Top Senior Software Engineer Jobs in St. Louis, MO

Build Tailscale’s internal AI-enablement tools, workflows, guardrails, and documentation. Partner with engineering leadership and teams to define the AI roadmap, evaluate coding agents and models, improve adoption, and measure effects on velocity and quality. The role involves developing internal developer-facing automation, teaching and influencing engineers, identifying high-leverage AI opportunities, and promoting safe use of AI-generated code in a distributed engineering organization.

Lead end-to-end development of reliable care-agent tooling and software services integrating contact-center platforms with backend systems. Own architecture, performance, security, production operations, and technical direction while partnering with product, care operations, QA, and engineering teams. Translate operational workflows into scalable solutions, mentor engineers, and improve tools using agent feedback, operational metrics, and AI-assisted development practices.

Lead technical vision and strategy for Affirm’s Cards backend engineering organization. Architect scalable and reliable platforms, guide cross-team initiatives, champion AI adoption and engineering excellence, influence technical roadmaps, and mentor engineers through Staff level. The role requires strong architectural expertise, organizational leadership, project management, communication, and cross-functional collaboration.

Develop and debug production-grade full-stack applications across front-end and back-end systems. Build features, APIs, databases, and data models; troubleshoot end-to-end issues; analyze unfamiliar codebases; translate implementations across programming languages; and review AI-generated and developer-written code for correctness, security, scalability, performance, and maintainability.

Lead technical execution and architecture for the Loyalty product. Own roadmap, design distributed services and APIs, ensure reliability/observability, integrate with ZMP and AthenaOS, build and coach engineering teams, and drive cross-team delivery of scalable multi-tenant loyalty capabilities.

Own and deliver backend lakehouse infrastructure goals, lead engineers through complex problems, and build highly available distributed data systems. Collaborate with product, design, analytics, and engineering stakeholders; define scalable technical solutions; improve code quality and engineering standards; monitor operational health; support on-call responsibilities; and mentor team members.

Design and scale foundational APIs and backend services for LogicGate’s multi-tenant GRC platform. Build distributed systems using Java/Kotlin, Spring Boot, AWS, databases, caching, and messaging technologies. Improve reliability, observability, performance, testing, and CI/CD practices. Lead technical design reviews, collaborate cross-functionally, mentor engineers, and use AI coding tools to improve development efficiency.

Set technical direction for Toast’s Developer Experience platform, including local development, build tooling, shared libraries, testing frameworks, and developer portals. The role combines hands-on software engineering with architecture, cross-team technical leadership, AI-assisted development, developer productivity measurement, mentorship, and roadmap prioritization.

Develop firmware, backend systems, and tooling for cellular IoT devices. Responsibilities include C development for STM32 microcontrollers, embedded AI integration, cellular communication, low-power optimization, device debugging and validation, and backend development with Python and Ruby on Rails. The role collaborates with hardware, electronics, and manufacturing teams and requires independently leading complex development initiatives.

Builds and maintains custom software applications using .NET, Java, and JavaScript technologies. Responsibilities include software design, coding, debugging, testing, troubleshooting, and developing web-based and client-server systems. The role handles complex technical projects autonomously, may provide technical consultation and team leadership, and requires strong collaboration and communication skills. Travel up to 15% is expected.

Builds and maintains custom software applications, performing design, coding, debugging, testing, troubleshooting, and technical consultation. Works autonomously on advanced projects, may lead work groups, and follows coding standards and technical designs. The role supports web-based and client-server systems and requires strong collaboration and communication. Up to 15% travel is expected.

Senior backend engineer responsible for designing and implementing new features, scaling and optimizing the platform, improving Postgres and Elasticsearch performance, fine-tuning LLMs, and making architectural decisions. Collaborate with engineering team, take ownership of features, write performant, maintainable code, and help shape product and infrastructure for data-intensive applications (NLP, search, indexing).

