Top Software Engineer Jobs in St. Louis, MO

Design, build, and maintain secure, performant browser extensions for Chrome, Edge, and other browsers using Manifest V3 and modern APIs. Develop features integrating with web content, backend services, and endpoint agents; optimize reliability; monitor evolving browser standards; and participate in testing, code reviews, and process improvement. The role requires investigating third-party web applications, understanding extension security models, and coordinating effectively with backend and non-browser engineering teams.

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.

Develops, tests, deploys, and maintains software applications, cloud-based solutions, and mobile applications. Responsibilities include application audits, automated testing, quality assurance, documentation, cloud-stack integration, storage services, API integration, troubleshooting, and post-release support. Collaborates with project managers, analysts, and developers to define requirements and deliver optimized solutions for web and mobile platforms.

Define architecture and technical direction for Catalyst’s distributed data platform, including messaging, state management, reconciliation, streaming, storage, CI/CD, and Kubernetes operations. Build Go and Python frameworks, improve reliability and SLOs, lead incident response, maintain secure dependency and artifact delivery, and develop infrastructure automation. Collaborate across teams and with customers, review designs and code, establish engineering standards, and travel internationally up to 25% to support mission-critical deployments.

Owns the architecture and implementation of high-performance real-time streaming systems, including media ingestion, buffering, relay, packetization, telemetry synchronization, and distribution. Designs protocol modules, resolves interoperability challenges, improves latency and throughput, and maintains production reliability through testing, observability, incident response, and automated deployments. Partners with stakeholders, documents architectural trade-offs, mentors engineers, leads technical rituals, and travels internationally up to 25% to support customer and mission requirements.

Design, implement, and support high-performance storage and query infrastructure handling billions of events. Independently scope and deliver complex projects, optimize query performance, improve reliability, participate in on-call rotations, define KPIs and SLOs, reduce operational toil, debug production issues, collaborate cross-functionally, and mentor engineers.

Technical leader designing and implementing backend features for a FHIR-based healthcare data platform. Owns high-level design, microservices, data pipelines, CI/CD, cloud deployments, and clinical reasoning components (dQM/CQL). Guides customer implementations, resolves complex technical challenges, and mentors junior developers to uphold coding and architecture standards.

Design, develop, and maintain scalable web and backend applications, public REST APIs, automated testing frameworks, and cloud-native services. Improve scalability, stability, monitoring, auto-scaling, CI/CD, security, and reliability. Conduct code reviews, troubleshoot production issues, document root causes and operational procedures, and collaborate with distributed engineering teams to deliver fleet-management platforms.

Design, build, and optimize scalable cloud and web software with focus on infrastructure, performance, and hardware integration for IoT devices. Collaborate with hardware teams to ensure connectivity and high availability, implement new features, and improve system efficiency.

Architect, build, and maintain scalable full‑stack applications using React, TypeScript, Node.js, and AWS. Own features end-to-end, optimize performance and usability, collaborate with founders, and use AI tools to accelerate development in a fast-paced startup.

Develop open source SDKs, enterprise APIs, UIs, and backend systems supporting large-scale computer vision datasets. Build scalable, maintainable, performant, and well-tested software for unstructured data and AI workflows. Contribute to enterprise deployments across customer clouds and on-premises environments, while improving tooling, automation, engineering practices, and open source community initiatives in a remote-first team.

Develop custom ServiceNow applications for work order management, scheduling, and dispatch. Collaborate with stakeholders and technical SMEs, enhance event rules and CMDB binding, build REST integrations and user interfaces, and configure Discovery, Service Mapping, MID Servers, Service Graph Connectors, and multisource CMDB. The role also involves creating discovery patterns, preventing duplicate CIs, configuring identification rules, migrating patterns across environments, and supporting multi-tier service discovery.

The Staff SDET will design and implement automated test frameworks using TypeScript, collaborate with developers, and enhance testing processes within CI/CD pipelines.

Provide technical and architectural leadership to the software development team, design software solutions, mentor team members, and drive projects to completion.

The Senior Software Engineer will modernize USPS shipping technology, refactor legacy systems for cloud integration, and develop high-performance services using Go, while collaborating with teams and addressing production challenges.

Design, build, and operate high-performance Places/Search API services; drive architecture and scalability decisions; improve code quality and operational standards; mentor engineers; run experiments and telemetry-driven analysis; participate in feature delivery, on-call rotation, and customer-facing collaboration with automotive and mapping partners.

Design, build, and optimize GraphQL APIs, gRPC services and SQL queries for a promotions engine. Own complex technical problems, improve production scalability and performance, set up DataDog monitoring, participate in on-call rotations, mentor engineers, and deliver end-to-end features in an agile environment.

Build and operate AlphaSense's identity platform across user management, authentication, and authorization. Design scalable RBAC/ABAC/ReBAC systems, integrate authentication patterns (OAuth/OIDC/SAML), implement SCIM provisioning, and expose GraphQL/gRPC/REST APIs. Partner with security on SOC2/GDPR compliance, drive platform roadmap, champion testing, observability, and reliability, and operate autonomously from North America in close collaboration with the Helsinki team.

Own architecture, development, and reliability of ecommerce web applications (Symfony storefront and Laravel back-office). Lead front-end JavaScript/CSS direction, optimize SQL schemas/queries, improve observability and incident response, reduce legacy technical debt, establish AI-assisted development workflows, mentor engineers, and drive end-to-end delivery of scalable customer-facing features.

Build and ship full‑stack product features on a Python/Flask backend and React frontend. Design REST/GraphQL APIs, work with SQLAlchemy and relational data models, integrate LLM/AI features, use async task queues (Celery), and collaborate with product, design, and engineers to deliver reliable, well-tested features end-to-end.

Design, implement, and maintain scalable Java-based software solutions. Collaborate across the SDLC with stakeholders and development teams, integrate DevOps and CI/CD practices, support operational tasks, ensure security and performance, drive feature development, conduct code reviews, and stay current with emerging technologies.

Design, build, and architect stablecoin and crypto infrastructure; integrate DEXs, DeFi protocols, and wallet providers; develop smart contract interactions; expand crypto product functionality and asset selection; collaborate cross-functionally; establish crypto development standards and ensure security and reliability for large-scale user experiences.

Technical leader for Platform & Infrastructure building scalable, resilient cloud-native systems to support large AI workloads. Define architecture, mentor engineers, solve systemic infrastructure bottlenecks, design foundational platform services, and collaborate cross-functionally to ensure secure, high-performance operations.

Lead architecture and scaling of cloud-native infrastructure to support large AI workloads. Mentor engineers, decompose complex systems, design foundational platform services, and collaborate with product, research, and security teams to ensure secure, performant, and highly available GPU/ML infrastructure.

Design, develop, test, and deploy features for the EverHealth platform. Troubleshoot and debug, review PRs, expand unit test coverage, participate in agile ceremonies, and maintain application performance and observability.