Synchronicity vs. Asynchronicity: The Art of Building FinTech That Works

The FinTech Speed Dilemma

One of the biggest challenges in FinTech is speed. Everyone wants transactions to be instant, systems to be seamless, and processes to be handled in real-time. But here’s the real question—should everything happen instantly?

Think about it: if we applied the same logic to our daily lives, we’d expect one person to work a full-time job, design their own clothes, wash them manually, cook all meals, and personally deliver their own products. Sounds ridiculous, right? Yet, we somehow believe that one system should do everything, immediately, without delay.

The reality? FinTech systems are like us—they thrive when tasks are distributed effectively.

White dominos ready to set off a chain reaction, illustrating asynchronicity in motion.

The Misconception of Doing It All

When designing financial systems, the key to speed isn’t making one process do everything—it’s knowing how to divide responsibilities. In our daily lives, we delegate:

• We buy clothes instead of making them

• We use washing machines instead of scrubbing by hand

• We order food when we don’t have time to cook

Technology should be no different. It’s not about making everything instantaneous—it’s about making sure the right processes happen at the right time.

Synchronicity vs. Asynchronicity: The FinTech Perspective

Now, let’s take this to financial transactions. What really matters to the end user when they make a purchase?

• Seeing the transaction instantly: Yes, they need to know their amount spent and updated balance. That should be synchronous, meaning it happens immediately.

• Processing additional operations like fees, rewards, or cashback: No, this doesn’t need to happen instantly. These tasks can be asynchronous, meaning they process in the background without affecting the user’s immediate experience.

Why? Because trying to make everything happen at once slows everything down. It’s like asking the clothing store assistant to deliver your food while processing your order—it’s not their job.

Building Smarter FinTech Architectures

To create scalable, efficient, and user-friendly FinTech solutions, we must:

• Prioritize synchronous operations only for tasks that directly impact the user experience in real-time (e.g., balance updates).

• Use asynchronous processing for tasks that can be completed later without disrupting the transaction flow(e.g., applying rewards, calculating fees).

• Distribute responsibilities effectively across microservices, ensuring that each component of the system does what it’s best at—instead of forcing everything through a single process.

The Bigger Picture: We Are Not Built to Do It All

At the end of the day, technology mirrors life. Just like humans, systems aren’t meant to do everything at once—they are part of a larger ecosystem.

Understanding when to use synchronicity vs. asynchronicity is not just an engineering decision—it’s an architectural mindset that defines scalability, efficiency, and user experience.

Because in FinTech, just like in life, the best systems are the ones that know how to delegate.