9 characteristics of a great custom software solution

10 min read
June 16, 2023

Not all custom software is made the same.

Take London’s (now failed) ambulance dispatch system that was introduced in 1992.

What was supposed to be a solution that could reduce emergency response times significantly instead slowed them down and caused between 30 and 45 deaths.

And the simple reason is that the system couldn’t handle all the incoming requests. It wasn’t scalable.

Scalability is just one of the critical factors that any great custom software solution must possess.

We’ll talk about nine of them in this article.


Functionality is the fundamental quality that every custom software should have.

It means that the custom software has specific features that function exactly as the client intended in order to tackle needs or solve problems.

If custom software can’t meet this basic requirement, then it really shouldn’t be called custom at all!

But to be functional, it’s not enough for software to have the right features. It must also fulfill certain performance requirements that are critical to a situation.

For instance, say you have camera security software that needs to transmit camera footage in real time.

If there’s a noticeable lag, the software isn’t usable because it can’t fulfill its basic purpose.

To make functional custom software, it’s best to follow the software requirements specification (SRS) as closely as possible.

In a nutshell, an SRS is the blueprint of your software. It describes what it should do and how it will do it.

These are all agreed upon by the client and the development team so everyone is on the same page.

Software requirements infographic

Source: Lucidchart

The critical part of an SRS is defining the exact purpose of the software.

This is useful for the development team so that every action and decision they make is towards fulfilling that singular goal as intended by the client.


Efficiency is another basic characteristic of a great custom software solution. It means the software runs smoothly and responsively, even with large transactions or network traffic.

This is a critical quality because it ties in with usability. If custom software is sluggish, it will quickly frustrate the user, no matter how great or innovative the features are.

One example that illustrates this is the failed launch of healthcare.gov by the US government. The site was meant as a portal where Americans can compare and enroll in healthcare plans.

But poor system design, inadequate testing, and insufficient infrastructure caused numerous performance issues like crashes and long wait times.

Many prospective users couldn’t even complete the enrollment process.

the system is down at the moment

Source: Harvard

To prevent a similar disaster, all custom software should be thoroughly tested before launch.

Performance test methods like scalability, load, and stress testing allow you to evaluate how well your software runs when put at the breaking point.

You should use development best practices that could improve the efficiency of your app.

For instance, one good way to speed up your software is to streamline your UI. Too many on-screen elements can bloat your load times, making your software unresponsive.

It’s also good to constantly monitor critical performance metrics, such as latency.


Reliability is a measure of your software’s uptime—the period it can operate without failure.

This is an important characteristic because crashes and outages can be incredibly frustrating for a user. This is especially true with software solutions that are mission-critical.

For instance, can you imagine if you needed to pay something and suddenly your banking app crashed?

Or what if you need immediate medical attention but can’t retrieve your patient details through your healthcare app because it’s down?

Of course, software that has 100% availability isn’t realistic. Unexpected and mostly uncontrolled events do happen that can bring software down.

Thus, a better goal would be to have 99.999% availability—or what is known as five-nines availability. Anything lower than 99% is generally considered bad.

And if you think the decimal place is negligible, there’s actually a huge difference between 99.9% and 99.999% availability, as shown in the chart below:

The nines of availability

Source: BMC

But if the software does go down, it’s critical that you can fix it as soon as possible to minimize downtime.

One useful metric for this is mean time to recover (MTTR), which measures the average time your development team can repair mistakes.


Security is vital in every software, not just in mission-critical niches like finance and healthcare.

That’s because most modern software includes plenty of sensitive, personal information. This is a data goldmine for hackers, which they could use for other cyberattacks like phishing.

What’s more, data breaches can be very expensive. In addition to the ordeal of losing customer trust and revenue, regulatory bodies and governments impose hefty fines on software without adequate data privacy safeguards.

For instance, here are the fines levied by the EU’s General Data Protection Regulation (GDPR):

two tiers of GDPR fines general data protection regulation

Source: Data Privacy Manager

Security must be a top priority for developers because improper coding practices can make the software more vulnerable.

For example, SQL injection is a common hack where hackers can access the database by making unauthorized SQL queries.

While deadly, it’s easily preventable with the right coding technique.

You should also be wary of using third-party APIs and libraries because these could offer back-door access to your software.

Make sure the developers of these add-ons have the same security standards as you.

Finally, security should extend beyond the software and into the infrastructure. After all, what’s the use of secure software if a hacker can easily breach your network?


Usability refers to how easy and intuitive your software is to use. This is vital because even the most functional software would fail if it’s a pain to use.

A usable piece of software is one where the user interface adapts to the person’s needs and not vice versa.

In other words, a user should not have to exert much effort trying to learn and use your software.

This can be achieved by removing cognitive barriers and factors that increase cognitive load.

The easiest would be eliminating unnecessary steps whenever users accomplish a task in the software.

