Top Software Engineer Jobs in St. Louis, MO

Develops and leads software design, coding, testing, integration, requirements traceability, code reviews, verification, and deployment for Boeing Phantom Works solutions. The role collaborates with stakeholders, resolves technical risks, evaluates team and supplier performance, and mentors junior engineers. Work involves Java or C++, MATLAB, DevSecOps tools, Agile development, and complex space-based mission applications. An active Top Secret clearance and U.S. person status are required.

Paid, full-time software engineering internship supporting customer-context data patterns, decision-engineering tools, requirements analysis, and data-platform products. Interns collaborate with department teams, participate in professional development, networking, mentorship, and cross-functional activities. Candidates must be rising seniors pursuing a bachelor’s degree, maintain at least a 3.0 GPA, and be authorized to work in the U.S. without current or future employment-based sponsorship.

Participate in a 10-week software engineering internship developing, testing, and deploying scalable enterprise applications. Interns collaborate in Agile teams, build APIs and microservices, support cloud and data engineering initiatives, and use approved AI-assisted development tools. Responsibilities include writing tests, reviewing AI-generated code, contributing to architecture and platform work, applying secure SDLC practices, and exploring AI/ML integrations while following regulatory and confidentiality requirements.

Lead cross-functional teams to design, build, and deliver scalable enterprise software and products. Own engagement relationships, product roadmaps, architecture (APIs, microservices), CI/CD and quality practices, project planning, and mentoring of junior staff to drive delivery and continuous improvement.

Provides technical leadership for enterprise full-stack applications and microservices using React, Node.js, .NET, and Azure. Leads legacy-platform modernization, cloud migration, data integration, messaging, SQL and Delta Lake architecture, AI-powered automation, frontend UI migration, security compliance, and technical debt reduction. Mentors cross-functional engineering teams and guides platform innovation.

As a Software Engineer in Frontier AI Infrastructure, you'll design secure systems for the public sector, improve engineering standards, and collaborate with cross-functional teams to meet government requirements. You'll also participate in customer engagements and contribute to the product strategy while ensuring compliance with federal regulations.

Build backend-focused Java/Kotlin APIs and data-driven product features, while contributing to React dashboards and workflows. Design scalable systems, participate in architecture and code reviews, troubleshoot production issues using observability tools, and collaborate with data, reporting, design, and product teams to launch emerging products.

Lead development of scalable Java backend applications and high-availability cloud services. Design architectures, REST APIs, databases, caching systems, and distributed session infrastructure. Mentor engineers, drive technical initiatives, address performance and scalability challenges, and uphold quality and automation practices for endpoint management products.

Develop and architect a cross-platform C++ endpoint patching agent for Windows, macOS, and Linux. Responsibilities include code reviews, mentoring engineers, improving development processes, collaborating across patching teams, and translating product needs into resilient technical designs. The role involves system-level APIs, patch installation and rollback logic, embedded databases, and client-server integration.

Own the design and implementation of native iOS and Android SDKs supporting mobile device intelligence and fraud detection. Investigate complex systems-level engineering problems, evaluate platform behavior and technical tradeoffs, collaborate with Product, Engineering, Data Science, Fraud Intelligence, and Sales, and establish SentiLink’s mobile engineering capabilities.

Manages the Marketplace Performance software engineering team, setting technical strategy and delivering business-critical backend and consumer marketplace systems. Partners with product, design, analytics, revenue, and merchant teams; oversees system reliability, monitoring, testing, on-call operations, and technical standards. Develops engineering talent, drives quality and ownership, and contributes to Affirm’s ads platform and marketplace monetization initiatives.

Lead backend engineering strategy for Affirm’s international Identity team. Design and launch highly available distributed systems supporting KYC, user lifecycle management, and identity decisioning. Drive technical planning, cross-functional collaboration, operational excellence, monitoring, testing, and on-call readiness. Establish engineering quality standards, influence architecture, mentor team members, and deliver scalable systems using Python or Kotlin, AWS, MySQL, Spark, and Kubernetes.

Senior Software Engineer responsible for designing, developing, testing, and releasing scalable full-stack features for Huntress’s Core Platform. The role owns complex projects end to end across frontend, backend, databases, and infrastructure; promotes code quality through testing, reviews, and pairing; breaks down epics into milestones; contributes technical solutions; and mentors engineers. The position requires extensive Ruby on Rails and full-stack experience, plus familiarity with Linux infrastructure, databases, external APIs, Agile practices, and responsible AI-assisted development.