Comercia scales payments across Europe and beyond

THE CHALLENGE

From legacy constraints to six-nines availability

In the fast-paced European digital economy, the difference between a successful sale and a lost customer is measured in milliseconds. Comercia Global Payments—a strategic alliance between CaixaBank and Global Payments—helps businesses take payments anywhere; in-store, online or on mobile, with its fast, flexible solutions. Processing 3.6 billion transactions and €113 billion in volume across 58 countries annually, Comercia is a mission-critical cornerstone of the modern financial landscape.

For years, the Spanish market relied heavily on a traditional, bank-owned payment ecosystem known as Redsys. While stable, this legacy infrastructure was rigid, slowing innovation. If Comercia wanted to implement a modern feature—such as mobile payments—it had to request from Redsys and wait for approval. Facing a roadmap where new features might be delayed until 2027 and in an environment where rapid innovation is tied to competitive advantage, Comercia made a bold, strategic decision to build its own proprietary payment gateway, ‘Comercia 2.0’, to create a competitive advantage.

However, owning the entire payment stack also placed the burden of availability squarely on Comercia's shoulders. Operating under a strict 99.9999% availability Service Level Agreement (SLA), Comercia knew that even a brief disruption would cause immediate financial and reputational fallout. Relying on a single cloud provider proved too risky; despite a robust setup, a historical outage in Microsoft Azure's database service led to a 15-minute system failure.

"One minute of downtime can generate 20,000 denials, that is, 20,000 sales that failed on our terminals," said Antonio Rodríguez, CTO, Comercia Global Payments.

To survive any single provider’s failure, Comercia needed more than geographic redundancy—it needed consistent, secure, real-time shared data across clouds. This was the most complex challenge of all. Transaction data had to remain continuously available, even if one environment went offline. At the same time, PCI (Payment Card Industry) and GDPR (General Data Protection Regulation) requirements demand strict security controls, and strong consistency had to be preserved across distributed nodes to prevent data conflicts or integrity issues.

In other words, the architecture could not simply replicate data between providers, it had to behave as a single, unified system.

After evaluating its options, Comercia selected MongoDB Atlas to underpin a secure, resilient data layer spanning Azure, Google Cloud, and AWS without compromising consistency, compliance, or real-time performance.

OUR SOLUTION

Deploying a resilient active-active multicloud cluster

The company needed a solution capable of managing a single, consistent cluster across multiple cloud providers and regions, something no other database platform could deliver.

Rather than building and maintaining complex dual-write logic or a self-managed consistency layer, Comercia’s engineering team designed an active-active, multi-cloud cluster orchestrated entirely by MongoDB Atlas. The deployment spans two regions of the Azure global cloud platform, Google Cloud as a secondary active-active provider, and AWS as a tie-breaker node to ensure consistent elections. All nodes operate as a unified replica set, coordinated automatically by MongoDB Atlas.

“MongoDB Atlas was the only database service that allowed us to create a cluster where the nodes are distributed not only across different cloud regions, but also across different clouds,” said Antonio Rodríguez.

Recognizing that a multi-cloud strategy requires more than tooling alone, Comercia partnered with a MongoDB team consisting of Solution Architects, Professional Services, and Technical Service Engineers to embed deep expertise directly into its operations. “With MongoDB, we have support from a team who knows our history, who has helped us build, and who are available not only for incidents but for evolution. MongoDB services and support are on another level.”

This partnership gave Comercia more than a database: it became an extension of the engineering team, ensuring the platform continues to evolve, optimize, and future-proof the company’s high-availability, multi-cloud ecosystem.

OUTCOME

Architecting for continuous availability and growth

With MongoDB managing replication, elections, node prioritization, consistency guarantees, encryption, and cross-cloud networking natively, Comercia eliminated significant operational complexity while achieving an extraordinary six-nines level of availability. The platform operates as a single, cohesive system across two Azure regions, one Google Cloud region, and one AWS region: if any Azure region experiences downtime, traffic shifts seamlessly to another Azure region; if all Azure regions fail, Google Cloud becomes primary, with AWS acting as a tiebreaker to maintain cluster stability.

Failover happens within two to three seconds, fast enough that customers barely notice, while SLAs are consistently met and PCI and GDPR compliance is ensured. By embedding resilience directly into the database layer, Comercia removed the need for custom failover logic at the application level, ensuring reliability is built into the architecture itself.

This capability extends beyond reactive protection: Comercia can proactively shift traffic during maintenance or performance-intensive operations, such as building large indexes, without impacting live production. Zero-downtime operations, proven in the past 30 months of operation, are now an operational reality.

By removing single-provider dependency, Comercia has unlocked operational agility and dramatically reduced risk. The company’s worst-case scenario—a payment gateway outage while competitors remain online—is now far less likely, giving both the business and its customers confidence. New environments can be launched in days rather than months, enabling rapid market expansion and the potential to consolidate dozens of regional payment systems into a single, unified platform.

“We can deploy in Spain, France, Poland, all unified through a single MongoDB Atlas platform built to scale across Europe and globally, processing billions of operations each month,” said Rodríguez.

Owning its multi-cloud data infrastructure also gives Comercia greater autonomy to innovate, free from previous provider constraints, and to deliver new payment features and services faster than ever. In taking full control of its platform, Comercia hasn’t just safeguarded uptime; it has created a resilient, scalable foundation for sustained European expansion and future global growth. Put simply, “MongoDB Atlas has been a game-changer for us,” concluded Rodríguez.