Software integration
Software integration
Many businesses use several software products: accounting, CRM, ecommerce, scheduling, email marketing, perhaps a custom application. When they do not talk to each other, staff re-type information, totals disagree and nobody is sure which system is right. Software integration connects these systems so that information flows automatically and consistently between them.
This page explains the main ways systems are connected and the decisions that make an integration dependable.
Illustrative diagram
Connected systems
- CRM
- Contacts
- Leads
- Ecommerce
- Products
- Orders
- Accounting
- Invoices
- Payments
- Operations
- Jobs
- Stock
Ways systems connect
| Method | How it works | Suits |
|---|---|---|
| API | One system requests or sends data through a defined interface | Many modern cloud products |
| Webhook | A system notifies another when something happens | Near-instant updates such as new orders |
| File exchange | Files exported and imported on a schedule | Older systems or batch processes |
| Integration platform | A service that links products with configured flows | Common products and simple rules |
| Shared database | Systems read the same data store | Tightly linked internal systems only |
Deciding which system is right
Before connecting anything, decide which system owns each kind of information. Customer contact details might belong to the CRM, prices to the ecommerce platform and invoices to accounting. Other systems receive copies but do not change the original, or send changes back through an agreed route. Without this, two systems can update the same record differently and overwrite each other.
A simple table listing each data type and its owner prevents much confusion.
Mapping data between systems
Identity
- How the same customer or product is recognised in each system
- Shared reference numbers stored on both sides
- Rules for matching when references are missing
Fields
- Which fields move and in which direction
- Format differences such as dates and currencies
- Lists that must match, such as tax codes or categories
Timing
- Instant, scheduled or on request
- What happens to changes made while offline
- Order in which records must arrive
Common integrations
Sales to accounting
Orders or invoices created in accounting automatically.
Website to CRM
Enquiries recorded as leads with their source.
Stock across channels
Inventory levels kept consistent between shop and warehouse.
Scheduling to billing
Completed jobs passed through for invoicing.
Integration platform or custom code
Integration platform
Suits you when
- Both products are supported by the platform
- Rules are simple
Watch out for
- Per-task or per-flow fees; complex logic gets awkward; check data handling
Custom integration
Suits you when
- Logic is complex or volumes are high
- One side is bespoke or unusual
Watch out for
- Needs hosting, monitoring and maintenance
Built-in connector
Suits you when
- One product offers a native connection to the other
Watch out for
- Check exactly what it syncs before relying on it
Planning an integration
Map the flow
What moves, from where to where, and when.
Output: Flow map
Check capabilities
Review each system's API, limits and connectors.
Output: Feasibility
Map fields
Field-by-field mapping with examples.
Output: Mapping table
Build and test
Run with test data and edge cases.
Output: Working integration
Monitor
Watch for failures after launch.
Output: Reliable flow
Respecting each system's limits
APIs usually limit how many requests can be made in a period, and some charge for higher usage. Bulk imports may be restricted to certain times. An integration that ignores these limits can fail at busy moments or be blocked. Checking each system's documentation for limits, and designing to work within them, avoids surprises when volumes grow.
One-way or two-way
One-way integrations, where data flows from an owning system to others, are simpler and more predictable. Two-way integrations, where changes in either system update the other, are sometimes necessary but need rules for conflicts: if a phone number is changed in both systems at once, which wins? Start with one-way flows where possible and add two-way synchronisation only where staff genuinely need to edit the same information in both places.
Many apparent needs for two-way sync disappear once the source of truth is agreed.
Security of connections
Integrations hold credentials that can read or change data in your systems. Store them securely, never in shared documents or code, and give each connection only the permissions it needs. Use separate credentials for each integration so one can be revoked without affecting others. Review connections periodically and remove those no longer used, along with their access.
Bringing historic data across
A new integration usually handles records from launch onwards. Decide separately whether existing records need a one-off import, and check that the two do not create duplicates.
Questions about software integration
What is software integration?
Connecting systems so information flows between them automatically and consistently.
What is an API?
A defined interface that lets one system request or send data to another.
What is a source of truth?
The system that owns a particular kind of information; others receive copies.
Should we use an integration platform?
For simple flows between supported products; custom code suits complex logic.
How are records matched between systems?
Using shared reference numbers, with rules for when they are missing.
Do APIs have limits?
Usually; integrations should be designed to work within request limits.
Should integrations be one-way or two-way?
One-way where possible; two-way only where staff must edit data in both systems.
Request a Custom Quote
Ask about Software integration
Thank you — your enquiry has been sent.
We have received your message and will reply by email. If you need to add anything, email info@letgetgrow.com.