HRTech // Client Project

Global Payroll:
40 Regions, One Reliable View.

We built a practical HRTech solution combining regional adapter system, event-sourced reconciliation, and traceable audit logs. The project delivered 40+ Regions Unified and 92% Manual Load Removed.

Key Results RESULTS
40+
Regions Unified
GLOBAL SCALE
92%
Manual Load Removed
ROI: 14 Weeks
Zero
Regulatory Penalties
Traceable Data

Trusted by teams building ambitious products

What We Set Out to Improve.

Industry
HRTech

SaaS provider managing payroll for 15,000+ employees across 40 different tax jurisdictions.

How We Worked
Project-Based Delivery

Platform Architect + 3 Backend Engineers + DevOps Lead assigned to deliver the custom engine against defined milestones.

Goal
Global Day-to-day Growth

Replacing a disconnected network of local providers with a single, auditable automatic platform.

What We Built
Smaller independent services Platform

A practical solution designed around the client’s existing tools, teams, and day-to-day workflow.

What Was Getting in the Way.

The client relied on 14 different local payroll vendors and hundreds of manual spreadsheets to manage global operations. This Inconsistent Data made it impossible to get a live view of total labor costs and introduced high risks of regional tax filing errors.

The biggest issues were regulatory exposure, wasted time and cost, and growth blocker. The team needed a faster, clearer way to manage the work while keeping the right checks in place.

Regulatory Exposure
Inconsistent localized tax calculations led to a $200k+ audit penalty in the prior fiscal year.
Wasted Time and Cost
The HR team spent 60% of their month on manual reconciliation instead of higher-value hiring.
Growth Blocker
Opening a new region took 3 months of vendor negotiation and API mapping, halting market expansion.
The Solution

What We Built.

01
Regional Adapter System
Designed a Plug-and-Play adapter layer that isolates localized tax logic from the core payroll ledger.
Key details
Type Modular Adapters
Isolation Smaller independent services
Standard ISO20022 Aligned
02
Event-Sourced Reconciliation
Used Automatic record updates to maintain a 100% accreate Timeline of Truth for every salary change and tax adjustment.
Key details
Pattern Event Sourcing
Stream Live data service Native
Consistency Transactional
03
Traceable Audit Logs
Every payroll run generates a cryptograpatient health informationcally hashed audit trail containing all regional policy versions applied.
Key details
Log Type Traceable Data
Security SOC2 Ready
Trail Secure and traceable
Before and After

How the Workflow Improved.

Area
Before
After
New Region Onboarding

12-16 Weeks

Manual vendor vetting, legal contracts, and custom API integration per country.

3 Weeks

Configuring a new Regional Adapter service using pre-built Coretus compliance templates.

Compliance Logic

External/Manual

Relying on vendor portals. No visibility into calculation logic until errors occurred.

Internal/Governed

Shared rule engine with Reason Codes for every local tax deduction.

Data Freshness

Batch/Monthly

Global cost reports were 30 days out of date due to regional provider lag.

Live Streaming

Global payroll accruals update instantly as changes happen in the HRIS.

Key Features

What Made the Solution Useful.

Live Updates

Saga Pattern Automation

Managed distributed transactions across regional databases to ensure zero ghost-pay or missing bank file events.

Business impact
100% Payment Integrity
AI Assisted

Automated Anomaly Detection

AI assistants flag regional tax variations and payroll outliers before the run is finalized, preventing overpayments.

Business impact
↑ 4.2% Margin Saved
Faster Delivery

How We Reduced Build Time.

Tested foundations helped the team spend less time on setup and more time on the parts that made this product useful.

What accelerated the work

4 reusable building blocks
01

Compliance Auth Module

A tested starting point for compliance auth module reduced repeated setup work.

02

Regional Adapter Module

Reusable work for regional adapter module let the team focus more time on the client’s specific needs.

03

Global Ledger Monitoring

This made it easier to add global ledger monitoring without rebuilding common foundations.

04

Forex Safety controls

A tested starting point for forex safety controls reduced repeated setup work.

Results

The Business Difference.

A straightforward before-and-after view of what changed for the team and their customers.

RESULT: AGILITY01

Regional Onboarding Speed

Automated adapter deployment allowed the company to hire in new countries almost instantly.

Old Way90 Days
Unified Platform21 Days
Outcome4x Faster Market Entry
RESULT: OPS EFFICIENCY02

Payroll Admin Overhead

Removing manual spreadsheet reconciliations freed up the HR team for valuable talent work.

ManualHigh
AutomatedMinimal
Outcome92% Time Savings
RESULT: RELIABILITY03

Tax Filing Accuracy

Shared controls eliminated human error in regional localized filings.

ErrorsFrequent
PenaltiesZero
Outcome100% Less Compliance Verified
Results4x Faster Market Entry • 92% Time Savings
Trust and Control

How We Kept It Safe and Reliable.

01
Data Privacy (GDPR)
Cloud-based regional database sharding ensures employee data stays within the required legal territory.
Ready to Grow
02
Security System design
Field-level encryption and OIDC-based scoped access meet the strictest SOC2 payroll standards.
Business SECURE
03
Scale Readiness
Distributed modular cloud system design handles 50,000+ concurrent payslip generations with zero lag.
ZERO DOWNTIME
04
Code and IP Ownership
Through the Project-Based model, Coretus delivered the full source, workflows, documentation, and knowledge handover to the internal engineering team.
100% OWNED
Client Testimonial

In their own words.

Coretus didn't just build a payroll platform, they built a borderless Compliance Platform . We unified 40 regions into one source of truth, eliminated all manual reconciliation, and reclaimed months of team productivity.

Scale Globally with Accuracy.

Have a similar challenge? We can help you plan and build a practical HRTech solution around your goals, budget, and existing systems.

SOC2 & GDPR Gated

Regional Sharding System design

Complete Project IP Handover