Top Senior Software Engineer Jobs in St. Louis, MO

Lead full-stack growth engineering across eligibility, identity, access, client configuration, and reporting systems. Build Python-based GraphQL and REST APIs, React and React Native experiences, scalable database systems, and secure HIPAA- and GDPR-compliant solutions. Own ambiguous cross-domain technical projects, write RFCs, coordinate roadmap delivery, mentor engineers, contribute to engineering strategy, and participate in on-call operations and remediation.

Build and operate accessible, high-performance member-facing web applications using a front-end-first full-stack approach. Contribute to APIs, backend services, data flows, integrations, frontend architecture, testing, observability, and performance improvements. Own projects from concept through production, collaborate with Product, Design, Data, and Clinical teams, improve developer experience, support AI-assisted coding practices, participate in technical reviews and incident follow-up, and mentor engineers.

Develop and maintain software in an agile, test-driven environment using pair programming. Lead technical decisions involving application and data model design, mentor engineers, collaborate cross-functionally with product and design, and ensure application stability and performance. Participate in on-call support and improve system reliability. Use AI developer tools to accelerate development and improve code quality.

The Software Engineer will scale and optimize the platform's infrastructure, manage data layers, and enhance system operations to support growing LLM requests.

As a Software Engineer at OnePay, you will develop and implement features, build scalable products, and work closely with teams to enhance customer experiences.

Develop and optimize distributed systems for syncing customer data, focus on scalability, reliability, and performance for global clients.

Build and evolve scalable backend systems and APIs for a large SaaS platform. Partner with Product, Design, and QA from ideation through deployment, contribute to microservices architecture, improve testing and observability, identify operational risks, and mentor teammates. The role emphasizes reliable, maintainable solutions, strong collaboration, architectural decision-making, and continuous improvement.

Design, architect, develop, test, and support scalable full-stack applications for a high-volume, multi-tenant data platform. Own features from design through delivery, contribute to technical strategy and roadmap development, ensure operational excellence, collaborate across distributed teams, and mentor engineers. Apply cloud-native technologies and AI-assisted development practices while supporting near-real-time analytics and reliable production operations.

Build and operate Yahoo’s developer experience platform, including CI/CD infrastructure, artifact repositories, release pipelines, and ArgoCD GitOps deployments. Develop reusable golden-path workflows, AI-assisted automation, configuration validation, and platform tooling. Support pipeline troubleshooting, artifact management, runner optimization, observability, security practices, and developer adoption through migrations, documentation, office hours, and technical enablement.

Lead architecture and delivery across Rails backends and React frontends, build Node.js and NestJS platform integrations, establish testing and code-quality standards, mentor engineers, review code, and improve reliability, performance, and developer experience. The role requires technical ownership across multiple backend technologies and leadership in AI-assisted development practices.

Design, build, and operate scalable, highly concurrent backend services in Go. Architect distributed, fault-tolerant systems, optimize performance and reliability, define APIs and service boundaries, improve observability and operational readiness, and collaborate cross-functionally to support mission-critical autonomous deployments.

Design and build cloud cost-management capabilities, including forecasting, anomaly alerts, cost allocation, data pipelines, transformation models, visualizations, and reusable UI components. Own features end to end from planning through release while improving application reliability and performance. Collaborate closely with engineers and founding team members, contribute to technical design and roadmap decisions, and work pragmatically in a fast-moving distributed startup environment.

Design, implement, and support high-performance storage and query infrastructure handling billions of events. Independently scope and deliver complex projects, optimize query performance, improve reliability, participate in on-call rotations, define KPIs and SLOs, reduce operational toil, debug production issues, collaborate cross-functionally, and mentor engineers.

Develop open source SDKs, enterprise APIs, UIs, and backend systems supporting large-scale computer vision datasets. Build scalable, maintainable, performant, and well-tested software for unstructured data and AI workflows. Contribute to enterprise deployments across customer clouds and on-premises environments, while improving tooling, automation, engineering practices, and open source community initiatives in a remote-first team.

The Staff SDET will design and implement automated test frameworks using TypeScript, collaborate with developers, and enhance testing processes within CI/CD pipelines.

Design, implement, and maintain scalable Java-based software solutions. Collaborate across the SDLC with stakeholders and development teams, integrate DevOps and CI/CD practices, support operational tasks, ensure security and performance, drive feature development, conduct code reviews, and stay current with emerging technologies.

Technical leader for Platform & Infrastructure building scalable, resilient cloud-native systems to support large AI workloads. Define architecture, mentor engineers, solve systemic infrastructure bottlenecks, design foundational platform services, and collaborate cross-functionally to ensure secure, high-performance operations.

Lead architecture and scaling of cloud-native infrastructure to support large AI workloads. Mentor engineers, decompose complex systems, design foundational platform services, and collaborate with product, research, and security teams to ensure secure, performant, and highly available GPU/ML infrastructure.

Build and maintain end-to-end web applications powering sales and operations. Design tools for quoting, scheduling, and fulfillment, integrate AI into products, collaborate on UX, ship high-impact features, and contribute to architecture, deployment, and engineering culture.

The Software Engineer will build features across the stack, design AI/LLM-driven workflows, translate requirements, and collaborate closely with the founding team and customers.

The Senior Full-Stack Software Engineer will design, build, and scale backend services and APIs for financial transactions while collaborating with frontend engineers and contributing to technical design.

As a Senior Backend Developer, you'll design and maintain high-volume pipelines and databases, implement ETLs for automated abuse-prevention, and develop monitoring solutions while collaborating with teams on safety systems.

As a Senior Fullstack Developer, you will build and maintain moderation and user-safety applications for Bluesky's Trust & Safety team, collaborating with product teams and improving tools based on user feedback.

The Staff Engineer will lead the Systems team, design scalable cloud infrastructure, optimize data pipelines, and ensure platform reliability and security.

As a Senior Software Engineer, you will design and implement AI technologies to address complex logistics challenges and mentor team members.