Real-Time Payments
bankingJuly 11, 2025

Real-Time Payments

Architecting for Instant Settlement Reliability

Article presentation
Designing real-time payment systems requires event-driven architecture, in-memory grids, and scalable microservices to ensure speed, security, and resilience.

As global payment schemes adopt ISO 20022 standards and central banks push for instant rails, engineering teams face a new kind of pressure: building infrastructure that’s always fast, always available, and always secure. 

So how do you architect for real-time settlement reliability? 


The Infrastructure Demands of Real-Time Payments 

Unlike traditional batch processing, real-time payment systems require continuous uptime, ultra-low latency, and fail-safe execution logic. You’re not just sending money—you’re sending trust across borders, banks, and devices. 

From an architectural perspective, this means: 

Event-driven systems  

Real-time payments demand instant communication between services, and event-driven architecture is the engine that makes it possible. By decoupling producers and consumers of payment-related events, systems remain responsive and scalable even under high throughput. Tools like Apache Kafka or AWS Kinesis are commonly used to stream messages such as payment initiation, authorization, fraud checks, and settlement confirmation. Each message can trigger its own service pipeline—enabling independent deployment, faster recovery, and built-in auditability. 

This architecture is also key in supporting modular service orchestration—think fraud detection triggering after KYC verification, or settlement updating after real-time currency conversion. Event-driven flows allow teams to scale and evolve individual components without locking the entire platform into sequential or synchronous patterns. 


In-Memory Data Grids for Real-Time State Management 

To minimize latency in financial workflows, systems need to access and update state information—like account balances, transaction history, or session data—without constantly hitting a central database. This is where in-memory data grids such as Hazelcast, Redis, or Apache Ignite come into play. These systems store frequently used data across distributed memory clusters, enabling millisecond access and real-time updates. 

In payment processing, this can power everything from instantaneous balance checks and fraud rule lookups to caching payment gateway responses. By reducing reliance on slower disk-based databases, in-memory layers not only accelerate performance but also add resilience through data replication and sharding. They’re a key building block for systems that require fast state transitions under strict consistency constraints. 


Horizontally Scalable Microservices for Elastic Traffic Handling 

Payment volumes are highly unpredictable—peak times during salary days, promotional events, or cross-border activity can strain even well-architected systems. To manage this, fintech platforms rely on horizontally scalable microservices. These are stateless components that can spin up or scale down based on load, making use of orchestration platforms like Kubernetes or AWS ECS. 

In real-time payments, microservices handle individual responsibilities: payment validation, fraud scoring, message formatting, compliance checks, and downstream API calls. By keeping these responsibilities loosely coupled, systems can route traffic more efficiently, isolate bottlenecks, and reduce the risk of cascading failures. 

Scalability also improves maintainability. Teams can deploy fixes or upgrades to specific services without full-platform redeploys—critical for ensuring uptime in high-availability environments. 


Compliance with ISO 20022 

ISO 20022 is more than a data format—it's a paradigm shift in how financial messages are structured and interpreted. Supporting it means your system must: 

Handle rich, structured data payloads with backward compatibility for legacy formats. 

Ensure schema validation and message transformation in real time, often through custom middleware or integration gateways. 

Maintain audit trails and traceability across systems, enabling regulatory transparency and dispute resolution. 

Ensuring Low Latency Under Load 

Latency in real-time payment systems must be measured in milliseconds—not seconds. Achieving this means: 

Prioritizing non-blocking I/O and async processing, especially for API gateways and transaction workflows. 

Leveraging gRPC or GraphQL for lightweight communication between services. 

Locating critical services close to the user with edge computing and CDN-based caching layers for session validation. 


Operational Resilience and Failover Strategies 

Failures happen—especially when money is on the move. Your architecture needs built-in resilience through: 

Active-active deployments across regions with automated failover and traffic rerouting. 

Circuit breakers and retry logic to handle downstream service degradation. 

Monitoring and observability stacks (e.g., Prometheus, Grafana, ELK) that alert teams in real time when anomalies occur. 


Designing for the Future of Payments 

Instant payments aren’t just fast; they’re foundational to the next wave of financial innovation. Whether you’re building SoftPOS applications, integrating request-to-pay, or embedding B2B real-time transfers, your infrastructure needs to scale with confidence and compliance. 

At OceanoBe, we design payment systems for scale, security, and speed—partnering with banks and fintechs to get real-time right. 

👉 Ready to build an infrastructure that can handle the speed of money? Let’s talk about how we can support your next payment solution.