Top Senior Software Engineer Jobs in St. Louis, MO

Leads technical strategy and architecture for a scalable advertising platform supporting video, server-side advertising, connected TV, programmatic advertising, and new ad formats. Designs distributed systems, evaluates ad technologies, improves reliability and observability, partners across engineering and product teams, mentors engineers, and guides long-term technical investments and roadmaps.

Develop scalable test automation frameworks, QA tools, and intelligent testing systems using Playwright, C#, and JavaScript/TypeScript. Integrate automated testing into CI/CD pipelines, build end-to-end, integration, and performance solutions, and apply AI techniques to improve test generation and defect detection. Partner with engineering and QA teams, troubleshoot reliability issues, contribute to test strategy, and mentor colleagues on automation and modern testing practices.

Develop cross-platform C++ and Qt software for network device discovery, monitoring, and data collection across Windows and Linux. Build high-performance, concurrent, asynchronous systems that communicate with thousands of devices using SNMP, SSH, ICMP, WMI, and related protocols. Own testing, troubleshoot issues across application, operating-system, and network layers, optimize reliability and performance, and collaborate with backend, UI, QA, and product teams.

Build and evolve low-latency, high-throughput news delivery services using Java and Python. Own architecture, feature delivery, performance, observability, production support, and technical direction. Collaborate within a scrum team, automate deployment and maintenance using DevOps practices, and participate in a sustainable on-call rotation. Apply real-time systems, cloud infrastructure, container orchestration, search technology, testing, and news data standards to deliver reliable services globally.

Staff Software Engineer responsible for designing scalable distributed systems and full-stack web applications supporting provider acquisition, onboarding, and marketplace supply growth. The role leads cross-team technical initiatives, shapes engineering strategy, mentors developers, and delivers provider-facing products from discovery through post-launch support. Experience with AI-assisted development workflows and technologies such as Node.js, React, TypeScript, Kafka, AWS, Docker, and Kubernetes is valued.

Build and maintain scalable full-stack web applications using PHP, Laravel, React, Next.js, SQL, and related technologies. Own features from design through deployment and monitoring, develop APIs, optimize databases and legacy systems, troubleshoot performance issues, and contribute to code quality, security, and engineering practices. Collaborate cross-functionally in an agile, continuous-deployment environment while using AI-assisted tools responsibly.

Build and lead development of high-availability backend services for Affirm’s card loan platform. Design scalable APIs, data models, microservices, and event-driven systems supporting real-time loan attribution, approvals, origination, and refunds. Drive technical strategy, troubleshoot complex performance issues, collaborate with cross-functional teams, and mentor engineers while ensuring long-term system robustness and scalability.

Own Headway’s cloud platform and infrastructure engineering strategy. Lead deployment isolation, container orchestration, AWS networking and compute, autoscaling, capacity planning, Terraform self-service infrastructure, cloud cost attribution, and Python runtime performance. Build reliable paved-road tooling that enables engineering teams to deploy safely and independently while improving scalability, observability, and operational resilience.

Lead end-to-end development of modern frontend initiatives using React and Electron. Design scalable architecture, improve performance and test coverage, resolve production issues, influence technical decisions, and collaborate with Product, Design, and Backend teams. The role includes mentoring engineers, maintaining code quality, supporting observability and incident response, and building secure, high-quality customer-facing payment and form workflows.

Build enterprise control-plane products for managing Hightouch deployments at scale. Responsibilities include developing roles, permissions, and access control; creating change-management tools for evolving data models and warehouses; and helping customers understand and optimize warehouse performance and costs. The role requires backend and distributed-systems architecture, asynchronous workflows, scalability, reliability, product thinking, and engagement with product specifications.

Design, build, and optimize distributed systems powering large-scale data synchronization. Responsibilities include improving sync speed, developing real-time streaming capabilities, scaling high-volume and low-latency systems, troubleshooting customer scaling challenges, and supporting multi-region, multi-cloud infrastructure and data residency requirements. The role involves end-to-end project ownership, customer collaboration, system architecture, and reliability improvements.

Design and evolve scalable referral, partner data, and patient booking systems. Lead complex technical projects across teams, make architecture and API decisions, improve security, performance, reliability, and scalability, and mentor engineers. Collaborate with product, design, engineering leadership, partners, and stakeholders while using AI-assisted development tools such as Claude Code to improve delivery velocity and quality.

