Custom Factorial integration development
Appfront builds custom Factorial integrations that connect your HR administration with your own software, payroll system or wider HR stack. Using Factorial's REST API and webhooks, we synchronise employees, leave, absence and time tracking reliably and in the right direction. You keep one source of truth for your people data and save your HR team hours of manual re-entry.
What is a Factorial integration?
Factorial is an HRIS (HR Information System) for small and mid-sized businesses, scale-ups and service organisations. It brings leave and absence, time tracking, onboarding, document management, payroll preparation and recruitment (ATS) together in one platform. For many HR teams, Factorial is therefore the central record for everything relating to people.
In practice, a custom integration means synchronising employee data between Factorial and your own application, passing leave and absence data on to a scheduling tool, delivering time tracking to a payroll provider, and responding in real time via webhooks whenever something changes in Factorial. This way you avoid duplicate data entry and keep one reliable source for your people data.
Appfront builds in line with the official Factorial API documentation and the OWASP ASVS security standard. We align data flows, scopes and error handling with your actual HR processes, so the integration grows with your organisation and keeps running reliably, including during busy periods such as onboarding new employees.
Central people administration
Employees, contracts, leave and documents in one place in Factorial. An integration keeps this data automatically in line with your own systems, so a change only has to be made once.
Insight into leave & time registration
Leave balances, absence and hours worked flow via the API to your planning, reporting or payroll preparation. Your team works with up-to-date figures instead of scattered exports and manual overviews.
Two-way sync
Factorial webhooks notify your systems immediately when an employee is created, requests leave or a contract changes. Your applications stay in real time without polling or manual updates.
Our development process for Factorial integrations
We work to a proven methodology that removes uncertainty early and delivers a stable integration. From an initial analysis of your HR processes, the modules to connect and the systems involved, through to go-live and ongoing management, every step is aimed at an integration your team can understand and trust.
We map out which Factorial modules you want to connect (employees, leave, time tracking, payroll), which direction data should flow in, and which systems on your side are involved.
We design the integration architecture, choose between API key or OAuth2 with appropriate scopes, and set up an error handling and retry strategy.
Implementation with automated tests, structured logging and monitoring. You see working builds along the way.
Controlled go-live with data validation and a safety net, followed by ongoing management and further development.
What a Factorial integration concretely delivers
Every Factorial integration is tailored to your HR processes, the chosen modules and adjacent systems. Below are the features we most often deliver for organisations that use Factorial as the core of their HR administration.
REST API and OAuth2 integration
A stable connection to Factorial's REST API, authenticated via API key or OAuth2 with scoped permissions. We work with the dated API versions so your integration stays reliable when Factorial rolls out changes.
Employee & employee sync
Synchronise employees, teams and contract details between Factorial and your own application, identity provider or intranet. A new or departing employee only needs to be recorded in one place and is instantly updated everywhere.
Leave & absence
Retrieve or forward leave requests, balances and absence records to your planning and reporting systems. Approvals in Factorial can trigger a follow-up action in your own system via webhooks.
Time tracking
Connect clock-in and clock-out events and worked hours from Factorial to scheduling, project administration or time recording. This way recorded hours link seamlessly to your invoicing or payroll preparation.
Supplying payroll data
Supply the data needed for the payroll run — contracted hours, changes, leave and absence — in a structured way to your payroll provider. Less manual work around payroll processing and fewer chances for typing errors.
Webhooks & events
Real-time webhook subscriptions for events such as a new employee, a submitted leave request or a clock-in. Failed deliveries are retried neatly; persistent failures disable the subscription, so you spot discrepancies quickly.
Typical use cases in practice
A Factorial integration looks very different from one organisation to another. We see a number of patterns recur often, and for each we have a working setup with attention to the right modules, sync direction and scopes.
HR teams in small and medium-sized businesses
SMEs that use Factorial as their central HR administration and want to connect it to their own software or intranet. Employees, contracts and leave stay automatically in line, so HR doesn't have to enter anything twice. See also our API integrations.
Fast-growing scale-ups
Scale-ups that hire quickly and want to streamline onboarding. A new employee in Factorial automatically triggers accounts, access and tasks in your own systems via webhooks — so someone can get to work on day one.
Service providers & agencies
Agencies and consultancies that work on an hourly basis and want to connect time tracking from Factorial to project and time administration. Worked hours and leave link seamlessly to scheduling and invoicing, without separate exports between systems.
Retail & hospitality with rotas
Retail and hospitality organisations with shifting rotas and many part-time staff. Connect clock-in/clock-out and leave data from Factorial to scheduling and payroll preparation, so recorded hours and balances always match the actual deployment of staff.
Technology we use
We build Factorial integrations using the official REST API and webhooks, combined with the backend stack that suits you. The exact choice depends on the modules to be integrated and your existing systems, so your own team can manage or further develop the implementation.
Why choose Appfront for your Factorial integration?
Appfront has extensive experience building API integrations for a wide range of organisations in the Netherlands. We always start with a thorough analysis of your existing systems and HR processes. An integration should not only work technically, but also add practical value to the way you work.
