Top Senior Software Engineer Jobs in St. Louis, MO

Lead systems engineering for Hivemind-based autonomy products: define and manage requirements, develop system architectures and trade studies, coordinate hardware/software interfaces, support integration/verification/validation and testing, and identify and mitigate technical risks across the system lifecycle.

Design and implement full‑stack, low‑latency web-based Ground Control Station and C2 systems (map-centric UIs, real-time telemetry, video streaming), lead architecture and APIs, mentor engineers, support field tests and mission deployments, and ensure interoperability with C2 standards.

Join a small AI-native engineering team building and operating Affirm's bank systems. Own end-to-end bank infrastructure, durable workflows, vendor integrations, data platform, CI/CD, monitoring, and examiner-ready documentation. Use AI-assisted tooling to accelerate development, collaborate with Compliance/Risk/Finance, and mentor growing engineering talent.

Design and build end-to-end web and AI-powered dashboard features, scale cross-platform full-stack infrastructure, standardize product patterns, mentor engineers, lead cross-team technical projects, and collaborate with product and design to improve user workflows and AI adoption.

Senior fullstack engineer to build and scale Brigit's consumer finance platform. Own end-to-end features across frontend (React/React Native/TypeScript) and backend (Java/REST/SQL), optimize database and APIs for high scale, integrate 3rd-party services, implement risk and transaction algorithms, improve CI/CD, testing, monitoring, and internal tooling to support millions of users.

Own technically complex, mission-critical areas and define technical strategy for new products. Design and ship full‑stack, AI‑driven features end‑to‑end, build scalable data ingestion and API systems, partner with product/design/customer teams to translate ambiguous problems into measurable outcomes, mentor engineers, and raise engineering quality and standards across the organization.

Serve as the senior software development SME while performing full-stack Java web development and O&M activities. Guide developer teams, prioritize work, coordinate technical meetings, resolve issues, optimize processes, analyze requirements, estimate effort, review code, conduct testing, troubleshoot environments, create technical documentation, and implement software updates. The role requires extensive J2EE experience, SPA development, DevOps and CI/CD expertise, and active Public Trust/MBI clearance supporting an IRS Criminal Investigation system.

Design, build, test, review, and deploy production Java software while making architectural decisions and modernizing a legacy ERP platform. Lead and mentor local and overseas developers, establish distributed-team processes, and collaborate with product, QA, TechOps, and leadership. Own platform components through operational health, use AI coding assistants and agentic tools, improve integrations and workflows, and contribute to API, database, and modernization initiatives.

Senior full-stack engineer responsible for architecting, developing, deploying, monitoring, and supporting production capabilities across a React, Node.js, PostgreSQL, Rust, and Azure Kubernetes platform. The role includes delivering AI and LLM features, owning complex technical initiatives, improving reliability and security, contributing to architecture and engineering standards, partnering with stakeholders, and mentoring engineers.

Build and operate full-stack, cloud-native applications for network automation and mission platforms using Python, Go, JavaScript, and TypeScript. Develop APIs, AI agents, generative user interfaces, integrations, and telemetry workflows. Contribute to CI/CD, Infrastructure as Code, containerized deployments, production troubleshooting, security, observability, and architecture. Collaborate across software, cloud, platform, product, and security teams in an ambiguous, mission-focused environment.

Build and ship robust Android features for ClassPass in a large modular codebase. Collaborate with product and design, mentor junior engineers, conduct code reviews, write technical documentation, solve complex problems, improve systems, and contribute to architectural decisions using Kotlin and Jetpack Compose.

Design, deploy, enhance, and support secure custom government network platforms and cloud services. Manage CI/CD pipelines, build systems, testing frameworks, distributed databases, and storage ecosystems. Lead technical initiatives, code reviews, security patching, Agile SDLC releases, and system performance improvements. Collaborate with Operations, Engineering, and SRE teams to troubleshoot complex issues and deliver resilient application delivery networks.

Designs and delivers complex cross-system integrations, APIs, automation workflows, and reusable engineering solutions. Diagnoses root causes, improves reliability, documents risks and runbooks, participates in on-call support, and partners with commercial, product, and engineering stakeholders. The role also mentors engineers and non-engineers, guides technical trade-offs, scopes ambiguous problems, and delivers measurable operational improvements.

Owns Shopify checkout and post-purchase extensions, experimentation reporting, and revenue-critical APIs across PHP, TypeScript, MySQL, BigQuery, and Google Cloud. Designs secure REST services, investigates production issues, participates in on-call, and maintains unit and end-to-end testing without a separate QA handoff. The role requires Staff-level technical ownership, system-wide architectural judgment, AI-assisted development, mentoring, and collaboration in a remote, high-autonomy environment.

Join Archy as a Senior Platform Software Engineer to enhance dental practice management through a scalable SaaS solution, focusing on cloud infrastructure, CI/CD pipelines, and AI integration.

The Staff Software Engineer will shape technical direction, build developer platforms, and design AI agents, enhancing developer productivity and collaboration across teams.

The Staff Software Engineer will lead technical strategy, ensure system availability, and develop backend systems at scale, collaborating across teams to drive capacity modeling and operational quality.

As a Senior Software Engineer, you will design and maintain systems, mentor team members, and improve both code quality and team practices.

Lead development and reliability of real-time and batch payment-processing systems across authorization, clearing, settlement, disputes, and card-network integrations. Build scalable, secure, low-latency services using Java, Python, Kotlin, and AWS; improve network peering infrastructure, failover, and capacity. Own initiatives from planning through launch, participate in on-call rotations, reduce technical debt, and drive cross-functional engineering improvements and strategic planning.

Own and develop Curri’s React Native driver applications across iOS and Android. Lead mobile features from problem definition through deployment and measurement, build offline-first capabilities, background geolocation, and push notifications, and debug native modules and production issues. Collaborate directly with drivers, operations, Product, and Design while contributing to full-stack work and AI-assisted development.

Build and maintain backend computation engines for solar and electrical design. Develop simulation and optimization systems for PV and battery storage layouts, component selection, and electrical configuration. Translate physical models into reliable, scalable software, shape computation infrastructure, write tested code, mentor teammates, collaborate cross-functionally, and own services through production and on-call support.

Modernize and maintain a large-scale React Native mobile app with offline-first architecture, BLE device integrations, data synchronization, and performance improvements. Influence architecture, mentor developers, collaborate across teams, and occasionally visit customer farms to understand workflows.

Modernize and evolve a large-scale React Native mobile app with offline-first architecture, BLE device integrations, local data storage and sync. Improve performance, reliability, and scalability, influence architecture, mentor developers, collaborate cross-functionally, and occasionally visit farms to understand user workflows.

Own HUD’s production infrastructure and backend platform systems, focusing on reliability, scalability, performance, cost, deployment safety, and developer experience. Build AWS infrastructure with Terraform and Kubernetes, improve CI/CD and observability, design resilient services and asynchronous systems, manage incidents, and develop internal automation and tooling. The role supports high-availability AI, marketplace, and data-heavy workloads.

Develop and launch scalable web and mobile healthcare applications, APIs, integrations, and cloud infrastructure. Contribute to the technical roadmap, observability, security, compliance, and AI/ML infrastructure. Partner with the founding team and data science leadership to incorporate LLMs, support HIPAA and SOC 2 requirements, and build reliable products for patients and enterprise healthcare customers.