Can you integrate with legacy systems?

Often, yes, through APIs, database connections, file exchanges or middleware, depending on what the system supports.

How do you handle integration failures?

With retries, queues, idempotent operations and alerts, so failures are recovered automatically or flagged quickly.

Do you write API documentation?

Yes. Every API we build comes with documentation and examples, often as an OpenAPI specification.

API Design & System Integration Services

09 · Software Development04 of 06

Clean, documented APIs and reliable integrations that keep data flowing between every system.

Most businesses run on many systems that don't talk to each other. We design clear, documented APIs and build reliable integrations between your CRM, ERP, payments, partners and products, with error handling and monitoring, so data stays in sync without manual work.

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What's included

Of endpoints documented: 100%; Of endpoints documented
APIs, so changes don't break clients: Versioned; APIs, so changes don't break clients
Integration monitoring: 24/7; Integration monitoring

Your app

API

Partners

Synced

API design & integrations · illustration

REST APIsGraphQLWebhooksERP integrationCRM integrationPayment integrationAPI documentationMonitoringREST APIsGraphQLWebhooksERP integrationCRM integrationPayment integrationAPI documentationMonitoring

Sound familiar?

The problems we hear most often before someone asks us about API design & integrations.

Data out of sync

Customer details, stock and orders differ between systems because updates don't flow automatically.

Brittle integrations

Quick integrations break silently when something changes, and nobody notices until customers complain.

Partners can't connect

Without a proper API, partners and customers can't integrate with your product.

What's included

Integration audit

Your systems, data flows and where things break today.

API design

Consistent, versioned endpoints designed around real use cases.

Documentation

Clear docs and examples so developers can integrate quickly.

Integrations

Connections to third-party systems, with retries and error handling.

Security

Authentication, rate limiting and least-privilege access.

Monitoring and alerts

Logs, metrics and alerts so problems are caught early.

How we do it

01/ 04

You follow every step live in Mission Control, your project dashboard: tasks, files, approvals and a launch forecast.

1
Map
Systems, data and the flows that need to happen.
2
Design
API contracts and integration designs agreed up front.
3
Build and test
Implementation with automated tests against real scenarios.
4
Monitor
Deployment with monitoring and alerting in place.

100%

Of endpoints documented

Versioned

APIs, so changes don't break clients

24/7

Integration monitoring

Built for

Who this is for.

Businesses with disconnected systems

SaaS products opening an API to partners

Companies integrating an ERP

Teams replacing fragile integrations

Tools we useNext.jsNode.jsExpressPostgreSQLPrismaStripeAWSSupabase

Questions

API design & integrations, answered.

Something else on your mind? Ask the Zelvorm Concierge in the corner, or talk to the team.

REST is simple and widely supported, and suits most public APIs. GraphQL can be useful when clients need flexible queries. We choose based on your consumers.