Designs and develops cloud-based and on-premises data and integration solutions for payer operations. Responsibilities include architecting integrations across SaaS, Epic EMR, and enterprise data platforms; coding, testing, debugging, and performance optimization; troubleshooting data issues; collaborating with product and business stakeholders; incorporating AI/ML; and maintaining architecture documentation, governance, and best practices.

Leads architecture, full-stack development, scalable application design, dashboards, backend integrations, AI-enabled features, cloud infrastructure, DevOps, monitoring, and production support. Mentors engineering teams, establishes technical standards, guides strategy, and develops solutions for payer operations, metadata, contracts, and performance measurement.

Design and build Seeq’s internal platform, including infrastructure, services, multi-tenant Kubernetes clusters, system interfaces, and secure deployment capabilities. Improve scalability, reliability, software delivery, and infrastructure cost and performance. Lead migrations, integrate security practices, architect distributed systems, collaborate cross-functionally, and mentor engineers while remaining hands-on at Staff or Principal scope.

Build and ship Ori developer tools across CLI, Slack, desktop, and cloud surfaces. Develop multi-model agent runtimes with model switching, provider fallbacks, tool integrations, sandboxing, secrets management, session handling, and version-controlled agent state. Own the full product experience, including installation, authentication, reliability, observability, and evaluations. Collaborate with product, design, and platform teams while feeding platform requirements into OpenRouter APIs and SDKs.

Build and operate Numeral’s public API, MCP server, billing and ERP integrations, infrastructure, data pipelines, and platform services. Own projects from design through production, improve observability and reliability, automate deployment workflows, and contribute to architecture decisions. The role requires strong backend engineering, distributed systems knowledge, cloud and container experience, and a customer-focused approach to dependable financial automation.

Build and scale AI-enabled developer experience systems, including CI/CD platforms, deployment safeguards, observability, automated response workflows, and multi-agent orchestration. Reduce developer toil and technical debt while improving software delivery speed, safety, reliability, and production quality. Partner with engineering teams to adopt AI-native delivery practices and convert emerging capabilities into scalable internal platforms.

Build and operate Numeral’s platform services, public API, MCP server, ERP and billing integrations, infrastructure, data pipelines, and developer interfaces. Own projects from technical design through production, improve observability and reliability, automate deployment workflows, and support scalable background jobs and APIs. Collaborate with product and engineering teams while applying distributed-systems principles and maintaining accurate, dependable financial-data workflows.

Lead the technical vision, architecture, and delivery of Toast’s pricing engine across multiple teams. Design and operate highly available distributed systems, APIs, databases, and event-driven services at scale. Serve as the pricing domain expert, improve correctness and performance, lead incident response and reliability initiatives, mentor engineers, establish operational excellence, and align technical priorities with Product and engineering leadership.

Lead backend engineering strategy for Affirm’s search and recommendation platform. Design and launch highly available distributed systems, guide technical architecture and execution, improve team operations and reliability, establish engineering quality standards, collaborate with product, design, and analytics, and mentor engineers. The role focuses on search, recommendations, consumer shopping experiences, monetization, and scalable platform foundations.

Architect, build, and operate large-scale relational and distributed SQL database infrastructure. Responsibilities include database control-plane automation, provisioning, failover, backups, upgrades, zero-downtime migrations, Kubernetes networking, connection proxy optimization, reliability monitoring, capacity planning, and operational support. The role also leads technical delivery, mentors engineers, establishes quality standards, collaborates cross-functionally, and contributes to team roadmap and on-call operations.

Design and build scalable frontend and backend features for route planning, routing, navigation, and route execution products. Partner with product, design, and engineering leadership to improve planner efficiency, leverage AI appropriately, and promote technical excellence. Mentor junior engineers, contribute to team growth, engage with customers, and help scale products across industries and customer verticals.

Leads full-stack software engineering and technical delivery for enterprise applications across the Microsoft .NET and Azure ecosystem. Designs scalable architectures, APIs, integrations, distributed and event-driven systems, and cloud-native solutions. Provides hands-on development, code reviews, troubleshooting, DevOps collaboration, CI/CD, production support, and operational improvement. Mentors engineers, coordinates technical delivery, manages risks and dependencies, and partners with Product, Architecture, Security, QA, and infrastructure teams.

Build and scale a telemedicine platform using React, TypeScript, Python, Flask, and PostgreSQL. Own features through development, deployment, and launch; develop integrations; write tests; conduct design and code reviews; resolve production issues; and collaborate with Product, Design, and Quality teams in a Scrum environment. The role also involves mentoring engineers, improving development processes, and communicating technical decisions to nontechnical stakeholders.