Develop and lead frontend platform engineering for native and hybrid mobile applications. Build reusable, well-tested Android and iOS SDK components, contribute to architecture and system design, collaborate with product and engineering teams, own customer-facing deliverables, and identify product improvements while maintaining strong engineering standards.

Senior frontend engineer responsible for developing and maintaining full-stack consumer-facing products. Owns features from design through implementation, testing, deployment, and bug resolution. Collaborates with product, UX, and business stakeholders; conducts code reviews; improves engineering processes, productivity, and code quality; documents workflows; estimates work; and mentors junior engineers. Requires expertise in React/Next.js, ORM and API development, Storybook, cloud technologies, and scalable always-available applications.

Design and develop highly available, fault-tolerant distributed edge computing platforms using Go, Kubernetes, microservices, and cloud technologies. Build scalable APIs, troubleshoot complex systems, conduct code reviews, optimize performance and security, collaborate cross-functionally, mentor engineers, contribute to planning, and maintain technical documentation.

Develop and maintain scalable SaaS solutions for financial reporting and capital markets customers. Responsibilities include full-stack development, system design, testing, monitoring, performance optimization, security, technical debt reduction, and collaboration with product managers, developers, and SRE teams. The role requires building reliable, secure, maintainable data-driven applications and contributing across the software development lifecycle.

Lead architecture and engineering for a new Provider Onboarding team. Build scalable, database-backed systems and custom tools supporting pricing, payments, client panels, and forms. Establish engineering practices, mentor senior engineers, guide cross-functional delivery, and oversee the full software development lifecycle from planning through post-launch maintenance. The role requires healthcare systems experience and ownership of complex, reliable products.

Lead architecture and development for a new Provider Onboarding engineering domain. Build scalable full-stack, database-backed applications and microservices supporting pricing, payments, client panels, forms, and provider workflows. Mentor engineers, establish design patterns, drive cross-functional delivery across the full software lifecycle, and improve operational reliability for a healthcare platform.

Lead the technical direction of Samsara’s shared geospatial platform. Build scalable data ingestion and processing pipelines, map data models, spatial APIs, map-matching and routing foundations, and reusable platform capabilities. Scale storage, querying, and computation for real-time features, consolidate team-specific solutions, mentor engineers, lead cross-team technical projects, and represent the company in the geospatial community.

Build and ship full-stack web and mobile experiences across Affirm’s consumer products. Break down projects, collaborate with product, design, and analytics teams, develop scalable APIs, write well-tested code, monitor service health, participate in on-call support, review code, and contribute to engineering growth and interviewing.

Lead fraud decisioning engineering initiatives by architecting, building, launching, and maintaining complex backend systems. Drive cross-functional projects from definition through monitoring, write high-quality and resilient code, review technical work, mentor engineers, collaborate with Product, ML, Analytics, and Business teams, and contribute to hiring and interview design.

Develop and integrate software, algorithms, and data-processing pipelines for remote sensing, SAR, RF, radar, and geospatial systems. Responsibilities include architecture, backend and API development, workflow orchestration, sensor-data analysis, system integration, testing, optimization, deployment, and technical documentation. Collaborate across software, systems, data science, and intelligence disciplines while providing technical leadership on complex projects.

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.

Build and operate full-stack features across database, API, and front-end layers using Ruby on Rails. Own complex problems end to end, modernize legacy systems, design durable APIs, improve reliability and developer productivity, and participate in production support. Collaborate with product and engineering teams, document technical decisions, mentor peers, and contribute to architecture, code reviews, and on-call operations. The role also involves using modern developer tooling and working on scalable fleet and service-management software.

Leads architecture and development of scalable, high-availability software systems supporting millions of endpoints. Owns complex multi-team initiatives, makes technical decisions, mentors engineers, establishes engineering standards, and improves software quality. Requires deep Java development, distributed systems, API design, database engineering, system scalability, testing, and AI-assisted development experience.