The Cost of Speed - Boundary Blog

We've all heard it: "Move fast and break things." It's become a mantra of modern software development, a badge of honor for teams that ship quickly. But here's what they don't tell you: some things, once broken, stay broken for a very long time.

I want to talk about the decisions that compound. The ones that seem fine in the moment, maybe even necessary, but become anchors that drag your team down for months or years. These aren't bugs you can fix in a sprint. These are foundational choices that shape everything that comes after.

The Database Schema That Couldn't Scale

A few years ago, I worked on a project where we needed to store user preferences. The requirement seemed simple: users could customize their dashboard. We had a deadline, so we made a quick decision: store everything as JSON in a single column.

It worked. We shipped on time. The feature was great.

Six months later, we needed to query those preferences. "Show me all users who prefer dark mode." Can't do it: it's JSON. We needed analytics: "What percentage of users customize their dashboard?" Can't tell: it's JSON. We needed to migrate data: "Move preferences to a new system." Can't do it cleanly: it's JSON.

What seemed like a time-saver became a blocker. Every new feature that needed to interact with preferences required workarounds. We built query systems on top of JSON. We created migration scripts that parsed and transformed. We spent engineering time on problems that wouldn't exist if we'd taken two days to design a proper schema.

That "quick" decision cost us months of engineering time over the next two years. And we're still living with it.

The API Contract That Broke Everything

Another team I know built an API for a mobile app. They needed to ship fast, so they made everything flexible: optional fields, loose validation, versioning handled through feature flags. "We'll clean it up later," they said.

Later never came.

The mobile app shipped. It worked. Users loved it. But then they needed to build a web app that used the same API. The loose validation meant the web app had to handle edge cases the mobile app never encountered. The optional fields meant the web app had to guess what data was actually present. The feature flags meant the web app had to support multiple versions of the same endpoint.

They tried to fix it. They added validation. They made fields required. They deprecated old versions. But the mobile app was already in production, with thousands of users. Every change risked breaking the app. Every improvement required careful migration. Every new feature had to work with the old, messy contract.

What should have been a two-week project to add a web app became a three-month project of working around the API's flexibility. The "quick" decision to be flexible became a constraint that limited everything they built afterward.

The Architecture Choice That Seemed Right

I've seen teams choose microservices because it was the "modern" approach. They split their monolith quickly, creating services for each major feature. It worked. They shipped faster, initially.

But then they needed to add a feature that touched multiple services. What should have been a simple change required coordinating deployments across three services. They needed to debug an issue that spanned services. What should have been a quick investigation required tracing requests through multiple systems.

The "quick" decision to adopt microservices created operational complexity that slowed them down for years. They spent more time on deployment coordination, service communication, and distributed debugging than they saved by splitting the monolith.

Why Speed Creates Debt

Here's what's happening: when you move fast, you make decisions with incomplete information. You optimize for the immediate problem, not the problems you'll face later. You choose the path that gets you to "done" fastest, not the path that makes future work easier.

This isn't necessarily wrong. Sometimes speed is the right choice. But some decisions are irreversible, or at least expensive to reverse. And those are the decisions where speed creates debt that compounds.

Decisions That Compound

Some decisions compound because they become the foundation for everything else:

Database schemas: Once you have data, changing the schema is expensive. Migrations are risky. You can't just refactor.
API contracts: Once clients depend on your API, changing it breaks things. You can version, but that creates complexity.
Architecture choices: Once you've built on a foundation, changing it means rebuilding. The cost grows with every feature.
Data models: Once you've stored data in a format, changing it requires migration. The more data, the harder it gets.

These aren't decisions you can "fix later." They're decisions that shape everything that comes after.

The Invisible Cost

The cost of speed is often invisible. You don't see it in the moment. You see it later, when:

A simple feature takes weeks because of a foundational decision
You spend engineering time on workarounds instead of new features
You can't move forward because of constraints you created earlier
Your team burns out cleaning up messes they didn't create

The person who made the quick decision has often moved on. But the team lives with the consequences.

When Speed Is the Right Choice

I'm not saying you should never move fast. Sometimes speed is exactly what you need:

Experiments: When you're testing an idea, speed matters. You want to learn quickly, even if it means throwing away code.
Temporary solutions: When you know something is temporary, speed is fine. You'll replace it soon.
Low-stakes decisions: When a decision doesn't affect much, speed is fine. You can change it later without much cost.

But when a decision will affect everything that comes after, speed is the wrong optimization.

How to Know When to Slow Down

The question isn't "should we move fast?" The question is "will this decision compound?"

Ask yourself:

Will this affect future work? If this decision becomes the foundation for other features, it will compound.
Is this hard to change? If reversing this decision is expensive or risky, it will compound.
Do others depend on this? If other systems, teams, or users depend on this decision, it will compound.
Does this create constraints? If this decision limits what you can do later, it will compound.

If the answer to any of these is "yes," slow down. Take the time to think it through. The cost of slowing down now is much less than the cost of living with a bad decision later.

The Permission to Slow Down

Here's what I've learned: the best engineers aren't the ones who move fastest. They're the ones who know when to slow down.

They've seen the cost of speed. They've cleaned up messes created by quick decisions. They know that some decisions are worth taking time to get right.

But our culture doesn't always support this. Slowing down can feel like failure. Taking time to think can seem like procrastination. Being careful can look like you're not moving fast enough.

We need to change that. We need to give engineers permission to slow down when it matters. We need to recognize that thoughtful decisions are professional, not a failure of speed.

The Tool for Decisions That Compound

This is why we built Boundary. It improves the quality and richness of decisions through on-demand AI agent debates with diverse mindsets. It doesn't make you faster. It makes you better, by giving you multiple perspectives when you need them.

Boundary exists for the decisions that will hurt later if you get them wrong now. It's for the database schemas, API contracts, architecture choices, and data models that will compound over time.

It's not exciting. It's not about moving fast. It's about making decisions you won't regret.

Because the cost of speed isn't always worth it. Sometimes, the best thing you can do is slow down.

Boundary improves the quality and richness of engineering decisions through on-demand AI agent debates with diverse mindsets. Try Boundary for your next critical decision.