From Osona (Barcelona), we build software for businesses across Spain and other countries
We develop web applications, mobile apps, and AI-powered tools that automate processes and enhance business operations.
We develop online tools and platforms, whether public-facing or for internal business use, across all types of projects.
We design and develop cross-platform, hybrid apps for iOS and Android, available on the App Store and Google Play.
We develop websites optimized for performance, SEO, security, and a functional user experience. For projects that require more than just WordPress.
Automating repetitive tasks through software helps optimize business processes and improve system connectivity.
Moving data from an old program to the new one without losing any of it along the way, and connecting systems that currently don't talk to each other.
At Gilsys, we specialize in developing technology solutions designed from scratch to meet the specific requirements of each project.
Custom software is the development of applications and tools that do not yet exist, built from scratch for a specific business, around its own processes and data. At Gilsys we have a team of developers specialized in different programming languages and frameworks, which allows us to take on small and large projects in any sector: programming cuts across all of them.
While these may seem like similar concepts, it's important to highlight that custom software is created from scratch, whereas personalized software involves adapting or extending an existing tool to meet client needs. There is no one-size-fits-all solution: depending on the project, it may be better to develop custom software or use customizable software as a base.
The technologies section has the details. In short: on the server we work with PHP, usually on Slim Framework when the project is split into an API and a frontend; for the interface we use React with Mantine, and Astro for websites where performance comes first. Responsive design, with Tailwind or Bootstrap, and databases, MySQL, Oracle or MongoDB. For mobile apps, React Native. New projects are built with React; we maintain and extend existing ones in Angular, and we still develop in Java when the project calls for it.
Unique solutions to meet the specific needs of every company.
Custom software development adapts better than commercial solutions. Each project is designed and developed together with the business to meet its specific needs. When needed, technology consulting turns the ideas into planned projects.
Custom development eliminates the limitations of standard software. Designing intuitive, tailored interfaces enhances usability, boosts team efficiency for internal tools, and improves user experience for platforms and apps.
Because we control the source code, we can build advanced, customized features for the specific needs of each project, with solutions as simple or as complex as required, even integrating AI.
Custom software gives full control over the source code and its updates. At Gilsys we also work with version control, and every version is released with continuous integration and automated tests, to keep problems to a minimum.
Custom-built solutions are designed to evolve alongside each project. Applications can be expanded or modified to incorporate new features, integrate emerging technologies, and scale in terms of infrastructure.
Custom development does exactly what is needed, no more and no less. It solves a specific part of the work, so whoever asked for it is more productive and human errors are reduced.
Innovative technologies such as modern frameworks and artificial intelligence can be built in, preparing the software for the business’s current and future needs. At Gilsys we also follow what is new in the sector and propose adopting whatever can add value to each project.
Custom software development enables seamless integration with existing business systems and tools, enhancing connectivity and optimizing workflows without disruption. To connect them, we provide custom API development.
Custom software eliminates recurring licensing costs and forced adaptations, often providing a more cost-effective and sustainable solution in the long run.
Discover how custom software overcomes initial hurdles to deliver long-term benefits.
Custom software requires a higher initial investment compared to standard solutions. This is because the development is fully tailored and built from scratch. However, in the long run, costs are reduced by eliminating recurring license fees, adaptation costs, and third-party dependencies. You can see in detail what drives that investment.
Building custom software can take longer than implementing an off-the-shelf solution. At Gilsys, we use agile methodologies to ensure an efficient process and prioritize critical functionalities, allowing phased implementation.
Unique code can create some dependency on the team that developed it. At Gilsys we hand over the code, which belongs to the business and is documented, and, if needed, we offer separate training for the technicians who will carry on with the project, whether they are in-house or from another company.
Adopting a brand-new tool may require an adaptation period for end-users. We develop intuitive interfaces and provide specialized training to ensure a smooth transition. Additionally, we can adjust the software after deployment based on user feedback.
We build AI-assisted code reviews into our work
We follow good programming practices and keep security in mind in every tool we develop.
An AI agent briefed with our criteria audits the code for problems and delivers a report with what it has found.
We go through that report by hand: we assess what is a real problem, decide how to fix it, apply the changes and run the review again, until we are satisfied with the result.
On request, we also review the server with AI and with OWASP ZAP, to detect the problems most exposed from outside.
We are not a cybersecurity company: for projects with sensitive data we recommend that our clients also commission an external review from a specialized company. Not because we do not trust our own judgment, but to get a second validation.
Deployment and continuous integration
Every version is released through an automated process, not by hand. This avoids the classic "it stopped working because we forgot something in the update", and improvements can be released more often.
We work with Plesk, Docker, GitHub, Amazon AWS, Azure, VPS or whatever infrastructure the company already has or each project requires. It's one of the factors that determine the price of a development.
Discover What Makes Us Different
More than 20 years developing custom software for businesses in very different sectors.
We are often asked to continue a project that another company had started and that was not delivering the results the client expected. Those clients still work with us, which is the best proof that we deliver what is expected.
AI has brought many people and companies who program or advise without in-depth knowledge, through what is known as vibe coding. It is a respectable idea: they have discovered how to create tools without knowing how to program. Precisely for that reason, without in-depth judgment, those tools are neither scalable nor maintainable once they are used in production. We offer more than 20 years of judgment and rigor.
We do not propose what is not necessary, which is why our client relationships are long term. We are sometimes asked to quote for features that could be approached more simply and at a lower cost, and we say so honestly. Likewise, when a development is planned too simply and, according to the roadmap, would have to be rebuilt in later phases, with the consequent loss of the initial investment, we recommend a phased project plan.
We are not a large international consultancy, nor do we aim to be. We have more than 20 years of experience and work to the standards of the largest projects, at the rates of a company of our size.
After delivery, we remain available to evolve the software as your business grows, with new features, and we offer preventive and corrective maintenance whenever it is needed, never as an obligation.
We prepare a tailored quote based on your specific needs.
It makes it possible to build tools by programming directly with AI, without writing or understanding the code. Suitable for testing an idea, but with real risks in production.
Jev, by TypeSafe AI, receives data and returns the best option with its confidence level. We analyze what it brings and where it fits in automations, agents, applications, and data, with a real use case.
Discover how Gilsys, Prestashop experts, program custom plugins to adapt your store to your business needs.
We program custom plugins for WooCommerce, an e-commerce platform we are experts in, to tailor your online store.
