Top Senior Software Engineer Jobs in St. Louis, MO

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.

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 engineering and develop API-focused full‑stack solutions for brokerage products. Design scalable architectures, build secure cloud-native applications (AWS), drive API strategy, implement CI/CD and DevOps practices, mentor team members, and ensure code quality via TDD/BDD and security/static analysis tools.

Design and build Java/J2EE Spring-based APIs and multi-layer applications; develop web services and database schemas (DB2/Oracle) with PL/SQL; participate in code reviews, unit/integration testing; coordinate technical deliveries across teams and support CI/CD and DevOps collaboration.

Design, develop, and maintain scalable full-stack applications for intermediary clearing and custody platforms. Collaborate with product, architecture, and engineering teams to modernize applications, implement cloud migrations, build APIs, automate workflows, and improve CI/CD, observability, security, and deployment practices in an Agile environment.

Design and build Java-based, messaging and microservice applications. Lead API design, cloud/container solutions (Docker, Kubernetes, AWS/Azure), CI/CD, and relational database development (DB2/Oracle). Provide technical leadership, mentoring, code reviews, and resolve cross-technology roadblocks. Work on blockchain and digital asset solutions (Ethereum, Solana) and smart contracts (Solidity, Rust, Move) within financial services.

Build and scale the internal developer platform: create tools, services and automation (CI/CD, canaries, feature flags, access workflows) using IaC (Pulumi/Python) and Kubernetes to enable safe, fast shipping. Drive platform initiatives, mentor teams, lead AI tool adoption for engineering, participate in on-call and design/code reviews, and ship major improvements across the organization.

Design, develop, and maintain scalable, secure backend services and APIs for a healthcare caregiver platform. Drive cloud-native modernization (microservices, serverless), ensure compliance (HIPAA, OWASP), troubleshoot production issues, optimize performance, mentor junior engineers, and collaborate with product and architecture teams to deliver reliable, high-performing solutions.

Design, develop, and deliver scalable backend systems and components using .NET 10 and C#. Build and maintain databases and messaging infrastructure (PostgreSQL/SQL Server, RabbitMQ), deploy with Docker and AWS, apply DDD and ORMs, triage/prioritize work, and contribute to distributed, event-driven architecture with emphasis on reliability and idempotency.

Own design, implementation, and production support of Windows kernel-mode enforcement drivers (filesystem, process/thread, handles, registry) and the kernel/user-mode enforcement boundary. Reduce enforcement latency at scale, extend enforcement to containers and isolation, ensure compatibility across Windows builds, handle driver signing and deployment, collaborate cross-platform on policy and the Rust userspace agent, and mentor engineers while driving technical direction and operational stability.

The Senior Software Engineer II at Freenome will design and develop reliable backend services, mentor junior engineers, and collaborate with cross-disciplinary teams in a remote setting.

Lead the long-term technical vision and architecture for ServiceTitan's iOS platform. Design scalable mobile frameworks, define data access patterns via GraphQL, champion TCA, adopt Apple platform capabilities, integrate AI-assisted developer tools, drive cross-org alignment, mentor senior engineers, and set engineering standards for code quality, performance, testing, and extensibility.

Design and implement automated test frameworks and data validation utilities for enterprise data platforms. Validate data transformations, pipelines, lineage, and performance across Databricks, Snowflake, Spark, Hadoop and cloud environments. Integrate tests into CI/CD, perform white-box and performance testing, investigate production defects, and collaborate with Data Engineering, Analytics, and business stakeholders to ensure P&C insurance data quality and regulatory readiness.

Design, build, and maintain scalable data pipelines and ingestion agents for fleet robotics. Define efficient data formats/protocols, implement observability and big-data processing (Spark/Kafka), and build cloud tools (S3, Athena, SageMaker) for analytics, IoT integration, and long-horizon forecasting to improve robot performance and operational insights.

Design, build, and scale GraphQL APIs, low-latency gRPC services, and SQL-backed wagering flows for online casino products. Own complex technical problems end-to-end, improve production performance and observability (DataDog), mentor engineers, and deliver integrations with game providers while operating services on Kubernetes and participating in on-call rotations.

Lead design and implementation of scalable APIs and agent communication layers for an AI-agent driven advertising marketplace. Build high-throughput backend systems, integrate agent frameworks and adtech partners, drive architecture for authentication and protocols, mentor engineers, and prototype agent communication patterns while collaborating with product and design.

Build and own end-to-end, production-grade full‑stack features across backend, frontend, data pipelines, and infrastructure. Collaborate with stakeholders to translate business problems into shipped software, drive cross-team initiatives, and improve tooling and code quality. Use AI coding tools daily to accelerate development and maintain reliability for customer-facing products.

As a Software Engineer, you'll design and develop microservices using a cloud-native tech stack, with a focus on financial services and secure systems.

Design, implement, and optimize Elasticsearch core storage and query engine components for observability workloads. Drive architectural improvements, resolve performance bottlenecks in indexing and serialization, optimize data layouts for object storage, lead cross-organizational initiatives, mentor engineers, triage community issues, and write idiomatic modern Java in a distributed team.

Drive architecture and technical vision for Elasticsearch core storage and query engine. Lead performance and storage-efficiency improvements, design indexing/serialization/data layouts, mentor engineers, coordinate cross-organizational initiatives, triage community issues, and write idiomatic modern Java for logs and metrics workloads.

Build and maintain the GG App across Windows, macOS, and iOS including installers, background services, auto-update systems, enterprise deployment paths, health reporting, AWS backend, and documentation. Lead architecture decisions, mentor engineers, participate in on-call support, and champion AI adoption and automation across engineering.

Lead and manage an API engineering team owning core services for Fundrise investor applications. Set technical direction, coach engineers, drive architecture, ensure production quality, security, monitoring, and coordinate cross-team delivery.

Lead and implement backend and developer-experience initiatives across Clojure and Go systems. Define architecture, build and operate distributed services, event pipelines, databases and APIs, improve observability and reliability, mentor senior engineers, and drive cross-team delivery from ambiguity to measurable outcomes while participating in on-call rotation.

Own and improve Plane's automated test suite for web and desktop clients: design frameworks, cover hard-to-test scenarios (concurrency, offline/recovery, agent-driven nondeterminism), keep tests fast and reliable, run suites in CI, test cloud and self-hosted environments, and triage failures across teams and community PRs.