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Exposys

Systems ยท APIs & Integrations

API development and integrations that just keep working.

We design APIs and build the integrations that move data between your products, payment providers, accounting packages and CRM. The aim is simple: fewer spreadsheets, no copy and paste, and connections that recover gracefully when something upstream fails.

Start a projectWhat we build

01Problems we solve

If this sounds familiar, we can help.

  • Data typed in twice

    Orders, invoices and contacts are re-keyed by hand between tools, which costs hours and invites mistakes.

  • Fragile point-to-point links

    A tangle of scripts and plugins breaks quietly whenever a vendor changes something, and nobody notices for days.

  • An API partners struggle to use

    Inconsistent endpoints and missing documentation turn every partner integration into a long email thread.

  • No single view of the truth

    Each system holds a slightly different version of the customer, so reports never quite agree.

02What we build

Clean APIs in, dependable connections out.

  • 01

    REST and GraphQL API design

    Consistent, versioned APIs with sensible resources, pagination, errors and authentication your developers and partners can rely on.

  • 02

    Payment integrations

    Checkout, subscriptions, refunds and payouts connected to providers such as Stripe or PayPal, with webhook handling that survives retries.

  • 03

    Accounting and finance connections

    Invoices, payments and customer records synced with packages such as Xero or QuickBooks, so finance stops chasing exports.

  • 04

    CRM and marketing sync

    Leads, deals and activity flowing between your website, product and CRM such as HubSpot or Salesforce without manual uploads.

  • 05

    Webhooks and middleware

    Event-driven services and queues that sit between systems, transform data and retry safely when an endpoint is down.

  • 06

    API documentation and developer portals

    OpenAPI specifications, examples and sandbox access that let a new developer make a first successful call quickly.

03Key capabilities

The craft behind every release.

  • REST and GraphQL API design
  • OpenAPI and schema-first development
  • OAuth 2.0 and API key authentication
  • Webhook receivers with idempotency
  • Queues, retries and dead-letter handling
  • Data mapping and transformation
  • Rate limiting and API versioning
  • Integration monitoring and alerting

Technology we use

  • Node.js
  • TypeScript
  • Python
  • GraphQL
  • OpenAPI
  • Postman
  • PostgreSQL
  • Redis
  • RabbitMQ
  • AWS Lambda
  • Stripe API
  • Docker

04How we work

A clear path from first call to handover.

  1. 1

    Map the systems

    We list every tool involved, who owns each piece of data and what should happen when records change.

  2. 2

    Design the contract

    Endpoints, payloads and error cases agreed in an OpenAPI or GraphQL schema before code is written.

  3. 3

    Build and test

    Integrations built against sandboxes, with automated tests for edge cases such as duplicates and timeouts.

  4. 4

    Launch and watch

    Staged rollout, logging and alerts, so failed syncs are caught and replayed rather than lost.

What you get

Concrete deliverables, agreed in writing before work starts.

  • Systems and data flow map
  • API specification in OpenAPI or GraphQL schema
  • Authentication and access model
  • API implementation with automated tests
  • Third-party integration services
  • Webhook handlers with retry logic
  • Field mapping and transformation rules
  • Error logging and alerting setup
  • Developer documentation and examples
  • Postman or similar request collection
  • Runbook for common failures
  • Handover session with your team

05Why Exposys

One senior team, accountable end to end.

  • Contract first

    We agree the API shape on paper before building, so front end, back end and partners can work in parallel.

  • Designed for failure

    Every integration assumes the other side will sometimes be slow or down, and handles it with retries and clear logs.

  • Secure by default

    Scoped credentials, secrets kept out of code and least-privilege access to every connected system.

  • Documented for the next developer

    Specs, runbooks and readable code mean your team, or anyone else, can maintain the work without us.

Who it's for.

  • SaaS products

    Public APIs, partner integrations and the webhooks customers expect from a modern product.

  • Ecommerce and retail

    Stores connected to payments, inventory, fulfilment and accounting without manual exports.

  • Professional services

    Practice, billing and CRM tools linked so client records stay consistent everywhere.

  • Finance operations

    Reliable movement of invoices, payments and reconciliation data between platforms.

06FAQ

APIs & Integrations questions.

Should our API be REST or GraphQL?

REST suits most public and partner APIs because it is simple to cache, document and consume. GraphQL can help when several front ends need flexible queries over related data. We recommend one based on who will use the API and explain the trade-offs.

Can you connect tools that do not have a ready-made integration?

Usually, yes. If both systems expose an API or webhooks we can build a direct connection, and where they do not we look at options such as scheduled file exchange. We confirm what is feasible after reviewing the vendors' documentation.

What happens when a third-party service goes down?

We design integrations to queue work, retry with sensible back-off and log anything that still fails. Alerts tell you about persistent problems, and failed events can be replayed once the service recovers.

Should we use a no-code tool like Zapier instead?

For simple, low-volume workflows a no-code tool is often the right answer and we will say so. Custom integrations make sense when you need complex logic, higher volumes, stronger error handling or tighter security.

Will we get documentation for the API?

Yes. Every API we build comes with an OpenAPI specification or GraphQL schema, worked examples and notes on authentication and errors, kept in your repository alongside the code.

All services

Start a project

Systems that will not talk to each other? Let us connect them.

Tell us what you are building. We will reply with clear next steps and honest advice, even if we are not the right fit.

contact@exposysglobal.com