When organizations decide how to synchronize data between applications, one of their top considerations is whether the data should sync in one direction or both.

To help you understand when you should implement a one-way synchronization versus a two-way, or bidirectional synchronization, we’ll define the former, highlight its use cases, benefits, and more. 

What is one-way synchronization?

It’s the process of transferring data from a source application to a target application without any feedback or data modification from the target. This ensures that the target application is an exact copy—or a selective copy—of the source application.

Related: Definition of two-way API integration

One-way vs two-way synchronization

The key difference lies in the flow of data. For one-way syncs, the data flow is linear—from the source to the target; while in bidirectional syncs, data flows in both directions. 

In the case of bidirectional syncs, both the source and target can send and receive data, making it a mutual exchange. This method is more dynamic and is used in applications where real-time data collaboration is necessary.

While two-way synchronization offers more flexibility, it also introduces complexities, such as conflict resolution and data integrity challenges. One-way synchronization, being simpler, reduces these complexities but at the cost of reduced interactivity and dynamism.

Examples of one-way synchronization

Let’s review a few internal one-way synchronization use cases and a few that are customer-facing.

Add candidates who sign their offer letter to your HRIS

Once a candidate signs your offer letter, your team will want to move quickly in adding them to your HRIS (among other applications). It’s only then that the larger HR team can be made aware of the incoming hire and go on to take the appropriate pre-boarding steps, such as ordering the incoming hire equipment (e.g. a laptop), assigning them access to specific applications, organizing their desk, etc.

To help HR find incoming hires in your HRIS on time, you can integrate your ATS with your HRIS and build a one-way sync where once a candidate is marked as hired in the former, they’re automatically added as an employee in the latter. 

You can also sync specific employee fields between the applications, such as an employee’s full name, job title, address, hiring manager, etc. so that HR has all the context they need to complete their pre-boarding tasks.

Share new leads with reps on your business communications platform

As your marketing team generates new leads, it can be easy for sales to miss them. After all, they’re likely busy out-bounding and having conversations with a variety of other accounts. 

To prevent any leads from slipping through the cracks, you can integrate your CRM with your business communications platform (e.g. Slack) and build a one-way sync where any time a a lead is added to the former, it’s shared in the latter. 

Moreover, key information on the lead, such as their full name, job title, employer, Linkedin profile, the content they downloaded, etc. can be included in the message—giving the rep enough information to perform follow-up research and respond to the lead quickly.  

Enable organizations to source candidates with ease

Say you provide a recruitment automation solution that recommends candidates for certain roles and allows clients to either accept or reject those recommendations.

To make the recommended candidates easier to find (especially for any recruiters who don’t have access to your application) and follow-up with once a client accepts them, you can integrate your product with clients’ ATS solutions. You can then build a one-way sync where, if a client approves a candidate in your product, the candidate would go on to get added in the client’s ATS.

Specific fields associated with the client can be synced over in the candidate’s ATS profile, such as their full name, current employer, current job title, any notes generated or added in your product, etc. This should help your recruiting team follow-up with the candidate quickly and thoughtfully.

Auto-provision users and update them in your product seamlessly

Regardless of the product you offer, your users will need to be able to add and remove colleagues from it with relative ease. Any potential friction in the process can prevent clients from adding users (which can stymie product adoption) and removing them on time, if at all (which opens the client up to all kinds of risks). 

Similarly, as specific users’ roles change, whether it’s through a promotion or a switch to a different department, the information should be reflected in your application with little delay—as it can potentially change their level of permissions in your product.

To accommodate the scenarios above effectively at scale, you can connect your product with clients’ HRIS solutions and build a couple one-way syncs between the two. More specifically, any time a user is added or removed from a client’s HRIS solution, that employee is added or removed as a user in your product. Similarly, if specific employee fields change in the client’s HRIS solution, the changes will also take effect in your product.

Related: Top examples of data synchronization

Benefits of one-way synchronization

Here’s a look at how one-way syncs can help your business:

Enhanced data integrity

Since data flows in only one direction, the risk of the source data being altered or corrupted is significantly reduced. This is crucial in maintaining the integrity of the original data, especially in backup and archival systems.

Simplified data management

One-way synchronization simplifies data management as it eliminates the need for conflict resolution and complex synchronization logic required in two-way systems. This simplicity makes it easier to implement and maintain.

Security

In scenarios where data security is paramount, one-way synchronization offers an added layer of security. Since the data can’t be altered or sent back from the target to the source, it safeguards the source data against unauthorized changes or security breaches.

Consistency and reliability

This synchronization method ensures that all target systems or databases have consistent and up-to-date information as per the source. It provides a reliable method of data dissemination without the worry of discrepancies.

Cost-effective

For many applications, one-way synchronization offers a cost-effective solution. It requires less computational resources and infrastructure compared to two-way synchronization, making it a viable option for small to medium-sized businesses.

Supports large-scale deployments

In large-scale deployments, like CDNs or massive data backup solutions, one-way synchronization ensures efficient and consistent data distribution across multiple nodes or locations.

Build one-way syncs between your product and clients’ apps with Merge

Merge, the leading unified API platform, lets you offer a whole category of customer-facing integrations by building to a single unified API. 

The platform also offers management tooling, maintenance support, webhooks, and much more to ensure that you’re able to build high-performing and reliable integrations over time.

You can learn more about Merge by scheduling a demo with one of our integration experts.