The Best Custom Software Development Companies in Spain in 2026

Picture a retailer with a few shops and an online store writing to a software company: they want an internal CRM for customers, orders, stock and suppliers, and an app their customers can use. They have one systems technician in-house. Their questions arrive in this order — phases, hosting, maintenance, payment terms, contract, grants, and «a price range». Not one of them is about the technology.

That is the buyer this guide is for: an established Spanish company, not a startup, commissioning custom software for the first or second time. And the number that should frame the choice is not a ranking. The Standish Group's CHAOS 2020 report, built on 50,000 project profiles, found that only 31% of software projects are delivered on time, on budget and with the agreed scope; 50% arrive late, over budget or cut down, and 19% fail or are never used. Two out of every three custom software projects do not land the way the contract said. The best company for you is the one whose process puts you in the 31%.

One disclosure: Conectia is on this list, in the row where we fit, and the profile below also says when we are not the right call. Weigh it against the verifiable columns, not our say-so. If you are a funded startup rather than an established company, our map of software partners for startups in Spain and the EU is the better read.

Ten custom software companies in Spain, compared by fit

Three columns decide the project, and size is not one of them

«Best for» is the column that saves you three months. The ten companies above are not ranked from worst to best; they are sorted by the kind of buyer they are built around. A 3,000-person group can build your CRM, but your project will be small inside it, and small projects inside large organisations get the team that is free, not the team you met. A ten-person studio can be the most attentive partner you will ever have, and still lack the depth for an integration that touches payments, stock and a customer app at once. Match the size of the company to the size of the problem.

«Who does the work» decides whether anyone remembers your system in year two. Custom software is not delivered once; it is delivered, then maintained, then changed. An in-house team that stays on the account carries the knowledge of why the stock module behaves the way it does. Before signing, ask for the names of the people who will build it, and whether those same people will maintain it.

«How it starts» is the honest signal of confidence. CHAOS has shown the same pattern for years: small, well-defined projects succeed far more often than large ones. A company that opens with a short, written first step — a specification, a pilot, a first module in production — is betting that its work survives contact with your business. One that opens with a full-scope fixed price and a twelve-month plan is asking you to carry the 69%.

The ten, profiled

1. Conectia — best for an SME that wants the system built and run by one senior team. We build web platforms, internal tools, customer portals and the integrations between them, with AI features where they cut real work: document handling, customer service, internal search. The stack is deliberately narrow — Node.js and TypeScript, Python, cloud infrastructure and DevOps — because that is where our engineers are senior. They are directly contracted across 14 countries, pass a CTO-led five-pillar vet with a 3% acceptance rate, and work in English and Spanish. The engagement starts small: a written Blueprint of the product that any team can build from, then a 14-day pilot sprint, then an MVP in production in six weeks, with a 30-day replacement guarantee on every engineer. When we are not the right call: if you need a WordPress or PrestaShop shop, a native iOS app, a customised ERP, or a team physically in your office every day, choose a company from further down this list.

2. Solusoft — best for a long-standing local consultancy. Based in Leganés (Madrid) and building custom software since 1994, Solusoft reports more than 350 client organisations across Spain, with work in custom development, geolocation systems, mobile apps and web, and sector practices in industry, engineering and utilities.

3. Solbyte — best for SMEs in Andalusia. A Málaga company active since 2006, with around 50 professionals covering custom software, web, e-commerce, mobile apps, and newer artificial-intelligence and cybersecurity departments. It holds ISO 9001 and ISO 14001 certification, and its founder received the Premio Pyme from Expansión. Suits a company that wants one local vendor for the whole digital surface.

4. Zentense — best for management software and intranets in Barcelona. Founded in 2001 by engineers from Spain's first internet providers, Zentense builds custom web software, business-management tools and intranets, e-commerce with payment-gateway integration, and integrations between existing systems. A good match for a Barcelona company replacing spreadsheets with its own tool.

5. Omatech — best for web-heavy projects. Building web projects in Barcelona since 2001, with a team of around 30, Omatech combines complex websites on its own content-management system with corporate applications and APIs and back ends for mobile apps. The right call when the website and the application are the same project.

6. Apiumhub (Plain Concepts) — best when architecture is the risk. Founded in Barcelona in 2014 and known for its focus on software architecture, estimation and quality practices, Apiumhub brought more than 150 professionals into Plain Concepts in August 2025. Choose it when the hard part of your project is getting the structure right, not the screens.

7. Plain Concepts — best for Microsoft-stack and advanced-technology projects. Founded in 2006 by four Microsoft MVPs and now over 700 people, with offices in Madrid, Barcelona, Bilbao, Seville and León, Plain Concepts builds custom software alongside AI, big data, cloud and augmented-reality work. A natural partner if your company already runs on Microsoft.

8. Hiberus — best for a large group with an SME door. The Zaragoza technology group has more than 3,000 professionals and 36 development hubs, and runs Hiberus Booster, a unit dedicated to apps and custom software for SMEs and startups. It offers the reach of a large group through a unit sized for smaller clients.

9. Sngular — best for data and AI programmes. A Madrid technology company with more than 1,300 employees across Europe, the US and Latin America, listed on BME Growth since December 2021, focused on software engineering, data and AI. Built for mid-size and large companies running several initiatives at once.

10. Izertis — best for corporate breadth. Founded in Gijón in 1996, with around 2,700 professionals and a move from BME Growth to the continuous market in July 2025, Izertis covers software engineering, cloud, cybersecurity and business solutions. The right choice when procurement wants one supplier for many things.

How to choose, in four questions

1. What exactly are you buying? Write one page: the three things the software must do on day one, who uses it, and which systems it has to talk to (your online store, your accounting package, your payment provider). If a company cannot price a first phase from that page, it is not ready to build from it either.
2. Is the first step small enough to walk away from? A specification, a pilot or a first module in production, with a written success criterion. That is how you stay in the 31%.
3. Who maintains it, and on what terms? Hosting, backups, security updates and small changes should be in writing before the build starts, with a monthly figure you can plan for.
4. Who owns the code? The repository, the cloud account and the domain should be in your company's name from the first commit.

For the money side in depth — phases, hosting, maintenance, payment terms, contracts and the grants available to Spanish SMEs — read our guide to custom software for SMEs, and for price ranges built from hours and rates, what an app costs to build in Spain in 2026.

Questions Spanish SMEs ask before hiring a software company

Is it better to hire a local company or a remote team?

Local matters for workshops and for the first weeks of discovery; after that, what matters is overlap in working hours and a named team. A remote senior team with full overlap with Spanish hours can serve a Spanish SME as closely as an office down the street, and a local company can staff your project remotely too. Ask where the people who will write the code actually sit, and when they are available.

What should a custom software contract include?

At minimum: the scope of the first phase with acceptance criteria, payment tied to delivered milestones, ownership of the code and accounts, the maintenance terms after delivery, and what happens if a key engineer leaves. If any of the five is missing, add it before signing.

Pick the process, not the logo

Every company on this list builds real custom software for real Spanish clients; the right one depends on the size of your problem and how you want to start. If you are an SME that wants a senior team to build the system, run it, and start with a step small enough to walk away from, that is the standard to measure every proposal against — ours included.

If that is the system you need, talk to Conectia about the first six weeks.