Top Software Engineer Jobs in St. Louis, MO

Lead architectural modernization of enterprise .NET applications into cloud-native microservices. Define technical strategy, cloud architecture (AWS/GCP), DevSecOps/CI-CD, mentor engineers, drive API-first and front-end modernization, and align technology with business goals.

Paid, full-time software engineering internship supporting customer-context data patterns, decision-engineering tools, requirements analysis, and data-platform product development. Interns spend approximately 80% of their time on department projects and 20% on professional development, networking, mentorship, community service, and presentations. The role runs for 11 weeks during summer 2027.

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.

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.

Develop and enhance Toast’s website-building platform and related AI-powered digital growth products. Design, scope, and implement full-stack solutions using modern web technologies, improve performance and scalability, collaborate with Product and Design, run experiments, resolve critical issues, and write clean, testable code. The role contributes to API design, unit and integration testing, agile delivery, and cross-team product integration.

Develop and scale full-stack software that calculates and delivers restaurant employee pay, including tip pooling, wage calculations, earnings retrieval, and payroll delivery. Responsibilities include designing reliable services, participating in code reviews and architecture discussions, influencing technical roadmaps, and collaborating with product, design, and engineering teams. The role requires backend development, modern web technologies, databases, distributed systems, messaging, microservices, and a strong focus on precision and production reliability.

Build and scale mission-critical tips, earnings, and payroll platforms for restaurant employees. Own systems end to end, lead complex projects from design through deployment, improve reliability and correctness, collaborate with product and design, review code, mentor engineers, and deliver scalable backend services that affect employee pay and product revenue.

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.

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.