There's no such thing as "Full" anymore
We've done a disservice to the term "FullStack." But worse than that, we've been lying to ourselves.
At some point, it got flattened into "web dev who can do frontend and backend." That's how it shows up in job descriptions, job titles and Linked job posts. But the truth is, there's no such thing as "Full Stack" anymore. There never really was, and the AI revolution has just made that impossible to ignore.
It's time to call it what it actually is: MultiStack.
This post builds on ideas from Zac Sweers' "Forklifts Require Training" - essential reading on how AI pressure is affecting junior developer learning and the tech industry as a whole.
Because here's what "FullStack" should really mean:
Can you build something people actually use? Can you carry a product from zero to something in a user's hands, and keep it working when it breaks? Can you navigate multiple stacks - web, mobile, AI, infrastructure - without claiming mastery of everything?
That's MultiStack.
Sometimes that's a web app. Sometimes it's mobile only. Sometimes it's embedded software running in the middle of nowhere. Sometimes it's an AI-powered CLI tool. You don't have to know every stack detail, but you can work effectively across multiple stacks and know when to dive deep vs when to stay surface-level.
It's about breadth with selective depth. And it's heavy.
Before you start debating what "FullStack" should or shouldn't mean - that's not the point of this post. The point is that the term has become so diluted and overloaded that it's actively confusing people entering our industry.
AI Made "FullStack" Impossible
Just look at what we're calling a "modern software stack" in 2025:
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Nine different layers. Each with multiple competing technologies. And this doesn't even include the LLM stack on each layer where everything must have RAG based app integration.
In the last year, things have gotten completely out of hand. We're telling junior developers that FullStack now includes:
- LLM architecture and prompt injection defense
- Embedding generation and retrieval pipelines
- Prompt evaluation
- PyTorch and custom fine-tuning
- Multi-agent frameworks and serverless orchestrators
I've seen this happening still now with all the interviews I had since I opened to the market last Aug 1.
That's not a stack anymore - that's an entire technology ecosystem. The term "FullStack" has become meaningless because nothing will ever be "full" in the AI revolution. The stack keeps growing faster than any human can learn it.
MultiStack is honest about what we're actually doing: working effectively across multiple, ever-changing technology stacks while being selective about where we develop deep expertise.
And when they ask "how do I learn this," the answers are:
- Some YouTube videos
- Blogs with half-working code
- An open-source repo that only works on one person's machine
- Maybe a paid course.
All while hiring freezes and layoffs make it feel like getting a junior role is like winning the lottery.
Production Is the Best Teacher
The hardest lessons I've learned didn't come from a tutorial or blog. They came from being on call when things broke.
- When millions of users couldn't connect because I pushed a bad config
- When a randomness failure in our session management caused network conflicts that crashed a core telco infrastructure.
- When data didn't sync and someone's business lost millions of earnings.
- When the mobile app's retry logic during development racked up thousandsof USD in infra costs before anyone noticed.
- When you accidentally deleted the whole S3 bucket of images because you thought it was unused. WITHOUT BACKUP...
Those moments are what actually teach you how systems behave under pressure. They teach you what good and bad look like. What brittle looks like. What slow looks like. What you'd never do again. You stop memorizing design patterns and start developing taste.
And this is exactly where experienced engineers have a massive advantage in the AI boom. You've seen how production breaks. You've seen how infra gets tangled. You've seen what's hard to test and even harder to roll back. That lens is incredibly valuable now.
Real engineering wisdom comes with scars. The kind you get from watching your code fail in production at the worst possible moment.
What Are We Training For?
Here's the question no one seems to want to ask:
Should we be training junior engineers across multiple stacks?
Should we be handing them the keys to the web stack, mobile stack, infra stack, and now the AI stack, and expecting them to keep up?
Or are we just throwing them at the deep end and hoping they swim?
There's this lingering idea that "anyone can code" and that programming is now easy. It's not. Not when real users are on the line. Not when revenue depends on it. Not when the AI model starts hallucinating medical advice and someone has to own that liability.
You don't learn how to be a MultiStack engineer by watching videos. You learn by building things that break and fixing them. You learn by carrying a system long enough to regret your early choices. You learn by having users rely on you. And then you learn by mentoring the next person through the same fire.
That's the real MultiStack. And it doesn't fit in a bootcamp.
Final Thought
MultiStack isn't frontend plus backend plus AI plus mobile plus DevOps. It's product ownership across multiple technology domains.
It's knowing the difference between a cool prototype and a reliable system. It's knowing when not to ship. It's knowing what failure smells like before the dashboard lights up red. It's knowing which stack to use when, and when to learn new ones.
That's the kind of engineer you want on your team.
And if you're a new grad reading this, don't try to master every stack. Focus on building something someone uses and that someone can be you as the first user. Then make it better. Then make it resilient. Then learn the next stack you actually need.
That's how you become MultiStack.
Top comments (3)
well said.
I like this idea too. an Engineer is really a great term to capture the person doing it!