Senior Software Engineer (Java Full Stack / AWS)
Job Description
OperAxis is hiring a Senior Software Engineer for a leading payments and financial services organization in O'Fallon, MO. You'll join a platform engineering team with a startup mindset, building and operating cloud-native services for premium card products across frontend, backend, cloud and AI-native engineering on AWS. The ideal candidate is a hands-on full stack engineer who can independently build, deploy, troubleshoot and demonstrate end-to-end solutions. The role is hybrid, so candidates located near O'Fallon, MO are preferred. Duration: 7 months, contract Requirements • Senior-level full stack development experience • Frontend: Angular and/or React • Backend: Java and/or Golang • Cloud and platform: AWS, Kubernetes and cloud-native technologies • Hands-on experience building and deploying microservices on AWS (ECS with Fargate preferred) • Ability to troubleshoot complex integrations across mobile front ends, backend microservices and AWS • Nice to have: Python FastAPI, CloudFormation or Terraform, Amazon Bedrock and AgentCore • Bachelor's degree or equivalent experience
Responsibilities
- Build scalable, domain-driven microservices using Golang and Python FastAPI
- Integrate backend APIs with mobile SDKs to establish a reliable orchestration layer
- Deploy and operate cloud-native services on AWS ECS, Fargate and ARM64 on AWS Graviton
- Provision and automate infrastructure using CloudFormation and Terraform
- Build and integrate AI-native capabilities using Amazon Bedrock and AgentCore Runtime
- Troubleshoot end to end across mobile, backend, cloud infrastructure and AI runtime layers
- Deliver rapid proofs of concept and prototypes alongside engineers from an acquired startup
- Independently build, deploy, run and demonstrate solutions to internal and external stakeholders
- Contribute to a cloud-native payment orchestration platform for cardholder digital services