Top Senior Software Engineer Jobs in St. Louis, MO

Design, build, and operate Kubernetes-based compute orchestration and developer tooling. Deliver new compute capabilities, automate operations and observability, integrate AI into workflows, and partner with Security and Reliability to ensure platform scalability, performance, and incident response.

As a Full Stack Software Engineer, you will develop and maintain robust backend systems using Ruby on Rails, collaborating with cross-functional teams to enhance the real estate platform's performance and user experience.

The Senior Software Engineer will design and optimize recommendation algorithms, maintain data pipelines, and improve personalized user experiences using machine learning techniques and backend engineering skills.

The role involves designing and expanding backend systems, mentoring engineers, and executing technical strategies to modernize architecture and improve system performance.

As a Senior Software Engineer, you will build and integrate marketing technology stacks, lead technical projects, collaborate with cross-functional teams, and foster a high-performing engineering culture.

The Senior Software Engineer will build user features using Golang and cloud technologies, lead tool implementation, and collaborate across teams to enhance productivity.

Build and scale full-stack customer and agent support experiences across React/TypeScript frontends and Go backend services. Own APIs, integrations, and AI/ML vendor integrations, drive CX outcomes through experimentation and metrics, improve reliability through on-call incident response, and collaborate with Product, Design, and Ops to deliver measurable product outcomes.

Design, build, and operate scalable, secure data platform infrastructure for ingesting, processing, cataloging, and accessing petabytes of data. Improve Spark/Databricks reliability and developer experience, build ingestion/replication systems, develop internal libraries and tooling (Go/Python), and collaborate with cross-functional teams to support analytics, ML, and customer-facing data products.

Lead architecture and technical direction for Payments platform, building scalable, fault-tolerant distributed systems, defining roadmaps, ownership of production reliability, cross-functional partnership, and mentoring engineers to improve platform quality and scalability.

The role involves owning the architecture and technical direction of Payment Rails infrastructure, designing high-reliability systems for global payment processing, and leading cross-functional collaborations to create efficient, compliant solutions. Responsibilities also include mentoring team members and enhancing operational excellence through AI-driven improvements.

Lead the design and implementation of core authentication infrastructure at Phantom, focusing on secure authentication systems, secrets management, and API integrations.

As a Software Engineer, you'll develop trading APIs and systems, enhance user experiences, and lead initiatives for blockchain support and new products.

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

Join Aleph's engineering team to develop the Core Product, focusing on user-facing features for financial data insights. Collaborate with leadership, design robust software components, and contribute to system architecture in a fast-paced, remote environment.

As a Backend Software Engineer, you'll design, develop, and optimize scalable backend platforms and services while collaborating with cross-functional teams.

Develop and improve real-time drone tele-operations features, cloud-based products, and quickly prototype new front-end experiences while transitioning to a new tech stack.

Develop and deploy life-saving technologies as a fullstack engineer, focusing on web applications for public safety, collaborating with various engineering disciplines and leveraging customer feedback.

Design and implement high-performance system software for medical devices, collaborating with hardware engineers and ensuring adherence to clinical standards.

The Principal Desktop UI Software Engineer will design and develop user-friendly interfaces for medical devices, collaborating with cross-functional teams and mentoring junior members.

As a Senior Software Engineer, you will build backend APIs for authentication and authorization, partner with leadership, and mentor other engineers while improving production quality.

This role involves building and maintaining production-grade web applications using React and Next.js and developing cross-platform mobile features with React Native, while mentoring others and influencing technical direction.

As a Senior Software Engineer, you'll develop AI-powered tools, manage complex databases, optimize application performance, and lead technical decisions.

The Senior Software Engineer will design, develop, test, and maintain software for the Tomahawk Missile program, implement automation processes, and ensure compliance with safety standards and regulations.

Build and improve frontend experiences for login, signup, OAuth, account security, and multi-user/org support. Contribute to migrating main views to React Native, design high-performance React/TypeScript UIs, collaborate with backend engineers and product teams, and write well-tested, reliable code to maintain low-latency user surfaces at scale.

Lead architecture and delivery of Control Center platform capabilities (MCP tool registries, AI orchestration, access automation). Design agentic AI integrations, HITL workflows, and evaluation/guardrail frameworks. Own backend services, SLOs, observability, incident response, and operational readiness for Tier-1 systems. Drive cross-team technical direction, author TDDs, run design reviews, mentor engineers, and partner with Product and Security to deliver secure, scalable platform primitives.