Interfaces and Integrations for Your B2B Shop

Every system landscape is different. Across more than 50 B2B projects, we have encountered the most common integration requirements and developed proven approaches for each type. The following overview shows the six most important integration scenarios that we implement in virtually every B2B project.

Choosing the right integration protocol depends on the capabilities of the systems involved, the requirements for latency and data volume, and the industry-specific standards in play. In practice, we employ the following integration patterns, often combining several within a single project.

We address these challenges through a dedicated transformation layer that mediates between source and target system. In this layer, field mappings, value conversions, unit transformations and business rules are defined and documented centrally. Changes to the data structure of one system require adjustments only in the transformation layer, not across the entire integration. This pattern has proven particularly maintainable in our projects, as new fields or changed logic can be added without reimplementing the interface.

Interfaces are the most critical component of a B2B e-commerce architecture. When an integration fails, orders stall and data drifts apart. That is why we rely on proven design patterns that prioritize reliability, traceability and maintainability. Our integrations use message queues (RabbitMQ, Apache Kafka) for asynchronous processing, ensuring that a temporary outage of a target system does not cause data loss. Idempotent API calls prevent repeated transmissions from creating duplicates. Comprehensive logging and monitoring allow us to detect errors early and pinpoint their cause precisely. As part of our performance and monitoring services, we continue to monitor your interfaces well beyond go-live.

Not every data flow requires real-time synchronization. Choosing the right synchronization mode is one of the most important architectural decisions in integration projects. Real-time synchronization (event-based or webhook-driven) is essential for stock levels, prices and order status, since your customers expect current information in the B2B portal. Batch synchronization at defined intervals is better suited for master data reconciliation, product catalog updates and statistical evaluations where a delay of minutes or hours is acceptable.

In practice, we combine both modes within a single integration. For example, price changes in the ERP trigger an event that updates the affected prices in the shop immediately, while a full catalog reconciliation runs as a nightly batch job. This hybrid architecture significantly reduces system load compared to pure real-time synchronization while still ensuring that business-critical data such as inventory and prices remain current. The intervals and triggers are aligned with your team to match the specific requirements of your business processes.

In production integration environments, errors are inevitable: an ERP system may be briefly unreachable during an update, a data record may contain invalid values, an API rate limit may be exceeded. What matters is not whether errors occur but how the system handles them. Our integrations implement a multi-tier error handling concept that distinguishes between transient and permanent errors.

Transient errors such as network timeouts or temporary system outages are automatically retried via an exponential backoff mechanism. The failed message remains in the message queue and is reprocessed after increasing wait intervals. Permanent errors such as invalid data are moved to a dead-letter queue and reported to your team via a monitoring dashboard. Every error is logged with full context: timestamp, affected record, error type, HTTP status code and the number of retry attempts so far.

Choosing the right integration approach depends on the complexity of your system landscape, requirements for latency and reliability, and your budget. The following overview helps with orientation.

Open-ended effort estimates offer little help when planning a budget. That is why we name clear fixed prices for the most common connections. The final price depends on your system landscape and critical data flows and is fixed after a free integration analysis — with no hidden items. Where useful, we bundle the ongoing operation of your interfaces with our maintenance and monitoring services.

B2B data flows carry business-critical information: customer pricing, order data, accounts receivable master records and invoice details. The security of this data is our highest priority. All interfaces use encrypted connections (TLS 1.3), and API access is secured via OAuth2 tokens or dedicated API keys that are rotated on a regular schedule. IP whitelisting and VPN tunnels provide additional protection for sensitive connections, and access logs document every data operation for complete traceability.

For system-to-system authentication, we employ different methods depending on security requirements and system capabilities. OAuth2 with the client credentials flow is the preferred standard for modern API-to-API communication. For SAP systems, we use certificate-based authentication or SAP-specific token mechanisms. For SFTP-based integrations, SSH key pairs are employed. Every authentication method is configured so that credentials never appear in plain text in configuration files or logs.

For GDPR-relevant data flows, we implement pseudonymization mechanisms and access logging. Retention periods for transaction logs are coordinated with your legal department. For the DATEV connection, we ensure GoBD compliance so that document data is archived in an audit-proof manner and the automated document export meets the requirements of the German tax authorities.

Additionally, we define a detailed error escalation concept for every interface. Critical errors such as failed order write-backs are reported immediately via email and optionally via webhook to your team. Less critical warnings such as temporary timeout errors are logged and displayed in aggregate on the monitoring dashboard. This way, you maintain a constant overview of the health of your entire integration landscape.

In our projects, we consistently encounter similar integration challenges that are relevant across industries. A typical scenario is bidirectional inventory synchronization between shop and warehouse management. When a customer places a B2B order, the inventory in the ERP must be reserved immediately to prevent overselling. At the same time, inventory changes from the ERP, such as goods receipts or manual corrections, must be reflected in the shop promptly. We implement such scenarios via event-based synchronization with configurable thresholds and automatic conflict resolution.

Another common scenario involves customer-specific pricing. B2B prices are rarely static: framework contract conditions, volume pricing, special agreements and time-limited promotions must be queried from the ERP in real time and displayed in the shop. The challenge lies not only in the technical connection but also in performance: when a catalog of 50,000 items needs to calculate individual prices on every page view, intelligent caching strategies and asynchronous price queries are critical for the user experience.

The third core scenario is document and record synchronization. Order confirmations, delivery notes, invoices and credit notes are generated in the ERP and should be available for download as PDFs in the B2B customer portal. The integration encompasses automatic assignment to the correct customer account, archiving according to compliant retention periods and optional customer notification when new documents are available. This document synchronization significantly reduces manual effort for the sales support team and increases customer satisfaction through instant document availability.