“Which language should we use to build the next business system?” This is a critical factor in the decision-making process of system development.

The choice of language for developing business systems largely depends on the purpose of the system. For example, what is required for a mission-critical system that causes significant disruption if it stops is completely different from what is required for a speed-focused external portal. For the former, certainty and robustness are paramount; for the latter, development speed and ease of UI creation are key. Compatibility with existing internal environments, such as Microsoft 365, is also an indispensable criterion.

In large-scale projects, language selection is not merely a technical choice; it is directly linked to management decisions regarding the minimization of development and operational risks, as well as the optimization of medium- to long-term costs.

To answer the most pressing question—not just explaining the characteristics of each language, but “which language should be used for which project”—we will focus on and explain the four languages we have utilized extensively in business system development based on over 20 years of experience: Java, C#, VB.NET, and PHP.

The 4 Languages Commonly Used in Business System Development

In our many years of business system development, we have primarily utilized four languages: Java, C#, VB.NET, and PHP.

Each of these has different strengths and characteristics, and they must be used selectively according to the purpose of the project. First, let us briefly organize the basic features of each language and their main positioning in business system development.

Java

The greatest feature of Java is that it has an OS-independent execution environment and operates stably in any environment. It allows the same application to run stably across different operating systems, and ensures extremely high robustness and reliability through strict type definitions and exception handling mechanisms.

For this reason, it has established an overwhelming track record in server-side development for large-scale systems that must absolutely not stop. For example, it has long been adopted in core corporate areas, such as banking accounting systems and stock trading systems in the financial sector, social infrastructure like electricity and gas, and the backends of large-scale e-commerce sites processing tens of millions of transactions. Currently, development using frameworks like Spring Boot enables system construction that achieves both productivity and robustness.

It is one of the most widely used languages in the world and boasts an overwhelming share in the field of enterprise system development. The low risk in talent acquisition and high sustainability when considering long-term maintenance and operation are likely the biggest reasons it is chosen for core systems.

C#

A language developed by Microsoft, C# runs in the .NET environment. It has extremely high compatibility with Windows OS and Microsoft products (Azure cloud, Microsoft 365, etc.). While it once had a strong impression of being for Windows apps, it is now a highly versatile language capable of handling everything from Web systems to cloud-native development.

In the field of business systems, it remains the first choice for developing “Windows desktop apps” such as internal business tools and factory production management systems. Additionally, it demonstrates very high performance in Web system development on Azure, Microsoft’s cloud platform.

Since .NET Core, it has progressed toward being open-source and cross-platform, and the developer population is increasing both domestically and internationally. In particular, seamless integration with the Azure environment offers significant benefits in terms of DevOps efficiency, accelerating its adoption in cloud-native development.

VB.NET

Like C#, this language runs in the .NET environment, but its role is slightly different. Its grammar is close to natural language, making it simpler and easier to learn compared to C# or Java, which is why it is valued.

It demonstrates particular strength in processing that integrates with Excel or Access databases. For the development of internal tools that cannot be fully handled by VBA alone—such as importing data from Excel for aggregation or processing Access data to link with core systems—VB.NET boasts unrivaled strength.

Also, with the end of support for VB6, which was built from the 1990s to the 2000s, VB.NET continues to play an important role in development sites as a recipient for migration to the latest environments while inheriting existing know-how.

While it remains an important option as a migration destination from VB6, the reality is that the number of technicians is smaller compared to C# or Java. Therefore, for new development, it is necessary to consider the difficulty of future member replenishment and team maintenance.

PHP

Originally created to dynamically generate Web pages, PHP is a language that excels in Web development. It has a relatively simple mechanism of generating HTML on the server side and returning it to the browser, and is characterized by excellent development speed and ease of use.

It is used as the foundation language for “WordPress,” the CMS adopted by many of the world’s websites. With the standardization of high-functionality frameworks like Laravel, it is also widely adopted in medium- to large-scale modern Web application development, such as CRMs, SaaS-type reservation platforms, and matching sites. For startups that need to quickly shape ideas or for speed-focused Web service development, PHP remains one of the leading options.

With the LAMP environment (Linux, Apache, MySQL, PHP) as a standard, it is easy to minimize infrastructure costs, making it a compelling choice for SaaS and Web services where initial investment needs to be kept low.

