learning how to collaborate on projects through GitHub, too.
Here are some of the things I was actually working on:
- Creating an image for the project's logo
- Making an animated version of the logo
- Choosing colors that worked with the logo
- Suggesting ideas for the UI's appearance and layout
- Creating images to use on the screen
- Making a character and short video clips
- Creating popup images that could appear when someone takes an action
But that's only a small part of what frontend work involves.
Frontend work can also mean writing the code that builds the screens, making buttons respond when clicked, and displaying data received from the backend.
It can involve making sure the layout works on both phones and computers, making an app easier for everyone to use—including people navigating by keyboard—and testing how the screens look and behave.
What I've mainly been involved with is the visual side: colors, fonts, layouts, screen composition, images, and animations.
Getting those assets into the actual app and making them respond to user actions takes further programming. Creating an image and implementing it as a working feature are two different things.
So even though I was listed as working on the frontend, what I could do was still just a small piece of it.
But when you're working as a team, you don't have to do everything yourself, right?
You can contribute where you're able and work with people who are better at the other parts.
I realized that's one way to take part, too.
I sell products under my own brand on Amazon, and I've always created the visual designs myself—logos, product images, packaging, and so on.
Maybe that branding experience could come in handy here as well.
You don't have to understand every technical detail to bring something useful to a team.
That reminds me of a conversation I once had with a web designer.
I'd assumed that being a “web designer” meant building an entire website. But as we talked, I learned that this person didn't handle coding. They mainly created image assets.
It was quite different from what I'd imagined, but it taught me that people with the same job title can have very different responsibilities.
Maybe being called a “frontend” team member is a little like that.
Can AI Help Non-Engineers Take On More?
This is another thing I've been finding fascinating lately.
In the past, I think building a web app's screens would have been pretty difficult for someone with very little programming experience.
But now, with tools like Claude Code and Codex, you can ask AI for help writing and editing code.
Of course, just because AI writes code for you doesn't mean you can skip checking it.
Does the screen work as intended? Did a change break something else? Which parts are you actually supposed to modify?
Those are still things you need to understand.
Even so, I feel like it's easier than before to give it a try.
I'm still learning myself.
But I've stopped thinking that being a beginner means there's nothing I can do.
Two Months Earlier, I Didn't Even Know the Words
Looking back, it's a little strange.
At my first hackathon in August, I encountered “frontend” and “backend” for the first time.
By October, my teammate had included me in a frontend-related role in the Idea Proposal for an international AI hackathon.
Of course, I didn't become an engineer in two months! (Haha.)
There's still so much I don't know.
But by showing up, seeing unfamiliar terms, looking things up, and trying new things, I've gradually found more that I can do.
You don't have to understand everything before you join. Sometimes, joining is how you begin to understand.
Maybe that's one of the things I love about AI hackathons.
I'm sure I'll run into more unfamiliar words at my next hackathon.
And I'm looking forward to it!