Cognitive Barriers vs Cognitive Load

Source: UX Mag

But usability goes beyond just the user interface and visual elements. It encompasses the entire user experience.

Take online capabilities, for instance. Even if an app is online dependent, it should still be responsive even if it goes offline.

Software solutions like Evernote, for example, accomplish this through offline sync.

That way, users can still write notes and use most of its features. It will just simply synchronize any edits made once it goes back online.

offline sync for a mobile app

Source: Yalantis

There are other UX best practices that can contribute to a usable app, such as intuitive navigation, sensible notification schedules, and UX copywriting.

UX might be comprehensive, but it’s well worth the effort. After all, studies show that you get $100 for every $1 you invest in UX.


Most modern software solutions don’t operate alone. The typical user now requires multiple applications to accomplish their tasks.

Thus, compatibility is a consideration when designing custom software.

Compatibility can make custom software more successful by allowing users to integrate it into their existing workflow rather than replace it entirely.

That makes it easier for people to accept the new software, improving the usage rate.

Tight integration also helps people and organizations to be much more efficient.

Slack is perhaps one of the best examples of this benefit in action because it supports over 2,600 apps and platforms.

For instance, you can connect Slack to Todoist, a to-do list platform. That allows users to add tasks to the list right from Slack, saving them the time and effort of doing it manually.

connect Slack to Todoist

Source: Todoist

To ensure compatibility, you need to consider how your market is using your software. Are they using it with other apps? What tasks are they doing manually that integration can speed up?

Once you identify these opportunities, you’ll know which software integrations you must focus on to deliver the best user experience.


Portability is the characteristic that makes software easy to transfer from one environment to another.

This is critical because your users work with different combinations of hardware, operating systems, resolution, and controls.

Thus, the more portable your software is, the more users you can cater to and the more revenue you’ll see.

It’s one of the reasons why web apps and software-as-a-service platforms are very popular right now.

Non SaaS application vs. SaaS application

Source: Cloudflare

SaaS, by nature, is portable because it’s platform-independent. It doesn’t matter which OS or device you access it from—as long as it has a browser.

So SaaS is a good approach if you’re after portability.

For apps, another consideration is going the cross-platform route.

Here, you develop a mobile app once, then use a cross-platform tool like ReactNative or Flutter to compile it into iOS and Android apps.

While not portable in the truest sense, it does provide the ease of writing code once, then deploying it anywhere.


As we discussed at the beginning of this article, scalable software can easily adapt and change based on a company’s needs.

For instance, let’s say your custom web app can only accommodate 10,000 concurrent users.

However, you expect to get 100,000 users because of a marketing campaign. With scalable software, you can easily increase the load capacity to handle that demand.

The key to this flexibility lies in two things—modular software design and infrastructure.

Modular software comprises components that can be changed independently of the other parts. This makes it easy to change one without affecting the rest of the software.

Layered vs modular monolith

Source: Semaphore

So, for instance, if you only need to upgrade the checkout page on your e-commerce app, there’s no need to touch the Accounts section.

The other factor is infrastructure. Software should sit on hardware easily swapped, upgraded, or downgraded as needed.

That’s where infrastructure-as-a-service solutions like Amazon Web Services (AWS) and Microsoft Azure come useful.

These allow you to host applications on the cloud and consume only the needed resources.

More importantly, they can scale automatically to account for increased transactions.


Your custom software isn’t set in stone when you launch it. Bugs, user feedback, and market conditions will force you to make changes to it.

Thus, maintainability is a good characteristic of any custom software. And it starts with good coding practices.

That’s because, typically, developers are not the ones who maintain the software. There’s often another team that does that. This is especially true if an external team develops the software.

Thus, the code should include supporting documents like interface definitions. This should give the maintenance team a good idea of the logic behind the software’s code.

It’s also critical that development follows a coding standard like the one below:

coding standard

Source: Javascript.info

Coding standards make it easy for another person to understand your code.

It avoids things like ambiguously-named variables and spaghetti logic that could make code difficult to comprehend and edit.

Need a developer that checks all these boxes?

We hope we’ve enlightened you on the nine qualities to look for in your software project.

Of course, knowing about them isn’t enough. You’ll need the right expertise and experience to make these characteristics a reality.

And that’s where a reputable agency like DECODE can help!

With over a dozen successful projects under our belt, we know what it takes to develop software that includes all these nine characteristics.

Interested? Schedule a free consultation with us today (fully NDA’d), and let’s talk!

Written by

Marko Strizic

Co-founder and CEO

Marko started DECODE with co-founders Peter and Mario, and a decade later, leads the company as CEO. His role is now almost entirely centred around business strategy, though his extensive background in software engineering makes sure he sees the future of the company from every angle. A graduate of the University of Zagreb’s Faculty of Electrical Engineering and Computing, he’s fascinated by the architecture of mobile apps and reactive programming, and a strong believer in life-long learning. Always ready for action. Or an impromptu skiing trip.

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