Merge, Kombo and Finch are unified API products optimized for HR tech startups reading employee data from common HR systems. Their architecture flattens payroll data into a canonical schema, has structural coverage gaps for country-specific local providers, and loses the audit trail required for retro records and YTD accumulators. datascalehr is a vendor-agnostic connectivity layer optimized for bidirectional global payroll integration with full field fidelity, lossless data flow, and 150+ country coverage.