Senior Backend Engineer (IAM, Node.js, Python, API Security & Consumption Systems)
Senior Backend Engineer (IAM, Node.js, Python, API Security & Consumption Systems) Title: Senior Backend Engineer – IAM, Node.js, Python, API Security, Multi-Tenant SaaS (Urgent) Job Type: Freelance / Remote Experience Required: 4–10 Years Location Preference: India Remote About the Role We are seeking a highly skilled Senior Backend Engineer with strong expertise in IAM, Node.js, Python performance optimization, API Security, and multi-tenant usage/consumption tracking systems. This is a critical production stabilization role that directly impacts system performance, reliability, and revenue integrity across multiple SaaS products. Context Our platform runs a centralized Identity & Access Management (IAM) system powering multiple applications, including: WhatsApp Chatbot AI Support & Automation Platforms Email Campaign Engine LinkedIn Posting & Automation Admin Dashboards & Analytics Two major production issues need urgent resolution: Major Challenges to Solve 1. Python Performance Failure (High Severity) IAM permission and consumption logic in Python has degraded API performance to ~30 seconds per request in production Impacts chatbot responses, campaign execution & AI inference Needs deep performance debugging & async optimization 2. API Consumption Tracking Failure (Prod Only) Usage tracking works in Dev, fails only in Production API hit metrics, package/module usage & token tracking not recorded Likely related to gateway/middleware/caching/environment issues Key Responsibilities -Diagnose and fix Python performance bottlenecks to achieve sub-second latency -Resolve Production-only consumption & billing tracking issues -Ensure reliable IAM permission enforcement across Node.js services -Strengthen multi-tenant architecture and quota enforcement -Build audit-grade logs for usage tracking & billing compliance -Improve caching strategy, route protection, and wildcard permission logic -Work with AI, billing & frontend teams for system alignment -Required Technical Skills Must Have Strong Node.js (Express.js / NestJS) Strong Python (AsyncIO / FastAPI / Flask / Performance optimization) IAM Models (RBAC/ABAC/PBAC) Multi-tenant SaaS understanding API Gateways, Middleware, Rate Limiting Debugging across Dev/QA/Prod environments API Security, JWT, OAuth Good to Have Redis cache & throttling Kafka / Event streaming Elasticsearch / Distributed logging AI token consumption systems Metered billing architecture What Success Looks Like (60–90 Days) Sub-second response time for IAM-based Python services Production usage tracking fully restored Accurate billing/consumption at module & artifact level Consistent IAM permission enforcement across services Zero Dev–Prod mismatches Complete audit logging & tenant usage integrity Why Work With Us High-impact engineering challenge Direct influence on platform stability & revenue Long-term collaboration potential Fast-decision hiring process How to Apply Please include: Resume / Portfolio Examples of similar performance optimization or IAM projects Apply tot his job