Senior Backend Engineer - SQL, Security, Payments & Platform Architecture

NENN is seeking a Senior Backend Engineer to lead the stabilization, security hardening, and production readiness of an AI-assisted MVP PIMS platform. This system is being actively built with AI-generated components and requires an experienced engineer who can identify hidden risks in code, database design, and integrations, then systematically transform it into a secure, scalable, and reliable production platform. A core requirement of this role is advanced SQL expertise, including the ability to review and correct AI-generated database structures and queries. In addition, this role will own security architecture, data governance, and Stripe payment integration. The goal is to prepare the platform for public demonstration and trade show readiness by December.

Core Responsibilities

Architecture Ownership & System Stabilization

• Audit current MVP architecture (backend, database, APIs, hosting)
• Identify structural weaknesses introduced by AI-generated code
• Define a scalable backend architecture (services, data flows, boundaries)
• Reduce technical debt and enforce maintainable patterns
• Establish environment strategy (dev / staging / production)

SQL & Data Layer Ownership (Required Core Skill)

• Design and normalize relational database schemas (PostgreSQL or equivalent)
• Review and correct AI-generated SQL code and schema design
• Optimize queries, indexing strategies, and execution plans
• Identify data integrity issues (duplication, inconsistency, race conditions)
• Implement audit trails and data lineage where needed
• Establish backup, restore, and disaster recovery processes

Security & Risk Mitigation (Critical)

• Perform full application security assessment (OWASP-aligned)
• Identify vulnerabilities in:
• Authentication & session management
• API endpoints
• Database access patterns
• Third-party integrations
• Implement:
• Role-based access control (RBAC)
• Encryption at rest and in transit
• Secure secrets management
• Define logging, monitoring, and breach detection strategies
• Ensure data privacy and compliance readiness (as applicable)

Payments & Stripe Integration (Required)

• Architect and implement secure Stripe integration for:
• Subscriptions (if applicable)
• One-time payments
• Invoicing and billing workflows
• Ensure PCI-safe design (no sensitive card data stored)
• Handle webhook validation and idempotency correctly
• Design payment state tracking in the database
• Prevent double-charging, race conditions, and webhook spoofing
• Build reconciliation and payment audit mechanisms

API & Integration Layer

• Build and maintain RESTful APIs (or equivalent architecture)
• Evaluate third-party APIs for reliability and failure modes
• Implement robust error handling and retry logic
• Ensure system resilience under partial outages

AI- Generated Code Governance (Key Requirement)

• Review AI-generated backend and SQL code for correctness and safety
• Identify hallucinated logic patterns, unsafe queries, or broken assumptions
• Refactor AI-generated code into production-grade standards
• Establish coding standards for future AI-assisted development

Do you have experience in Systems integration?, * 5+ years backend engineering experience

• Expert-level SQL (mandatory)
• Strong experience with PostgreSQL/MySQL or equivalent
• Proven ability to review and repair AI-generated codebases
• Deep understanding of backend security principles
• Experience with Stripe or equivalent payment systems
• Strong API design and integration experience
• Experience with system architecture and scaling applications
• Familiarity with cloud infrastructure (AWS, GCP, or Azure)

Preferred Qualifications

• Experience with AI-assisted development environments
• Experience in SaaS or operational logistics platforms
• React familiarity (not required)
• Experience in healthcare, veterinary, logistics, emergency response, or field operations systems
• DevOps / CI/CD experience.

$150,000 - $200,000 a year - Full-time