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Backend Engineer · Paismo · 2025

Paismo: Nexus API & HRMS backend

A multi-tenant HRMS backend and public workforce API covering payroll, time & attendance, leave, and document generation, with bi-directional accounting sync.

Node.js · NestJS · PostgreSQL · Unified.to · Nx monorepo

0domain modulestenant-isolated
0req / minNexus API rate limit
0AWS regionspayroll deploy
FIG.01Paismo: system at a glance
API & AUTH EDGECORENEXUS APIpublic · key + secret1,000/min · Helmet · auditAUTHAuth0 · JWKS-RSA (JWT)CASL (RBAC + ABAC) · tenant isoNestJS CORENx monorepoPostgreSQL+ read replicasHRMS MODULES · 77 entitiesPayrollAttendanceLeaveDocumentsReportingPAYROLL · asyncSQSqueueLambdaDockerized · ×2 regionsWebSocketpayroll statusDOCUMENTSPuppeteerPDF payslipsINTEGRATIONSSynapseNestJS syncUnified.toQuickBooks / XeroStripewebhooksLaunchDarklyfeature flagsOBSERVABILITYOpenTelemetryauto-instrumentationPrometheus + Jaegermetrics · traces

External systems call the Nexus API, a NestJS service in an Nx monorepo, which reads and writes tenant-isolated data in PostgreSQL. The API is organized into modules for payroll, attendance, leave, and document generation. A separate sync service moves data bi-directionally between PostgreSQL and QuickBooks and Xero through Unified.to.