API Development & Systems Integration
We design APIs that expose your systems to partners, and build the integration layer that connects ERP, MES, WMS, TMS, and third-party platforms that were never designed to share data — built to keep working when the other side changes or goes down.
- API design & contract definition
- ERP, MES, WMS & TMS integration
- Partner & third-party API integration
- Authentication & rate limiting
- Versioning & backward compatibility
API development and systems integration is the design and engineering of the interfaces that let a company's systems, and its partners' systems, exchange data reliably — building APIs that expose a company's own functionality, connecting internal systems like ERP, MES, WMS, and TMS that were never built to share data, and integrating third-party and partner APIs into an existing platform. North Tech Labs builds this as a deliberate contract and architecture problem, not a one-off script that moves data between two systems until something changes.
Business challenges this addresses
- Disconnected systems create duplicate workWhen an ERP, warehouse system, and CRM don't talk to each other, staff re-enter the same order, customer, or inventory data by hand in multiple places, and the copies drift out of sync.
- Partners need access to functionality that was never exposedA customer or partner wants to place orders, check status, or pull data programmatically, but the underlying system was built for internal use only and has no defined external interface.
- A third-party API changed or went down without warningAn integration built against a partner's API breaks when that partner ships a breaking change, hits a rate limit, or has an outage, and there was no fallback behaviour defined for that case.
- Point-to-point integrations have become unmanageableYears of one-off scripts connecting system A to system B, then B to C, leave a tangle of undocumented data flows that nobody fully understands and everybody is afraid to touch.
Capabilities
- REST and GraphQL API design and contract definition
- API versioning and deprecation strategy
- Authentication and authorization (API keys, OAuth2, JWT)
- Developer-facing API documentation
- ERP, MES, WMS, and TMS integration
- Partner and third-party API integration
- Webhook and event-driven integration patterns
- Legacy system integration via adapters and middleware
- Rate limiting, throttling, and quota management
- Retry logic, circuit breakers, and graceful degradation
- Integration monitoring, logging, and alerting
- Data validation and reconciliation between systems
Typical solutions
Examples of the kind of systems this service can build — not a list of completed client projects unless stated otherwise.
- Partner-facing APIA documented, versioned API that lets partners or customers integrate against a company's own systems programmatically, with authentication and usage limits defined up front.
- ERP/WMS integration layerA middleware layer connecting an ERP and warehouse or transport management system so order, inventory, and shipment data stays consistent without manual re-entry.
- Third-party integrationAn integration against an external platform's API, built to handle that provider's rate limits, versioning, and downtime without failing silently.
- Internal integration hubA central integration layer that replaces a tangle of point-to-point scripts with a single, monitored place where data flows between internal systems.
- Legacy system adapterAn adapter layer that exposes a legacy system's data through a modern API, so newer systems can integrate with it without touching the legacy codebase directly.
- Event-driven data pipelineA webhook or event-based pipeline that keeps multiple systems updated in near real time instead of relying on scheduled batch syncs.
Delivery approach
- 1DiscoveryWe map the systems involved, their existing APIs or absence of one, data ownership, and where duplicate work or manual reconciliation currently happens.
- 2Contract designWe define the API contract — endpoints, data model, authentication, versioning approach — or document the integration points if we're working against an API we don't control.
- 3ArchitectureWe design the integration architecture, including how it behaves when a connected system is slow, rate-limited, or unavailable.
- 4DevelopmentWe build the integration in reviewable stages, testing against real (or realistic staging) data from the connected systems as we go.
- 5QAWe test the happy path and, deliberately, the failure paths — timeouts, malformed responses, partial failures, and rate limits.
- 6ReleaseWe roll out with monitoring in place from day one, so integration failures surface as alerts rather than as a support ticket days later.
- 7Ongoing evolutionWe maintain the integration as connected systems change their own APIs, add fields, or deprecate endpoints, so it doesn't quietly break months after handover.
Architecture & engineering considerations
- API contract design & versioningContracts are defined explicitly and versioned from the start, so consumers of the API aren't broken by changes and deprecated versions can be retired on a defined timeline rather than an unplanned one.
- AuthenticationAccess is scoped and authenticated appropriately to who's calling the API — internal service, partner, or public client — rather than a single shared credential for everything.
- Rate limitingAPIs we expose are rate-limited to protect the underlying system, and integrations we build against other providers' APIs respect their limits and back off instead of retrying aggressively.
- Handling partner and third-party failures gracefullyIntegrations are built assuming the other side will eventually be slow, wrong, or offline — with retries, circuit breakers, and defined fallback behaviour rather than an unhandled exception reaching a user.
- Backward compatibilityChanges to an API we own are made in a way that doesn't silently break existing consumers, with deprecation windows communicated rather than endpoints changing without notice.
- Data consistencyWhere the same data exists in more than one system, the integration defines which system is the source of truth and how conflicts or sync failures are detected and resolved.
Where this fits
Is this the right fit?
- A good fit when...You need to connect existing systems that don't currently share data, or expose part of your own system to partners through a proper API rather than ad hoc file exports or shared database access.
- Not a good fit when...The two systems in question already integrate well through an existing, well-supported connector — we'd rather point you to that than build a custom layer you don't need.
- Typical engagement shapeA scoped integration or API delivered against a defined contract, followed by ongoing support as the connected systems themselves change over time.
Related services
- Custom Software DevelopmentDesign and development of secure, scalable custom software for companies across Sweden and the Nordic region.
- Legacy System ModernizationAudit-led legacy system modernization with incremental, strangler-fig migration and phased cutover for companies across Sweden and the Nordic region.
- DevOps & Cloud InfrastructureDevOps engineering for teams with manual, risky deployments: CI/CD, infrastructure-as-code, and observability built as a real discipline.
Frequently asked questions
Can you integrate with our existing ERP or WMS?
In most cases, yes — integrating with existing ERP, MES, WMS, and TMS systems is the core of this work, whether that's through an API the system already exposes or a custom adapter where it doesn't. The specifics depend on what the existing system supports.
How do you handle a partner API going down or changing?
We design integrations to expect it — retries, circuit breakers, and defined fallback behaviour for outages, plus monitoring so a breaking change on the partner's side surfaces as an alert rather than a silent failure discovered later.
Do you design the API contract, or just consume ours?
Both, depending on the engagement. When you're exposing your own functionality, we design the contract — endpoints, data model, versioning — with you. When we're integrating against a system you don't control, we work within its existing contract instead.
What happens when the systems on both sides keep changing?
That's the normal case, not an exception — integrations are versioned and monitored so a change on either side is caught and addressed deliberately, rather than assumed to be a one-time build with no maintenance afterward.
Further reading
- API Design Practices for Long-Lived, Multi-Consumer SystemsA technical reference on API design for systems integrated against for years: resource modeling, versioning, auth, pagination, errors, and compatibility.
- Event-Driven Architecture: When and How to Use ItA technical guide to event-driven architecture: patterns, message broker fundamentals, real tradeoffs, and when to choose events over a synchronous API call.
- Node.js vs. Laravel: Choosing a Backend FrameworkA technical comparison of Node.js and Laravel for backend development - I/O model, ecosystem, hiring, and a practical decision framework.
Considering a API Development & Systems Integration project?
Tell us which systems aren't talking to each other, or what you need to expose to a partner, and we'll review the existing interfaces before proposing an approach.