Freelance Backend Developer

Transmission•,

1d•Remote

About The Position

Transmission is seeking an experienced freelance AWS Cloud and Backend Engineer to assess and strengthen the existing AWS infrastructure and backend architecture of its proprietary AI-powered marketing intelligence platform. The role focuses on improving security, stability, and scalability as user adoption grows, and contributing directly to Phase 2 development. This is an existing-application engagement rather than a greenfield project. The initial engagement is project-based, with potential for extension, and is remote. The engineer will review and improve AWS infrastructure and security, assess production readiness and performance, and develop backend functionality using Python and FastAPI. The role also supports data integrations, background processing, AI/LLM integration, collaboration with AI developers and data scientists, documentation, and technical knowledge transfer.

Requirements

At least 7 years of software engineering experience, including senior-level backend development.
Extensive hands-on experience managing and troubleshooting production AWS environments.
Strong Python and FastAPI development experience.
Demonstrated expertise with AWS ECS, Fargate, IAM, VPC networking, ALB, CloudWatch, Cognito, and S3.
Experience assessing cloud infrastructure security and remediating vulnerabilities.
Proven experience with application scalability, load testing, and production performance optimization.
Strong SQL and PostgreSQL experience.
Experience with Docker, CI/CD, GitHub Actions, and infrastructure as code.
Ability to independently review an existing technical architecture and implement improvements.

Nice To Haves

AWS Certified Solutions Architect – Professional, or equivalent demonstrated expertise.
AWS Certified DevOps Engineer – Professional.
AWS Certified Security – Specialty.
Experience with AWS CloudFormation.
Experience with Snowflake, Prefect, and asynchronous/background processing.
Experience with AI-powered applications and third-party LLM APIs.
Experience designing secure, multi-tenant SaaS applications.
Experience with security assessments, penetration-test remediation, and production launch readiness.
Experience taking an application from early development into secure, scalable production use.
Comfort working with a small team of AI developers and data scientists.

Responsibilities

Review AWS staging and production architecture, configurations, and deployments.
Assess ECS/Fargate, networking, application load balancing, IAM, Cognito, S3, KMS, and Secrets Manager.
Evaluate environment isolation, permissions, authentication, authorization, and data security.
Identify vulnerabilities, misconfigurations, security gaps, and infrastructure risks; recommend and implement remediation, prioritizing critical issues before broader production rollout.
Review AWS CloudFormation configurations and infrastructure deployment practices.
Evaluate readiness for increased concurrent users and application workloads.
Assess API performance, database connections, application resource utilization, and scaling configurations.
Conduct or support load and stress testing to identify performance bottlenecks.
Review application logging, CloudWatch monitoring, alerting, and incident-response capabilities.
Evaluate backup, recovery, resilience, and deployment/rollback processes.
Ensure staging environments adequately represent production behavior.
Develop and improve backend functionality using Python and FastAPI.
Troubleshoot and optimize REST APIs and third-party integrations.
Support PostgreSQL, Snowflake, and AWS-hosted data integrations.
Develop reliable background processing, scheduled jobs, and asynchronous workflows.
Support integration of AI/LLM services with the existing application.
Collaborate with the AI developer and data scientists to complete Phase 2 functionality.
Document changes and provide technical knowledge transfer.