API development and integration services
API development services: build REST APIs and connect payments, CRM, ERP and shipping, with webhooks, docs and monitoring. You own the code.
Software is rarely one system. Orders sit in your store, stock in another tool, invoices in accounting and customers in a CRM. API development builds the interfaces that let those systems exchange data on purpose. Integration connects what already exists. We do both, and we write down what happens when a connection fails.
Two jobs, one page
- API development. Designing and building an interface your own product, your resellers or your mobile app will call.
- Integration. Connecting your system to someone else’s API: payments, CRM, ERP, accounting, shipping, messaging.
What we deliver
- A documented REST API. Resources, authentication, error format and an OpenAPI description other developers can read.
- Third-party integrations. Payments, CRM, ERP, accounting, shipping, email and calendar tools, connected through their official APIs.
- Webhooks. Events pushed to or received from other systems, with signature checks and retries.
- Sync logic. What wins when two systems disagree, how conflicts are logged, how to re-run a sync.
- Monitoring. Alerts on failures and a log you can search when a record goes missing.
- Handover. Repository, credentials, runbook and documentation in your accounts.
What makes an integration hold up
| Concern | How we handle it |
|---|---|
| Duplicate calls | Idempotency keys, so a retry does not create a second order |
| The other side is down | Queues and retries with backoff, plus an alert when retries run out |
| Rate limits | Throttling and batching built to the provider’s published limits |
| Secrets | Kept in environment configuration, never in code or in the repository |
| Provider changes | Versioned calls and a note of which API versions are in use |
| Bad data | Validation at the boundary and a visible reject list |
API design choices we explain
- REST by default, because it is understood by every developer you will hire. If your consumers need something else, we discuss it in the scope.
- Authentication. API keys for server-to-server work, OAuth2 where users grant access to their own data.
- Versioning. Changes that break callers get a new version, so outside developers are not surprised.
- Documentation as a deliverable. An API nobody can read is not finished.
Common integration targets
Payment gateways, accounting tools, CRM and ERP systems, shipping carriers, email and SMS providers, calendar and booking tools, and your own internal databases. If the system has a documented API, the work is predictable. If it has a poor one, we tell you the risks before you commit.
How the work runs
- Brief. Which systems, which data, which direction, how often.
- Written scope and estimate. Endpoints or connections, failure behaviour, milestones and a USD estimate.
- Build in increments. One connection or resource group at a time, each with a recorded demo against test accounts.
- Go-live and monitoring. Switch over with a plan for back-out.
- Handover. Everything documented and in your accounts.
Related services
- Web application development for the interface that sits on top of the API.
- AI automation when the connected data feeds a workflow.
- Shopify development and WordPress plugin development for store and site integrations.
- Mobile app development for apps that call your API.
- Custom software development, the overview.
Frequently asked questions
What is API development?
It is designing and building the interface through which one piece of software lets another read or change its data. A well-built API has clear resources, authentication, errors and documentation.
What is the difference between an API and an integration?
An API is the interface. An integration is the working connection between two systems that uses it. A project can need one, the other or both.
How much does API integration cost?
It depends on the systems, the data volume and how the other side behaves. After a short discovery call you receive a written estimate in USD. There is no price list, because each integration differs.
Do you integrate with systems that have no API?
Sometimes, through file exports, scheduled imports or a database connection. We state the risks of that route in the scope, because it breaks more easily than an official API.
Who owns the integration code?
You do. Repositories, credentials and documentation are handed over. NDA on request.
What happens when an integration fails?
Failures are retried, then reported by alert, and the record is kept in a list you can re-run. The behaviour is written into the scope, not discovered in production.
Send the brief
Tell us which systems must exchange what data, and in which direction. Get a written scope for your API development project.
Brief in. Scope out.
Tell us what you need. We will map out the approach, the stages and a written estimate.
Tell us about your project
Fill in the short form below. We will reply with questions or next steps and, once the scope is clear, a written estimate.
- Service area
- Worldwide (remote)