Senior Software Architect

About the Role

We are seeking a Senior Full-Stack Engineer to lead the architecture and development of a multi-tenant SaaS platform serving regulated financial and government procurement workflows. You will own end-to-end product surfaces — from configurable admin panels and tenant-aware data models to fee calculation engines, payment lifecycle tracking, and audit-ready financial exports. This role suits a seasoned builder who has previously been the lead or sole developer on a non-trivial SaaS platform and is comfortable making architecture decisions across the stack.

This is a W-2 full-time employment position with Cincinnatus LLC, with the opportunity to be placed at a leading client as part of their extended workforce.

Key Responsibilities

• Own architecture decisions across frontend, backend, data, and infrastructure for a multi-tenant SaaS product; balance configurability with maintainability.
• Build admin-managed configuration for fee models, reporting periods, grace periods, escalation rules, branding, and integrations — without requiring code changes per tenant.
• Design and maintain role-based access control across distinct user populations (internal ops, external vendors, government customers) with separate permission matrices per portal.
• Build and maintain fee calculation engines supporting percentage, flat, capped, and tiered models with deterministic rounding; deliver audit-ready exports at penny-level precision.
• Implement payment lifecycle tracking, cash reconciliation, and exception handling against external payment systems.
• Integrate payment processors, procurement ERPs, CRM systems, and notification services into a cohesive platform; work with government payment gateways where applicable.
• Partner with product, ops, and compliance stakeholders to translate regulatory and contractual requirements into shippable software.

Core Qualifications

• 5+ years of professional full-stack engineering experience , with 2+ years as a lead or sole developer owning architecture decisions on a production SaaS product.
• Has built multi-tenant SaaS with tenant-level configurability — fee models, reporting periods, grace periods, escalation rules, branding, and integrations all manageable by admins without code changes.
• Has built role-based access control spanning internal operators, external vendors, and end customers, with separate permission matrices per portal.
• Has worked on financial or transactional features — billing, fee calculation, payments, or reconciliation. Penny-level precision and audit trails are the goal.
• Has integrated multiple third-party services into a single product.
• Strong written and verbal communication skills; able to drive technical decisions independently and document tradeoffs clearly.

Preferred Qualifications

• Experience building platforms serving government procurement or regulated financial compliance .
• Familiarity with government payment gateways (Tyler / NIC or similar).
• BI embedding experience (PowerBI, Jaspersoft, or similar) with row-level data isolation across tenants.
• Experience exposing platform functionality to an agent layer through a typed SDK or API (no AI/ML expertise required — the portal interfaces with the agent layer, it does not build it).

About Cincinnatus LLC

Cincinnatus LLC is an enterprise staffing company that partners with leading technology companies to source and employ highly skilled professionals for contingent and contract-based opportunities. Cincinnatus serves as the employer of record for these engagements, providing W-2 employment, payroll, benefits, and compliance, while placing employees directly within client teams to work on high-impact initiatives.

Roles hired through Cincinnatus are not project-based or freelance engagements. They are structured, role-based positions that typically involve part-time or full-time commitments, close collaboration with a client's internal teams, and integration into standard enterprise workflows.

Cincinnatus is a legal entity separate from Mercor. While opportunities may be discovered through Mercor's platform, employment, onboarding, payroll, and benefits for these roles are administered by Cincinnatus LLC.

Equal Employment Opportunity

Cincinnatus is proud to be an Equal Employment Opportunity employer. We do not discriminate based upon race, religion, color, national origin, sex (including pregnancy, childbirth, reproductive health decisions, or related medical conditions), sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, genetic information, political views or activity, or any other legally protected characteristic.

Cincinnatus is committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans throughout the job application process.