Lead Integration Architect (Python/AWS/Shopify Migration/MCP)

NO AGENCIES. INDEPENDENT FREELANCERS ONLY. READ THIS FIRST: This is a hands-on lead role. You will spend roughly half your time writing production Python code. If you have spent the last few years in diagrams, meetings and Jira while others wrote the code, this role is not for you, and the screening process will surface that quickly. You will lead a team of 3-4 senior engineers and own the technical architecture across the migration: AWS microservices, POS and OMS integrations, third-party SaaS connections, and a new layer of MCP servers exposing vendor APIs to AI agents. This is a long-term, full-time engagement. It is not a short advisory gig. Key Responsibilities: - Write production Python code weekly alongside the team you lead - Design the integration architecture for the Shopify migration: what gets rebuilt, what gets rewired, in what sequence relative to the SFCC decommission - Set API standards, authentication patterns, and error handling and monitoring conventions for the whole team - Define the security model for MCP servers: how vendor APIs are scoped, authenticated and audited when exposed to AI agents - Build reusable integration services and frameworks - Review all significant designs and pull requests - Run sprint-level technical planning - Lead daily communication with client engineering leadership - Sequence and de-risk the production cutover, including rollback planning Requirements: - 8+ years of backend and integration engineering, with 2+ years leading or mentoring engineers - Strong Python in production (will be tested during screening) - Deep AWS architecture experience: designing, deploying and operating production microservices - Track record of owning a platform migration or large integration program end to end - REST and GraphQL API design; OAuth and enterprise authentication patterns - Docker, CI/CD and infrastructure automation - Clear client-facing communication; able to present tradeoffs to non-engineers - Fluent English - Minimum 4 hours daily overlap with US Eastern time, full-time availability Nice to Have: - Shopify or Salesforce Commerce Cloud ecosystem experience - MCP server development or AI agent tooling - BigQuery or comparable data warehouse experience - Retail or ecommerce domain background: POS, OMS, order and inventory flows