Top Senior Software Engineer Jobs in St. Louis, MO

Lead quality assurance and test strategy across Agile teams, drive automation for testing, mentor QA teams, and ensure high-quality software delivery.

Designs, develops, and deploys AI-driven, cloud-native applications on Azure. Builds RAG knowledge systems, AI agents, secure APIs, and orchestrated workflows using C#, .NET, Azure services, Docker, and CI/CD. Collaborates with stakeholders, ensures observability and security, supports production incidents, and provides documentation and knowledge transfer.

The Senior Software Engineer will lead the development of payment systems, oversee key subsystems, mentor engineers, and ensure high-quality code and architectural standards while collaborating with cross-functional teams.

This role involves leading web platform initiatives, mentoring senior engineers, architecting web applications, and implementing technical strategies for improved performance.

The Senior Software Engineer will design and develop scalable applications, enhance DevOps practices, and drive continuous improvement within infrastructure and systems.

The Senior Software Engineer will lead and support a team in developing reliable and scalable backend systems, collaborating on product development, and improving infrastructure for secure communication between services.

Lead and build a new Trust & Safety engineering domain: design and implement systems to detect and mitigate fraud, billing anomalies, and credential abuse. Architect product and operational solutions, mentor engineers, define processes, and deliver scalable, auditable safety tooling across internal and external workflows.

The Senior Software Engineer will design and implement solutions for a restaurant platform, enhance performance and collaborate with teams to solve challenges.

As a Staff Software Engineer, you'll develop full-stack software applications, mentor team members, and participate in design discussions while advocating for best coding practices.

Lead the design and delivery of scalable data platform services, guide engineers, and improve engineering practices while collaborating with cross-functional teams.

As a Staff Software Engineer, you'll develop an AI-first platform, design cloud-native APIs, and collaborate on Site Builder experiences with a focus on scalability and quality code.

The role involves providing technical leadership, hands-on execution, and cross-team influence in software engineering, focusing on solutions for scaling and performance challenges while using AI tools.

Join the Query Integration team to enhance MongoDB's query engine, integrating features, improving performance, and contributing C++ code with a focus on database systems.

Design and build secure, scalable systems as a Full-Stack Software Engineer, leveraging expertise in Next.js, TypeScript, PostgreSQL, and AI tools to enhance cybersecurity within global infrastructure.

The Senior Full-Stack Software Engineer will design, build, and maintain secure, scalable web applications using modern technologies, with a focus on AI-assisted development and application security.

As a Systems Engineer, you will enhance Windows support for Swift and develop features for internal projects and the Swift community, focusing on system architecture and tooling improvements.

As a Backend Software Engineer, you will design and implement backend systems for mobile and web experiences, lead technical decisions, and optimize performance.

Develop and maintain ClickHouse's billing platform, integrate with external systems, design secure frameworks, and collaborate with cross-functional teams to enhance business processes.

As a Software Engineer, you will design, develop, and integrate capabilities in a complex system while collaborating with team members to deliver impactful solutions.

Build and deliver end-to-end product capabilities using Python and Next.js/TypeScript. Lead design, implementation, reliability, observability, CI/CD, and integrations. Champion AI-assisted development practices and agentic coding workflows, collaborate cross-functionally, and ensure production readiness and operational excellence.

Senior technical leader responsible for architecting and delivering complex, distributed, cloud-native systems on Microsoft Azure; driving adoption of AI-assisted development tools; implementing observability, monitoring, and reliability practices; leading cross-team delivery, performance optimization, and incident response; and mentoring engineers in design and best practices.

Lead a hands-on engineering team to improve reliability, reduce technical debt, and maintain Greenshades' payroll/HR/tax products. Drive AI-first workflows, own reliability backlog and incident root-cause analysis, set engineering standards, partner with product/QA, report to the CTO, and recruit and develop engineers.

Establish and scale software quality practices for AI-driven cybersecurity products. Design tests for deterministic and probabilistic behavior, integrate validations into CI/release pipelines, expand test methodologies (integration, system, stress, workflow), maintain test environments and observability, and build tooling and fixtures for repeatable test conditions while collaborating with engineering to shift quality-left.

The Senior Software Engineer will design backend services, improve data pipelines, and enhance reporting infrastructure while mentoring other engineers. This role supports capital partners by ensuring accurate data flow through Upstart's platform.

Lead the technical direction of Care & Onboarding platforms by driving architectural decisions, overseeing large initiatives, and enhancing engineering quality.