Escaping the Horizontal Trap: Why Vertical Slicing is the Secret to Smoother Software Development

Have you ever felt like your software project is a runaway train, barreling forward with no stops, piling on complexity, and leaving your team exhausted and frustrated? If so, you might be stuck in the horizontal trap. In my career guiding teams in software development, I’ve seen this pattern repeatedly: the more a team struggles with project management, the more their backlog is clogged with horizontally sliced stories. But there’s a way out, a shift to vertical slicing that can transform frustration into momentum and deliver real value, fast.

The Recipe for Chaos: Horizontal Slicing

Picture this: you’re tasked with building a recipe website. You sit down to plan, and the instinct kicks in; let’s break it down logically. A horizontal approach might define a single story: “Build the recipe page,” complete with ingredients, cooking steps, nutritional info, images, and user comments. Sounds straightforward, right? But here’s the catch: that one story balloons into a monster. Suddenly, you’re juggling a dozen interconnected features, each sprawling across multiple pages like the nutrition calculator, search, and recipe display. Before you know it, you’re drowning in complexity.

Why does this happen? Horizontal slicing (dividing work by broad layers like “frontend,” “backend,” or entire user flows, e.g., “front page,” “search page,” “recipe page”) creates a web of dependencies. The recipe page needs nutritional data, an ingredients structure, backend logic, etc. It’s a negative feedback loop: every task blocks another, stalling progress and sapping team morale. I’ve watched teams grind to a halt under this weight, momentum lost to endless debates about what’s “done.”

A Better Way: Vertical Slicing

Now, could you imagine a different approach? Instead of tackling the entire recipe page at once, you start small: an introductory page that displays the recipe title and description. Done. Next, you add ingredients. Then cooking steps. Then, there are images, nutritional info, and user comments, each as its vertical slice. Every step delivers something tangible, something users can see and interact with.

Vertical slicing forces you to think in terms of value. Each slice is a complete, functional piece of the product, no half-baked layers or abstract tech components. This keeps tasks manageable, reduces dependencies, and lets you refine iteratively. For that recipe website, you’re not just coding; you’re shipping a usable feature with every sprint. Developers see results, stakeholders give feedback, and the project hums along.

The Horizontal Trap: A Sneaky Culprit

So why do we fall into horizontal slicing? It often starts with good intentions. “Let’s follow the user’s journey!” you say. You map it out: the user lands on the front page, searches for a recipe, then views it. Boom, three epics: front page, search page, recipe page. Or maybe you’re a classic developer: “It’s a website, so we need database, backend, frontend, and a mobile app.” Four epics, ready to roll. But here’s the trap: these broad slices sound neat, but they’re a nightmare to execute.

I’ve seen this play out too often. You’re meeting with a business owner, sketching out their grand vision. Time’s tight, details are fuzzy, and you default to the most straightforward breakdown: big, horizontal chunks. Suddenly, you’ve got epics that can’t be tackled independently. Each one demands most of the project’s complexity upfront, creating circular dependencies that choke progress. Teams end up paralyzed, unable to deliver anything usable until everything’s “done.”

Breaking Free: The Power of Vertical Thinking

The antidote? Stop dividing work by technology or design alone. A feature isn’t just “frontend” or “backend,” but a blend of both, delivering value together. For that recipe website, don’t build the entire frontend first; build a slice like “display basic recipe” that cuts through all layers (UI, logic, data) in one go. This shift simplifies development, boosts team morale, and keeps the focus on what matters: the user.

As teams gain experience, they naturally drift toward vertical slicing. It’s intuitive; delivering small wins feels better than slogging through sprawling epics. But even seasoned teams can slip back into the horizontal trap if they’re not vigilant. Awareness is key: catch yourself when slicing by layers instead of value.

A Timeless Debate: Code Meets Stories

This isn’t just about project planning; it echoes a decades-long debate in software development about splitting code. Horizontal splitting divides components by function (e.g., separate modules for UI, logic, data), while vertical splitting integrates them into feature-rich units. Sound familiar? It’s the same principle, mirrored in how we organize stories. The Single Responsibility Principle (SRP) fuels this discussion, but modern tools like TailwindCSS and component-centric frameworks are tipping the scales toward vertical thinking. For a deep dive, check out Pete Hunt’s talk on Horizontal vs. Vertical Splitting; it’s a goldmine.

Rethinking Your Backlog with Vertical Slicing

To break free from the frustration of slow progress, start by reimagining your backlog. The key question is: “What’s the smallest functionality that delivers value to the user?” For your recipe website example, it’s not about “building the recipe page” as a broad task. Instead, focus on something specific and immediately usable, like “display a single recipe with its title, ingredients, and steps.” This is vertical slicing: crafting standalone stories that deliver tangible value immediately, rather than splitting work into technical layers like “frontend” or “database” that users can’t experience until everything is stitched together.

A New Analogy: Hosting a Dinner Party

Imagine you’re hosting a dinner party. Instead of preparing the entire meal of appetizers, main course, and dessert and serving it only when everything’s ready, you bring out one complete dish at a time. Start with a simple appetizer, like a plate of bruschetta. Your guests can enjoy it immediately while you work on the next dish, a pasta course. Each dish is fully prepared, served, and appreciated independently, contributing to the overall dining experience. You don’t wait to serve until the dessert is plated, your guests would be starving!

This mirrors vertical slicing in software:

Incremental Value: Each “dish” (or feature) is complete and enjoyable, like first showing a recipe title and ingredients.

Cross-Functional Effort: Preparing a dish involves multiple steps, such as chopping, cooking, and plating, just as a software slice requires UI, logic, and data to work together.

Immediate Usability: Guests (users) can savor each course as it’s served, giving you feedback to tweak the next one, rather than waiting for the whole meal.

Why This Matters for Your Recipe Website

Instead of tackling the entire recipe page in one go, slice it vertically:

Slice 1: Display a recipe’s title and description. Users can browse recipe names and see what’s cooking.

Slice 2: Add ingredients to the display. Now users can check if they have what’s needed.

Slice 3: Include preparation steps. Users can start cooking with a complete recipe.

Each slice stands alone, delivers value, and cuts through all layers, frontend, backend, and data, avoiding tech-only splits that delay usability.

How to Apply This

Prioritize User Value: Focus on what users can see and use, not just what you're building behind the scenes.

Keep Slices Thin: Break tasks into small, complete units that span all necessary components.

Test Independence: If a slice can’t ship without another piece, it’s not vertical, rethink it.

By slicing your backlog this way, you’ll deliver working features faster, keep users engaged, and avoid the trap of incomplete, layer-by-layer progress. It’s like serving a delightful dinner one dish at a time, everyone’s happy sooner, and you’re free to refine the menu as you go!