Enterprise Application Integration
StepTo's engineers in Serbia deliver enterprise application integration: REST/GraphQL APIs, middleware, ERP/CRM integrations, and event-driven architectures.
Reviewed by Igor Gazivoda, Co-founder & CEO of StepTo · Updated
StepTo's enterprise application integration (EAI) work connects the systems a business runs on, ERP, CRM, HRIS, e-commerce, data warehouses, and custom applications, so data flows automatically instead of being re-keyed between silos. We design and build integration layers using REST and GraphQL APIs, message brokers, and event-driven architectures as part of our custom software development services. Our Serbian engineering team (drawn from a national pool of 60,000+ IT professionals) delivers integration work at $35–75/hr for most delivery work, 40–60% below Western European or US consultancy rates. See our fintech payments integration case study for a real example of this kind of work, an event-driven, Kafka-based architecture that let us migrate a legacy payments core one rail at a time in shadow mode, with zero missed or duplicate transactions.
What Integration Services Does StepTo Deliver?
- API development & API gateways: REST and GraphQL APIs with authentication (OAuth2, mTLS), rate limiting, versioning, and developer documentation; gateway setup with Kong, AWS API Gateway, or Azure API Management.
- ERP & CRM integrations: Bi-directional sync between SAP, Microsoft Dynamics 365, Odoo, NetSuite and CRMs such as Salesforce or HubSpot, orders, invoices, customers, and inventory kept consistent across systems.
- Event-driven architectures: Kafka, RabbitMQ, and cloud-native event buses (AWS EventBridge, Azure Service Bus) for near-real-time propagation of business events between services.
- ETL & data synchronisation: Batch and streaming pipelines that consolidate operational data into warehouses (Snowflake, BigQuery, PostgreSQL) for reporting and analytics.
- Legacy system adapters: Wrapping mainframe, AS/400, and file-based systems (SFTP, EDI, flat files) with modern API facades so they can participate in current architectures.
- iPaaS implementation: Configuration and custom-connector development on MuleSoft, Boomi, and Workato where a managed platform fits better than custom middleware.
- B2B/EDI integration: EDIFACT and X12 document exchange with suppliers, 3PLs, and retail partners, mapped into your internal systems.
Which Integration Pattern Fits Your Systems?
- Point-to-point with contracts: For estates of two to four systems, simple, fast to build, documented with OpenAPI contracts so they stay maintainable.
- Hub-and-spoke middleware: A central integration service that normalises data models, so adding a new system means one new adapter instead of N new connections.
- Event backbone: Publish/subscribe over Kafka or a cloud event bus for organisations where many systems react to the same business events (order placed, customer updated).
- Strangler-fig modernisation: An API facade over a legacy monolith that lets you migrate consumers gradually while the old system keeps running.
How Much Does an Integration Project Cost?
- Fixed-scope integration project: Defined systems, defined flows, fixed budget, typical for a first engagement. Rates of $35–75/hr for most delivery work; see pricing.
- Staff augmentation: Integration engineers embedded in your team from $4,500/month per engineer.
- Dedicated integration team: From $13,500/month, the usual model for enterprises with a continuously evolving application estate.
Why Choose StepTo for Enterprise Integration?
- Vendor-neutral: We are not resellers of any iPaaS or ERP, so recommendations are driven by your estate and budget, not licensing commissions.
- Production discipline: Every integration ships with monitoring, alerting, retry logic, and runbooks, the parts that separate a demo from a system finance can rely on.
- CET timezone: Real-time collaboration with European IT departments and 3-4 hours of daily overlap with US East Coast teams.
- Cost structure: Senior integration engineers at a blended $35–75/hr versus $100–200/hr at Western integration consultancies.
How Does an Integration Project Run?
- Systems audit (1–2 weeks): Inventory of applications, data owners, APIs available, volumes, and current manual workarounds.
- Integration architecture: Canonical data model, pattern selection (point-to-point, hub, event bus), error-handling and security design.
- Iterative delivery: Highest-value flows first, typically order-to-cash or customer sync, shipped in 2-week sprints.
- Testing & reconciliation: Contract tests, load tests at production volumes, and parallel-run reconciliation before cutover.
- Handover or ongoing operation: Documentation and runbooks for your team, or continued operation by StepTo engineers.
What Do IT Directors Ask About Systems Integration?
- How much does an enterprise integration project cost?
- A single point-to-point integration (for example, syncing orders from an e-commerce platform into an ERP) typically costs $15,000–40,000 and takes 4–8 weeks. An integration layer connecting five to ten systems through an API gateway or event bus usually runs $60,000–200,000 over 3–9 months. StepTo engineers bill $35–75/hr for most delivery work, roughly 40–60% below Western European or US integration consultancies.
- Should we use an iPaaS like MuleSoft or build custom integrations?
- iPaaS platforms (MuleSoft, Boomi, Workato) are fast for standard SaaS-to-SaaS connectors, but licensing costs grow with connector count and data volume, and complex transformations often end up as custom code inside the platform anyway. Custom middleware makes sense when you have high volumes, proprietary systems, or logic-heavy transformations. We work in both modes and often recommend a hybrid: iPaaS for commodity connectors, custom services for the integrations that carry your core business logic.
- Can you integrate cloud SaaS with on-premise legacy systems?
- Yes. Hybrid integration is the most common scenario we see: a legacy on-premise ERP or AS/400 that must exchange data with cloud CRMs and e-commerce platforms. We use secure agents, VPN or private-link connectivity, message queues for resilience across network boundaries, and file-based or database-level adapters when the legacy system has no API.
- How do you prevent data loss or duplication between systems?
- We design integrations with idempotency keys, transactional outbox patterns, dead-letter queues, and reconciliation jobs that compare record counts and checksums between source and target systems. Every integration ships with monitoring and alerting so a failed sync is detected in minutes, not discovered at month-end close.
- Do you provide ongoing support for the integration layer?
- Yes. Integrations degrade as connected systems change, APIs get versioned, fields get renamed, volumes grow. Most clients keep an integration engineer through staff augmentation from $4,500/month, or a dedicated platform team from $13,500/month for larger estates. Support covers monitoring, incident response, and adapting integrations as upstream systems evolve.