Top Senior Software Engineer Jobs in St. Louis, MO

Lead refactoring and optimization of scalable data pipelines, design next-generation distributed storage and processing systems, build clean interfaces for diverse data consumers, mentor engineers, and establish engineering standards and processes.

As a Senior Software Engineer, you will lead the development of scalable backend systems, manage feature development lifecycles, and engage with stakeholders to translate mission needs into technical requirements while ensuring implementation meets criteria.

The Staff Software Engineer will lead implementations, mentor engineers, define technical strategies, and communicate with stakeholders while enhancing federal engineering capabilities.

Design, build, and operate scalable web applications, APIs, services, and AI-enabled workflows. Use AI tools across the development lifecycle, ensure reliability, performance, and observability, contribute to technical decisions, iterate from user feedback, and own production quality and delivery as part of cross-functional squads.

Senior Software Engineer at Twilio will design, build, and maintain scalable communication systems, collaborate with cross-functional teams, mentor engineers, and contribute to architecture and delivery. Responsibilities include writing high-quality code, improving performance and reliability, shipping product features, and participating in technical planning within a remote-first, inclusive environment.

Lead and coach a software engineering team to design and deliver production-grade reference architectures, sample applications, and reusable implementation patterns. Provide hands-on technical leadership across cloud-native, containerized, and distributed systems; drive architecture and adoption of best practices; partner with platform and infrastructure teams; participate in coding, prototyping, and troubleshooting; manage staffing, prioritization, and delivery planning.

Build and maintain the full-stack Raise product: polished donor-facing UIs and backend systems. Own features end-to-end, ensure scalability, reliability, and performance, review AI-generated code, collaborate with Product and Design, write clean testable code, and support observability and incident resolution.

Build and evolve a large-scale search and reporting platform: design and implement streaming data pipelines, improve search relevancy and indexing, scale systems 10x, control costs, ensure production readiness (testing, monitoring, reliability), support escalations, and collaborate on architecture, code reviews, and hiring.

Design, implement, and own production platform subsystems for an enterprise AI control plane. Deliver production-ready Go services on Kubernetes, ensure reliability, observability, and scalability, mentor engineers, drive design docs and code quality, and contribute to the open-source ToolHive/MCP ecosystem.

Lead and mentor a team of engineers while contributing hands-on to complex features. Define architecture, drive development best practices, conduct code reviews, coordinate cross-functional requirements, and ensure timely delivery of high-quality ecommerce marketplace software.

Lead Platform Engineer to design and evolve Subaru.com using Java, AEM, and AWS. Lead architecture and technical delivery, mentor teams, run design and code reviews, enforce quality, and build scalable web applications and services integrating front-end, mobile, and third-party clients.

Owner of end-to-end full-stack features with primary focus on elite Angular/TypeScript frontends. Build real-time UI components (WebSockets/SSE), enforce feature-domain driven Angular architecture, harden API integrations and auth (JWT/OpenID Connect/OAuth2), optimize performance and i18n, and develop high-concurrency backend microservices (Python/FastAPI/Django). Use autonomous coding agents to accelerate and maintain code quality.

Lead company-wide transformation of test automation and quality engineering: define vision and roadmap, architect scalable testing frameworks across server/web/mobile/desktop, integrate AI/LLM for test generation and flakiness management, establish observability and quality gates, mentor engineers, and partner with leadership to embed quality across the SDLC.

Build and ship production frontend features using modern web technologies (Vue.js/TypeScript). Collaborate with product in a cross-functional squad to iterate UX, deliver secure, stable code, and create reusable, testable components. Operate in an AI-first workflow using agentic tools, participate in Git-based development, and apply basic AWS services to solve business problems.

Design and implement backend APIs and performant database schemas (Postgres/SQL); build scalable, testable C# services; work in Agile cross-functional squads; incorporate AI-assisted development tools; and drive engineering maturity and efficiency.

Lead front-end-focused full‑stack development for a multi‑tenant SaaS online banking platform. Build reusable component libraries, migrate legacy UI, optimize UI performance, troubleshoot across front-end and service layers, participate in on‑call rotations, mentor junior engineers, and ensure API‑first integrations and cloud‑native deployments.

Lead full‑stack development of complex research platforms, set technical direction and architecture, integrate data pipelines and evaluation frameworks, mentor engineers, promote AI-assisted engineering practices (e.g., Claude Code), assist hiring/onboarding, and represent technical work across teams to deliver scalable, secure software for digital safety research.

Build polished, maintainable React-based front-end product experiences; evolve front-end architecture and component patterns; translate ambiguous product ideas into executable plans; collaborate with product and design; prioritize UX quality, testing, and pragmatic tradeoffs; mentor and raise team effectiveness at the Staff level.

Develop and maintain embedded firmware and kernel/user-mode device drivers for Ethernet-based networking devices. Design, implement, test, and integrate drivers into a Linux and AUTOSAR communication stack, build SDK components, and create debug/test utilities and automated unit/system tests for safety-critical automotive applications.

Design, build, and support scalable, stable web and mobile digital products. Communicate with stakeholders, estimate scope, lead and mentor engineers, produce extensible technical solutions, and use data-driven iterative development.

Lead platform strategy, architecture, and hands-on development. Design, build, deploy, and operate high-performance, fault-tolerant integrations and platform enhancements. Drive security/compliance, mentor engineers, recruit senior talent, align technology with business goals, and communicate technical vision to stakeholders.

Design, implement, and own complex features and services for a large-scale CPM platform. Lead technical design, build modern UIs, design APIs and JSON/XML contracts, drive performance and reliability improvements, mentor engineers, lead code reviews, contribute to CI/CD and production support, and responsibly employ AI-assisted development tools.

Lead design and implementation of batch and stream loading systems to ingest terabytes daily. Provide technical leadership on the Streamloader team, collaborate with architects, engineers, product, sales, and customers, and develop high-performance distributed software in C++ and/or Java while ensuring system reliability and customer success.

Design, configure, and administer the Splunk observability platform for enterprise-scale log and event ingestion. Optimize pipelines for performance, cost, and retention; integrate Splunk with cloud platforms (AWS, Azure, Kubernetes), CI/CD and deployment tools (Puppet, Ansible), and enterprise systems (ServiceNow, PagerDuty). Implement automation using Python/Bash, manage Splunk apps/roles, and support observability and APM initiatives while collaborating within SAFe using Jira and Confluence.

Lead architecture and evolution of enterprise observability platforms (APM, infrastructure monitoring, session replay, log analytics). Define integration patterns, telemetry standards, and governance. Partner with Engineering, SRE, Product, and Infrastructure to embed observability best practices, evaluate new technologies (OpenTelemetry, distributed tracing, AI-driven observability), drive platform standardization, and manage vendor relationships to improve MTTD/MTTR and system reliability.