Lead Backend Engineer - Python

***This position is onsite in Jacksonville and available on a W2 basis only. ***

***C2C, 1099, THIRD-PARTY REPRESENTATION, AND CURRENT OR FUTURE SPONSORSHIP ARE UNAVAILABLE.***

Lead Backend Engineer, Python & Event Sourcing

Location: Jacksonville, FL, onsite

Employment: W2 contract through CSI Companies

Estimated pay: $52–$67/hour W2, depending on experience

CSI Companies is seeking a hands-on Lead Backend Engineer to help build the core of a live operational platform. You’ll write production software, guide a small team of specialists, and own the quality, security, and delivery of your work.

This role calls for someone who has designed and built event-driven systems, including event sourcing or CQRS, and can explain the decisions behind systems they personally delivered. The work centers on backend services and transaction processing.

What you’ll do

• Design and develop backend components in Python for a secure, event-driven platform.
• Apply event sourcing, CQRS, and domain modeling to operational workflows.
• Make practical build-versus-configuration decisions within the platform’s architecture.
• Enforce tenant isolation in server-side services and protect data across events, databases, and object storage.
• Work with relational databases and read models or projections.
• Build with serverless compute, object storage, containers, and local cloud emulation.
• Set a meaningful test bar for unit and integration tests, security boundaries, and CI checks.
• Use AI-assisted development tools while carefully reviewing generated code and tests for correctness and security.
• Guide a small engineering team, communicate progress and risks clearly, and take ownership of delivery.

What we’re looking for

• 8+ years of hands-on software engineering experience, including recent production development.
• Strong Python skills and experience designing event-driven systems with event sourcing, CQRS, or closely related patterns.
• Experience securing multi-tenant or multi-party applications, including server-side authorization and encryption in transit and at rest.
• Working knowledge of relational SQL and projection or read-model design.
• Experience with cloud-native, serverless development, object storage, containers, and automated testing.
• Sound technical judgment and the ability to explain what you built, how you secured it, and how you verified that it works.
• Experience leading delivery while remaining actively involved in the code.

Experience with configuration-driven platforms, streaming systems, secrets management, federated CI credentials, or container orchestration is helpful.

This position is onsite in Jacksonville and available on a W2 basis only. C2C, 1099, third-party representation, and current or future sponsorship are unavailable.