Respective Use Cases

Now, we will explain specifically what kind of projects we have worked on and the reasons behind our language selection.

Estimate Creation Software for Factories and Sales Companies (C#)

This development was commissioned for a desktop app for a manufacturer’s product management. The end client had the following requests:

・ Build software that can be used without an internet connection ・ Output estimates as Excel files in a specified format ・ Centralize management of product information that was scattered across Excel files

To prioritize stable operation in an offline environment and response speed, Web technologies were excluded from the candidates. While C++ has high processing power, it requires significant man-hours for business app development, resulting in higher costs.

Java is also excellent, but for precise control of Excel, which was the core of the requirements, technical effort and risks increase compared to Microsoft’s native languages. VB.NET also works well with Microsoft products, but since this was new development, we selected C# considering its high future expandability.

In conclusion, we conducted development using C# to achieve both development efficiency in the Microsoft environment and long-term viability.

For project details, click here

Centralized Management System for Doctors, Patient Info, and Medication History for Hospitals (PHP)

This development was for a centralized medical information management system for hospitals. Since stable operation across multiple hospitals (environments) was required, it needed to be a Web application, and ultimately PHP was selected.

In medical settings, due to security and budget constraints, PC replacement cycles are long, and it is not uncommon for old browsers like Internet Explorer to be in active operation. Therefore, mainstream JavaScript frameworks in modern Web development (such as React or Vue.js) posed a risk where complex processing required on the browser side could cause slow operation or failure on old PCs.

However, PHP allows for the display of screens that are always fast and stable without depending on the client-side PC specs or browser type. this lack of environmental dependence matched the requirements of the medical field.

For project details, click here

DB Migration for Power/Infrastructure Core Systems (Java)

This development was a project to migrate the database from Oracle to PostgreSQL in a large-scale system responsible for power production and business management. While the goal was to reduce licensing costs, a high level of stability was required as it is a system supporting social infrastructure.

Usually, changing the database type tends to cause data inconsistencies with the program, leading to bugs. With highly flexible languages, errors may not be noticed until actual execution, which becomes a risk in large-scale migrations. In that respect, Java excels in the function (static typing) of checking “whether consistency is maintained” at the stage before executing the program. Leveraging this characteristic, we took an approach to smoothly identify discrepancies caused by the migration at the correction stage and prevent troubles before they happened.

As a result, by combining Java’s solid mechanisms with automation via AI tools, we achieved significant cost reductions while maintaining the stability essential for infrastructure systems.

Migration of Desktop Apps Built with VB6 (VB.NET)

This development was a migration project for a core business application in VB6 that was running on Windows 7. It was a revamp due to the end of support for the OS and language, but complete inheritance of the vast business logic was required.

Usually, rewriting to C# is considered from the perspective of future expandability and talent acquisition. However, this system made heavy use of Japan-specific third-party UI components such as Inputman and Spread. If these were developed in C#, which has a different language structure, the behavior would differ, potentially hindering operations when used by end users.

Since VB.NET is a direct descendant language of VB6 and has extremely high affinity in grammar and specifications, we were able to maximize the migration accuracy using our proprietary automatic conversion tool, and thus proposed development in VB.NET.

Consequently, it became possible to accurately carry over complex calculation logic and UI behavior while significantly compressing development costs and the verification period compared to rewriting in C#.

For project details, click here

Summary

In this column, based on actual development experience, we have introduced the characteristics and case studies of four standard languages for business systems.

To make a project successful, it is essential to assess not only the functionality of the language but also security, cost, and the long-term perspective of “whether engineers can continue to be secured in the future.”

Even if the optimal language is selected, quickly securing high-quality engineers proficient in that language domestically can become the biggest bottleneck determining the success of large-scale projects.

What must be considered simultaneously with language selection is the development resource procurement strategy. If it is difficult to find talent domestically alone, broadening your horizons to utilize offshore development is also an important option for project success. By combining overseas bases that possess abundant young talent and adaptability to the latest technologies, it becomes possible to realize the ideal technology stack while keeping costs down.

At Allexceed Vietnam, based on 20 years of offshore development experience in Ho Chi Minh City, Vietnam, we support the success of our customers’ projects from both sides by proposing “optimal language selection” and “reliable resource procurement” as a set.

If you are considering offshore development, please consult with us here.