Integrations that make failure visible and recovery practical.
REST API development and third-party integrations with clear contracts, validation, error handling and traceable data exchange.
Complexity becomes expensive when ownership is unclear.
Integration failures create duplicate work and inconsistent data when retries, ownership and error handling are left implicit.
We define the contract, map failure scenarios and implement validation, idempotency and operational logging appropriate to the connected systems.
See our development processWhen this capability is a practical fit.
Organisations that need api & integrations capability for an important product, operational workflow or existing application.
Delivery connected to the work your teams need to improve.
Less manual re-entry
Defined during discovery and reviewed against agreed acceptance criteria throughout delivery.
Clearer integration support
Defined during discovery and reviewed against agreed acceptance criteria throughout delivery.
More reliable business data flow
Defined during discovery and reviewed against agreed acceptance criteria throughout delivery.
What this engagement can cover.
Scope is shaped around the real requirement. These capability areas help start a focused conversation.
REST API design
Third-party API integration
System-to-system data exchange
Webhook handling
Error and retry strategy
Legacy integration adapters
Concrete outputs agreed before delivery.
The exact deliverables depend on scope; these are established in the written recommendation and project plan.
- Agreed scope, priorities and acceptance criteria
- Architecture and implementation decisions
- Working, reviewed software within the agreed scope
- Test, release and technical handover documentation
Good-fit situations.
- Payment and service integrations
- CRM and operational synchronisation
- Partner portals
- Automated data exchange
Domain contexts.
- Finance and FinTech
- Retail and e-commerce
- Logistics
- Healthcare
- Business services
Verified capabilities selected for the job.
We choose from Hapmexo’s established technology capability based on the existing environment, delivery risk and maintainability.
- REST APIs
- ASP.NET Core
- .NET
- Node.js
- PHP
- SQL Server
- MySQL
From uncertainty to supported software.
Discovery
Business goals, users, existing systems, constraints, integrations and material risks.
Scope and planning
Priorities, responsibilities, milestones, dependencies and acceptance criteria.
Design and architecture
User journeys, solution boundaries, data responsibilities and release approach.
Iterative development
Working software delivered in reviewable increments with visible decisions.
Testing and deployment
Proportionate validation, release preparation and production checks.
Handover and support
Documentation, knowledge transfer and agreed post-launch support.
Controls proportionate to business risk.
We make validation, access boundaries, dependency hygiene, testing and production error handling part of delivery—not a final-week checklist.
- Server-side validation and safe data access
- Clear authentication and authorisation boundaries
- Focused automated tests for important behaviour
- Release, error-handling and recovery planning
Before you start.
Can you integrate with an existing third-party API?
Yes. We review its authentication, limits, error behaviour and sandbox quality before agreeing the integration design.
How do you handle API failures?
The exact controls vary, but common measures include validation, safe retries, idempotency, timeouts, audit records and alerts for failures that require human action.
Can you build an API for our partners?
Yes. We can design a versioned REST API, consistent response model and documentation suitable for approved partners.
Bring the constraints. We’ll help shape the path.
Share the business objective, current system, timeline and the decisions you need to make.
Request a consultation