More consistent data
The integration reduces duplicates, mismatches and errors when moving information across CRMs, forms, payments, internal tools or products.
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Freelance service
API integrations
Connecting websites, CRMs, payments, forms, ERPs, databases and external tools.
- Free initial assessment An initial conversation to clarify the most useful next step.
- Direct communication You speak with the person analysing and building the work.
- Clear ownership Code, accounts, access and handover are defined.
Problem and outcome
Which manual work should an API integration remove?
The scope is built around a real problem and a verifiable outcome, not a generic list of tasks.
Problems it solves
Your tools hold useful data, but they do not talk to each other in the way your workflow needs.An API integration connects tools so data can move between systems without manual copying, exporting or reconciliation.
It may involve consuming a third-party API, creating your own endpoints, receiving webhooks, transforming data, syncing states or exposing a small interface to supervise the flow.
Less manual dependency
Important changes can travel through an API or webhook instead of waiting for an export or manual review.
Failure behavior included
I define validation, retries, visible errors and limits so the integration remains operable when something external changes.
Guide price
What makes a business-system integration more expensive?
Three ways to start depending on the size of the need. Prices are indicative and final scope is agreed after the initial assessment.
One-off intervention
A technical review to clarify contracts, authentication and integration risk.
From
€250
+ VATWhat is included
- Review of current documentation and contracts.
- Test of authentication or a critical request.
- Plan for errors, retries and required data.
Boundary: This does not include the full integration or undocumented provider changes.
Ask about this interventionComplete project
The most common optionAn operational integration with visible state, errors and traceability.
From
€450
+ VATWhat is included
- Client code and data contracts.
- Authentication, validation and error handling.
- Safe retries and technical logging.
- Tests and deployment of the agreed journey.
Boundary: This does not include provider fees or endpoints outside the agreed scope.
Request a project assessmentMonthly support
Monitoring and evolution of an integration already in use.
From
€149 /month
+ VATWhat is included
- Review of errors and provider changes.
- Contract and credential updates.
- Small observability improvements.
Boundary: This does not include on-call cover or major API migrations within the fee.
Ask about monthly supportService scope
Which contracts, data and failures are included?
Final pricing depends on scope, integrations and project state. If it does not fit, I will say so before estimating.
Work included according to scope
- REST API clients, server endpoints and webhook receivers.
- Data mapping between third-party tools and internal models.
- Retry, validation and error handling for important flows.
- Documentation for environment variables and operational behavior.
Boundaries we put in writing
- This does not include the full integration or undocumented provider changes.
- This does not include provider fees or endpoints outside the agreed scope.
- This does not include on-call cover or major API migrations within the fee.
Integration risks
Where integrations fail beyond the happy path
A connection is not complete when one request returns 200. Data ownership, retries and exceptions still need explicit rules.
Failures the design must cover
- Events repeated or received out of order.
- Expired credentials and supplier rate limits.
- Partial records nobody can reconcile.
Acceptance criteria
- A contract and owner for each data field.
- Tested errors, retries and idempotency.
- Enough traceability to repair a failure without guessing.
Process
How I validate an integration before giving it autonomy
I work on integrations from the data contract and failure cases, not only from the happy-path API call.
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Review the API docs, authentication and limits before committing to the flow.
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Define the data contract and failure behavior.
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Build the integration in a way that is testable and observable.
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Validate real requests and document how to maintain it.
Related proof
Backend integrations and contracts in practice
I write about backend work, tools, automation and practical decisions while building software.
Related article
Idempotent APIs that survive retries
Patterns that prevent duplicate payments, orders and jobs.
Read articleDecision guide
Connect the tools your business already uses
A practical path for connecting forms, CRM, payments, ERP and data without creating more manual work.
FAQ
Questions before connecting two systems
Can you work with messy API documentation?
Usually, yes. I start by validating the real requests and constraints before building too much around assumptions.
Do you only build backend integrations?
No. I can build the backend integration and the frontend screens needed to use or monitor it.
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Does this fit your project?
Tell me what you want to build, what you have now and what outcome you need. If it fits, I’ll suggest a clear next step.