
Half a Percent of Your Codebase, 100% of the Magic
Let me ask you something. Have you been seeing all this excited advice about rebuilding everything with AI at the center? AI-first applications. AI-native workflows. The whole nine yards.
Most custom software development projects being built right now aren’t AI software at all. They’re regular code solving regular problems. They’re replacing the Excel macro that’s held together with prayers and hope. We’re building the tool that doesn’t exist because no SaaS vendor cares about your specific edge case. Same projects companies have needed forever.
What’s different – and this is where it gets interesting – there’s almost always one spot where you drop in AI and the whole thing transforms.
We call it the magic Lego brick.
What Makes Custom Software Feel Magical Without Being an AI Application?
Rob built an app with 40,000 lines of code recently. Less than 1% of it touches a large language model.
When clients use it, it feels like talking to someone impossibly wise who knows everything about their business. The traditional code disappears. What’s left feels alive.
If you put it on a scale, the LLM usage is like half a percent of its weight. And yet the user experience of interacting with it is completely the opposite.
That gap matters. A lot.
We’re not building AI applications. We’re building applications that happen to have AI in exactly the right spot. One or two places where it does something regular code can’t touch.
The rest? Just code being code.

How Do You Place AI in Custom Software Development to Maximize Impact?
Justin Mannhardt on our team is building a personal productivity app right now. Most of the work is traditional infrastructure – data handling, user interfaces, all the scaffolding that makes software function.
Then there are specific points where he wants an LLM involved. Not for show. Because it solves a problem regular code is terrible at.
When we’re doing custom software development work, 99% of our time goes to the parts that route information, store data, handle permissions, manage state. The boring infrastructure work that’s been the same for decades.
That last 1% is where you drop in the piece that makes users forget they’re using software.
Strategic AI placement isn’t about sprinkling LLMs everywhere like fairy dust. It’s about finding the one or two spots where AI solves something traditional code can’t handle.
Where Should You Look for the Magic Lego Brick in Business Workflows?
Once you start looking, you find them everywhere.
Almost every business workflow has at least one point where someone needs to interpret something, make a judgment call, or translate between contexts. That’s where AI fits.
Customer service workflows have a spot where someone needs to understand what a frustrated customer means versus what they literally said. Magic Lego brick.
Data entry processes have a spot where you need to take messy, inconsistent input and figure out what it maps to in your clean system. Magic Lego brick.
Approval workflows have a spot where someone needs to summarize why this request matters and what the context is. Magic Lego brick.
We’re seeing this pattern consistently. Most of the workflow is structured, predictable, handles nicely with traditional code. But there’s always a spot where you need something that deals with ambiguity, context, and human messiness.
That’s your spot.

Why Strategic AI Placement Beats Building Everything AI-Native
Because we’re trying to solve specific problems, not win innovation awards.
Custom software development has always been about understanding what people need, then building the simplest thing that delivers it. AI doesn’t change that fundamental reality. It just gives us a new tool for the parts that used to be impossible.
The incremental lift to add a magic Lego brick isn’t massive once you know where it goes. You’re not rewriting your entire application. You’re identifying one or two points where an LLM adds something regular code can’t provide.
Then you drop it in.
The result feels disproportionately magical. Half a percent of your codebase creates 100% of the “this feels alive” experience.
Pretty cool stuff.
How AI Tools Are Changing Custom Software Development Speed
Here’s something that’s easy to miss – you’re probably building both AI-assisted and AI-powered software without realizing it.
AI tools like Claude and GitHub Copilot help us write the code faster. We’re building traditional applications at speeds that weren’t possible two years ago.
Then we find spots to put AI inside the code itself. Not because we planned an AI project. Because once we’re building, we see where it fits.
The custom software that replaces your VBA workflows or your overpriced SaaS tools won’t be marketed as AI solutions. They’ll just be better. Faster to build. More intuitive to use. More flexible when your needs change.
What to Look for in Your Next Custom Software Development Project
Look for the spots where people are currently doing interpretation, translation, or judgment work that feels repetitive but requires context. That’s where AI belongs.
Build everything else the normal way.
We’re having these conversations with clients right now – where does AI belong in their operations versus where regular code does the job just fine. The answer is almost never “everywhere” and almost never “nowhere.”
It’s usually one or two very specific spots that transform the whole experience.
If you’re trying to figure out where those spots are in your workflows, schedule a call.
Get in touch with a P3 team member