For every integration, we write clear documentation and make sure your own team, or any future supplier, can understand and manage it. No black box, just transparent code and clear agreements on monitoring, alerting and maintenance.
You work with a dedicated point of contact who understands both the technical and the functional side. This keeps communication short, prevents misunderstandings and speeds up decisions when choices need to be made during development.
See also our wider services around API integrations, middleware, custom software development and web app development.
- Experience with the Factorial REST API, webhooks and OAuth2
- Specialist in HR integrations: employees, leave, time tracking and payroll
- Experienced with two-way sync and webhook-driven workflows
- Secure by default — token rotation, webhook signature validation, scoped permissions
- Structured error handling and retry mechanisms
- Comprehensive logging and monitoring from day one
- Clear documentation your team can read and manage
- A fixed point of contact, no account managers passed around
- Ongoing maintenance and proactive further development
- A way of working aligned with your existing IT landscape
Security and privacy for Factorial integrations
A Factorial integration almost always processes personal employee data (PII): names, contracts, leave, absence and hours worked. By definition, this is highly sensitive data. Appfront builds to the OWASP ASVS. That means, among other things: API keys and OAuth2 tokens held in secure vaults, webhook signature validation, scoped permissions and regular audits of the data flows.
With personnel data, data minimisation is the starting point: we only integrate the fields the integration genuinely needs and limit the OAuth2 scopes accordingly. We document the data flows between Factorial and your systems, so your record of processing activities is complete and you can demonstrate compliance with the GDPR. Clear agreements on retention periods and access are, in our view, a standard part of that.
More on our security approach: information security policy and CVD policy.
- GDPR-compliant data processing and data minimisation
- Encryption in transit (TLS 1.2+) and at rest
- Role-based access and least-privilege principles
- Audit logs with traceable data flows
- Automatic retries and dead-letter queues
- Monitoring and alerting for anomalies
- Secrets management in line with best practice
- Documentation for your record of processing activities
Frequently asked questions about Factorial integrations
Answers to the questions we are asked most often about Factorial integrations.
A Factorial integration is a technical link between Factorial and another system, such as your own application, payroll system, scheduling tool or HR stack. Through Factorial's REST API, employee data, leave and absence data, time tracking and documents are exchanged programmatically. Webhooks deliver real-time updates whenever something changes in Factorial. An integration can be simple (synchronising employees to one system) or extensive (two-way sync of leave, time tracking and payroll data across multiple systems).
Factorial is an HRIS (HR information system) aimed at SMEs, scale-ups and service organisations. It suits teams that want to manage leave and absence, time tracking, onboarding, documents and payroll preparation in one place. If you want Factorial to work with your own software, payroll provider or scheduling tool, a custom integration via the API is the right route. In an intake session, we will work with you to establish whether Factorial fits your processes and which modules you want to integrate.
A simple integration, such as one-way synchronisation of employees or retrieving leave requests, can go live within a few weeks. More complex scenarios, such as two-way sync of time tracking and payroll data, documents and webhook-driven workflows across multiple systems, generally take longer. After an intake session in which we map out the data flows and modules, we will give you a realistic estimate.
We work with Factorial's official REST API and webhooks, combined with the backend stack that suits you: Node.js, Python, PHP, .NET, Ruby or Go. Authentication runs via an API key or OAuth2, with scopes limited to what the integration genuinely needs. For version management, we use Factorial's dated API versions, so your integration remains stable when Factorial introduces changes.
The cost is determined by the complexity of the data flows, the number of systems to connect, the desired direction and frequency of synchronisation, and the amount of custom business logic. Ongoing maintenance, monitoring and support also affect the total investment. We always provide a clear quote following a no-obligation analysis of your situation.
Yes. A Factorial integration handles employee data, so privacy is central by definition. Appfront builds to the OWASP ASVS: API keys and OAuth2 tokens are kept in secure vaults, webhook signatures are validated, permissions are scoped, and rights are strictly separated per integration. We only process the data that is necessary (data minimisation) and document the data flows so your record of processing activities stays complete and you can demonstrate GDPR compliance.
Yes. Appfront regularly takes over existing integrations, even those originally set up by another party. We review the API integration, webhook configuration, scopes and error handling, document the current setup and propose improvements. From that point on, we handle changes, extensions and monitoring, including timely rotation of API keys and tokens.
Factorial suits HR teams at SMEs, fast-growing scale-ups and service organisations that want to manage leave, absence, time tracking, onboarding and documents in one place. Typical integrations include syncing employees with your own application or identity system, passing leave and time-tracking data to a planning tool, and supplying payroll data to a payroll provider. For highly specific enterprise HR processes, we will work with you to establish whether Factorial is the right foundation.
Ready to build your Factorial integration?
Tell us which Factorial modules you want to connect and which systems they need to link to. We are happy to advise on employee sync, leave, time tracking, payroll and webhooks. A no-obligation first conversation will give you a clear picture of what is possible within half an hour.