Enterprise Construction Microservices & ERP Integration Layer
Construction · API & System Integration — Five independently deployable microservices integrating a construction company's live systems — ERP, accounting, subcontractors, documents, and field data — without disrupting a single day of operations.
A well-established construction company with a dedicated internal technology department reached out to J14 Design with a specific and well-scoped mandate: they did not need an outside team to rebuild their systems. They had internal engineers capable of maintaining and developing their core platform. What they needed was a specialized partner to design and deliver the microservices layer responsible for integrating their existing systems with a set of external platforms — without disrupting ongoing development work, without creating architectural dependencies the internal team could not maintain, and without introducing technical decisions that would create long-term constraints. This was a technical partnership engagement, not a full-project takeover.
The Challenge
Integration complexity on top of a live production environment. The construction company's core platform was actively managing project timelines, procurement, subcontractor coordination, field reporting, and document workflows across active job sites. Any integration work had to happen without compromising the stability of those running systems.
- ERP connectivity — field and operational data generated outside the ERP needed to flow into it reliably, with transformation logic that respected the ERP's data model without requiring modifications to the core platform.
- Third-party subcontractor management platform — connected to internal project assignments and approval processes for onboarding, compliance tracking, insurance verification, and payment workflows.
- Accounting system synchronization — financial data including purchase orders, job cost allocations, invoice approvals, and payment status needed to synchronize bidirectionally with conflict resolution and audit trails.
- Document management and e-signature service — contracts, change orders, and compliance documents needed to push to a cloud service with status callbacks updating the internal system.
- Field reporting and mobile data aggregation — data captured by field supervisors through mobile devices needed to reach backend systems in structured, validated form with logic to handle intermittent connectivity from remote job sites.
The Architecture
J14 Design delivered a domain-driven microservices architecture in which each integration concern was isolated into its own independently deployable service unit. Rather than building a monolithic middleware layer that would become a shared dependency across all integrations, each service owned its own configuration, retry logic, error handling, and interface contract. Single Responsibility: each microservice owned exactly one integration domain. Contract-First API Design: OpenAPI specification documents were produced before writing any service implementation code, allowing the internal team to review and validate before a line of code was committed. Idempotent Operations: all data synchronization operations were designed to be safely re-runnable. Event-Driven Communication: services communicated through an event queue rather than direct API calls. Circuit Breaker Pattern: each outbound integration implemented circuit breaker logic — preventing cascading failures from propagating into the core platform.
Services Delivered
1. ERP Integration Service
Consumed internal platform events and transformed them into the ERP's expected data format through a configurable field mapping engine.
- Real-time webhook-triggered pushes
- Scheduled batch synchronization for high-volume data sets
- Reconciliation report endpoint to verify sync status and identify discrepancies
2. Subcontractor Platform Bridge
Connected the internal project assignment workflow with the third-party subcontractor management platform.
- Automatic compliance status verification at assignment time
- Insurance validity and onboarding completion checks
- Payment trigger events forwarded to external platform upon internal approval
3. Accounting Synchronization Service
Managed bidirectional data flow between the internal platform and the accounting system for purchase orders, job cost allocations, and invoice lifecycles.
- Staging layer that held records pending validation before committing
- Full audit trail of every synchronization event and conflict resolution decision
- Written to a dedicated log table accessible to both teams
4. Document Workflow Service
Handled the full lifecycle of construction documents requiring e-signature or archival.
- Document push to cloud provider on generation
- Single and multi-party signing sequence logic
- Inbound webhook callbacks to update document status and trigger downstream notifications
5. Field Data Aggregation Service
Acted as the inbound gateway for mobile-captured field data from job sites.
- Payload validation, schema enforcement, and deduplication logic
- Out-of-order delivery handling using sequence numbering and timestamp reconciliation
- Correctly ordered record application after connectivity gaps with zero data overwrite
Key Technical Decisions
- Domain-Driven Service Boundaries: Each service boundary was defined by the business domain it served, not by the technical method of integration. This meant the subcontractor service contained all logic related to subcontractor workflows — regardless of whether that logic involved an API call, a database read, or a webhook.
- Centralized Secret and Configuration Management: All third-party credentials, API keys, and environment-specific configuration values were managed through the company's existing secret management infrastructure. J14 Design's services consumed configuration through environment variables only — never through hardcoded values or checked-in credentials.
- Comprehensive Observability from Day One: Every service exposed a /health endpoint, a /metrics endpoint in Prometheus format, and structured log output with consistent field naming. Baseline alerting rules for error rate thresholds, response time degradation, and synchronization lag were configured before handoff.
Technologies Used
- Node.js
- Docker
- OpenAPI / Swagger
- REST APIs
- Webhooks
- Event Queue Architecture
- Circuit Breaker Pattern
- Idempotent Operations
- Prometheus Metrics
- Structured JSON Logging
- ERP Connector
- E-Signature API Integration
- PostgreSQL
- Environment-Based Configuration Management
Results & Business Impact
- Five independent integration domains delivered as separately deployable, fully documented microservices — within scope, on schedule, and without disruption to the active production environment.
- Internal team onboarding completed in under 3 days — OpenAPI specs, Docker configurations, deployment runbooks, and architectural documentation gave the team complete operational ownership.
- Zero production incidents during the parallel operation periods preceding each service cutover. Every data discrepancy was resolved before cutover, not after.
- Integration failures dropped to near zero — circuit breaker patterns and idempotent operation design eliminated the class of intermittent sync failures that had previously required manual intervention.
- The internal team extended two of the five services within the first quarter after handoff — adding new field mappings to the ERP service and a new document type to the document workflow service — without J14 Design involvement.
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