Enterprise Integration Developer – ERP / Billing Systems (Contract) (£450 pd outside IR35) at SourceWise Solutions, Remote, £450 per day

Enterprise Integration Developer – ERP / Billing Systems (Contract)

SourceWise is looking for an experienced, hands-on Enterprise Integration Developer to support a major technology client building integrations between modern APIs and enterprise ERP and billing platforms.

The role will focus on designing and delivering production-grade connectors between external APIs and platforms such as Workday, Salesforce, Microsoft Dynamics, Zuora or similar enterprise systems.

We are looking for someone who has personally built, deployed and supported enterprise integrations, rather than someone whose experience is primarily functional configuration, implementation consulting or advisory work.

What you’ll be doing

• Design and build integrations between enterprise ERP/billing platforms and external APIs.
• Develop native applications, extensions, plugins or workflow automations within your specialist enterprise platform.
• Trigger integrations from business events such as invoices, customers, suppliers and orders.
• Map enterprise data objects to external API models.
• Build secure integrations using REST and/or SOAP APIs.
• Implement authentication using technologies such as OAuth 2.0, WS-Security or equivalent.
• Build reliable error handling, retry and failure-management mechanisms.
• Handle API failures, timeouts, duplicate requests and partial processing.
• Design asynchronous integrations using webhooks, polling or event-driven approaches.
• Account for API rate limits, idempotency and versioning.
• Test integrations end-to-end and support production readiness.
• Document architecture, configuration and operational processes.
• Work closely with product and software engineers to define API contracts and integration patterns.

What we’re looking for

You should have strong hands-on development experience with at least one enterprise ERP or billing platform.

Relevant backgrounds could include:

Workday
Workday Extend, Workday APIs, Workday Orchestration or related development/integration technologies.

Salesforce
Apex, Flow, platform events, APIs or custom Salesforce integration development.

Microsoft Dynamics
Dynamics 365 plugins, Power Platform, Dataverse, APIs or workflow development.

Zuora
Zuora APIs, billing workflows, platform extensions or integration development.

Experience with other comparable enterprise ERP, finance or billing platforms will also be considered.

You should also have:

• Strong practical experience with REST and/or SOAP APIs.
• Experience integrating enterprise applications with third-party SaaS platforms.
• Understanding of authentication and secure API communication.
• Experience with data mapping and enterprise business objects.
• Strong knowledge of error handling, retries, idempotency and API versioning.
• Experience with asynchronous integrations, including webhooks and/or polling.
• Good understanding of API rate limits and resilient integration design.
• Experience building and supporting production integrations.
• Ability to work independently and investigate platform capabilities where requirements are not fully defined.

Enterprise finance experience

A good understanding of enterprise finance workflows is important for this role.

Ideally, you will have experience with:

• Order-to-Cash (O2C)
• Procure-to-Pay (P2P)
• Customer invoicing
• Supplier invoicing
• Orders
• Customer and supplier master data
• Understanding where external applications integrate into financial business processes.

The ideal candidate

This opportunity would suit a hands-on integration engineer or developer who enjoys building rather than simply advising.

You should be comfortable taking responsibility across:

Solution design → Development → Integration → Testing → Production readiness → Documentation

You will work closely with enterprise-system specialists as well as engineers working on modern API and cloud platforms.

Wider technology environment

The wider engineering environment includes:

Backend: Go / Node.js
Frontend: React / TypeScript
Database: PostgreSQL
Cloud: Azure / GCP
Infrastructure: Kubernetes

You do not need to be an expert in this entire technology stack. Your primary value will be deep expertise in your chosen enterprise ERP/billing platform and its integration capabilities.

Engagement

Contract

This is a delivery-focused engagement. We are looking for someone who can become productive quickly and contribute directly to implementation.

About SourceWise

SourceWise connects specialist technology professionals with organisations building and scaling modern digital products and platforms.

For this engagement, you will work closely with an experienced product engineering team on a strategically important enterprise integration initiative.

Apply

Please apply with your latest CV and clearly highlight:

Enterprise ERP/Billing platform expertise | REST/SOAP APIs | Third-party integrations | OAuth / authentication | O2C / P2P | Asynchronous integrations | Webhooks / polling | Error handling | Production integration delivery

Pay: Up to £450.00 per day

Work Location: Hybrid remote in London