Top Software Engineer Jobs in St. Louis, MO

Improve performance and scalability of web applications by identifying and resolving front-end and back-end bottlenecks. Optimize load times, API responses, and database queries; develop scalable features across the stack, monitor performance, conduct code reviews, troubleshoot production issues, and collaborate with product, design, and engineering teams.

Lead design and delivery of platform capabilities that power a Federated GraphQL API and event-driven systems. Build and optimize gRPC endpoints, GraphQL APIs, and SQL for scale; own observability (DataDog, Bugsnag), mentor engineers, drive integrations, improve performance and reliability, and support customer-facing product teams across the organization.

Own the technical direction of a core Helius backend system, including architecture, reliability, performance, roadmap, and production operations. Design scalable distributed systems, storage, streaming, or edge infrastructure; drive profiling and performance improvements; establish operational excellence; partner with founders on strategy; mentor engineers; and lead ambiguous cross-team initiatives.

Own and advance a core Helius backend system supporting Solana infrastructure. Design and release high-performance products, optimize latency and throughput, make architectural decisions, improve observability and incident response, and mentor engineers. The role requires end-to-end ownership of production systems at scale, with close collaboration with founders and engineering leadership. Relevant systems include data streaming, historical APIs, account indexing, and access control infrastructure.

Develop full-stack solutions using TypeScript and AWS cloud technologies. Responsibilities include building GraphQL APIs, business logic libraries, AWS Lambda functions with CDK, AWS Glue automation, and Angular/Ionic user interfaces. The engineer will also support CI/CD, Git repositories, linting, developer workflows, requirements management, and HIPAA-compliant software development. Collaboration with engineers, management, and business analysts is required.

Execute scheduled, ad hoc, and release-milestone software tests; review test cases; report defects in issue-tracking systems; communicate status in standups; and collaborate with software test managers and development teams. The role requires knowledge of QA methodologies, black-box, grey-box, and white-box testing, strong communication and organization, independent and team-based work, and participation in planning and professional meetings.

Seeking a Senior Software Engineer with 5+ years of experience to design and develop large-scale distributed systems, mentor junior engineers, and manage complex projects in a dynamic setting.

Lead Elasticsearch performance engineering from architecture through production. Develop performance models, optimize distributed systems, profile bottlenecks, build benchmarks, detect regressions, and improve scalability across stateful and serverless architectures. Design AI-assisted optimization and benchmarking tools, collaborate across teams, define performance strategies, and mentor engineers. The role requires deep Java, JVM, concurrency, distributed systems, and search or data-store performance expertise.

Develop and optimize Elasticsearch performance across distributed and serverless architectures. Responsibilities include implementing performance models, profiling systems, identifying bottlenecks, building benchmarks and regression detection, improving logging, metrics, vector search, and ES|QL performance, and creating AI-assisted optimization tools. The role also involves architectural and code-level optimization, technical analysis, peer reviews, and guidance for fellow engineers.

Leads the technical strategy, architecture, implementation, and delivery of a scalable ecommerce platform for vehicle discovery, configuration, checkout, payments, order management, fulfillment, and ownership experiences. Builds and tests distributed systems, drives code quality and technical decisions, partners with product and UX teams, simplifies complex problems, and mentors engineers while balancing customer impact, business needs, and long-term technology excellence.

Lead design, implementation, and operation of Signifyd's GCP/Kubernetes cloud platform. Architect scalable, secure infrastructure, embed AI-driven automation, own SLOs and incident response, improve developer experience via CI/CD/GitOps tooling, mentor engineers, manage cloud capacity/FinOps, and build observability and security into the platform.

Design, develop, and maintain Java-based backend services and APIs for KeeperApp. Own backend components, optimize MySQL schemas/queries, ensure performance and reliability, apply secure coding practices, participate in code reviews, and collaborate with product and engineering teams to deliver features iteratively.

Remote Senior Software Engineer who evaluates Microsoft and complementary technologies, designs and implements custom software (C#, JavaScript, SQL), applies cloud and DevOps practices (Azure/AWS, CI/CD, containers), mentors and networks professionally, and continuously learns and advises clients.

Lead development of the production toolchain that compiles complex Python packages (e.g., NumPy, SciPy, PyTorch). Build and maintain build/release pipelines, create and review conda recipes, automate processes, mentor engineers, run incident response and postmortems, and advise leadership on technical tradeoffs. Partner with distribution and wheels teams and validate AI-assisted code where used.

Design, build, and scale embedded connectivity and security for distributed energy devices. Implement networking (Ethernet/Wi‑Fi/Thread/Zigbee/BLE), secure provisioning, OTA firmware pipelines, telemetry, and diagnostics. Support testing, certification, manufacturing validation, and cross-functional collaboration from prototype to deployment.

Lead design and implementation of gameplay and engine systems on Linux platforms. Mentor engineers, define technical specs, manage Linux infrastructure, optimize performance and security, integrate art, maintain documentation, support live services and mobile (iOS/Android) ports, and coordinate cross-team standards and tooling.

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

Seeking a Staff Software Engineer to design and build cloud-deployed systems. Must have extensive programming and leadership experience in software engineering.

The Senior Software Engineer, Protocol will architect and develop core protocol components for a blockchain while optimizing distributed systems. Responsibilities include enhancing performance, solving distributed systems problems, and contributing to engineering standards in collaboration with research and product teams.

Lead development of automated API, UI, and end-to-end tests for a real-time trading platform. Extend AI-assisted test generation, build scalable CI/CD test frameworks for order lifecycles and market-data streams, reduce flakiness, triage failures, mentor engineers, and drive quality and testability across the product.

As a Senior Software Engineer, you will develop key product features for millions of users, collaborate with teams, and mentor others.

Lead development of AI-powered full-stack applications, mentor engineers, define technical direction, build performant front-end and scalable backend services, integrate LLMs/RAG, and establish engineering best practices for production AI workflows.

Design, build, test, and deploy secure mission-planning software. Maintain secure CI/CD, containerized deployments, automated testing, and security-scanning workflows. Integrate AI capabilities, investigate vulnerabilities, support remediation, produce technical design documentation, and collaborate with stakeholders and customer leads.

Build and optimize high-volume web applications using .NET, Node, React and AWS; maintain and improve existing systems; troubleshoot bugs; perform code reviews; mentor junior engineers; participate in on-call rotation; and improve scalability and performance.

The Principal Software Engineer will lead the design and build-out of an AI Context Layer, ensuring high-quality data for AI systems, while managing access control and developer interfaces, and leading cross-team projects.