Top Senior Software Engineer Jobs in St. Louis, MO

Designs, develops, tests, integrates, debugs, and sustains non-embedded software for military platform health management systems. Translates customer requirements into software architectures and implementations, supports CI/CD and Agile development, manages interfaces and documentation, troubleshoots user issues, improves software processes, and contributes to research, project management, supplier oversight, compliance, and certification activities.

Designs, develops, tests, maintains, and integrates non-embedded software for the Tomahawk missile program. Translates customer requirements into software designs, resolves technical issues, supports users, implements modern development technologies, and documents software research and development while meeting safety, industry, and government standards.

Leads the development and deployment of data solutions using Palantir Foundry and AIP. Manages engineering teams, coaches team members, oversees project planning and execution, analyzes system interactions, manages client relationships, and drives innovation. The role applies software engineering, data engineering, analytics, and AI/ML techniques to deliver scalable client solutions while maintaining technical and professional standards.

Leads the development and deployment of software and data solutions using Palantir Foundry and AI/ML technologies. Responsibilities include data engineering, analytics, system improvement, client account management, project ownership, team leadership, coaching, stakeholder engagement, and continuous improvement. The role requires building scalable applications with large datasets and delivering customer-focused solutions.

Develops and maintains simulation models, visualizations, virtual environments, and infrastructure supporting F-22 software and hardware development and testing. Responsibilities include requirements analysis, simulation design, coding, data processing, verification and validation, test execution, documentation, hardware integration, and modernization of legacy systems. The role collaborates with cross-functional engineering teams in an agile environment and supports real-time simulation frameworks, operating systems, networks, and emerging technologies.

Develop and prototype sensor-fusion algorithms for tactical aircraft network operations using mathematical and statistical techniques. Analyze multimodal sensor data, apply Kalman filtering and probabilistic models, evaluate algorithm performance, document requirements and analyses, and transition successful prototypes into production software. Collaborate with software architects and customers on algorithm design and requirements. The role requires a bachelor’s degree, relevant sensor-fusion experience, U.S. citizenship, and ability to obtain a Secret clearance.

Design, develop, test, and maintain embedded application software for air-domain missions. Translate customer requirements into software architecture, perform unit/integration testing, support system integration and verification, participate in peer reviews, and produce software documentation while meeting safety, regulatory, and customer standards.

Develops and maintains simulation software, models, visualizations, virtual environments, and frameworks for software and hardware verification. Responsibilities include requirements analysis, simulation design, testing, data processing, validation, documentation, system integration, modernization, and project support. The role collaborates with engineering teams using Agile methodologies and supports multiple Boeing programs across commercial and defense applications.

The Founding Engineer will lead the development of Sailor Health's AI-powered platform, building systems for patient care and mentor the engineering team.

Build the core AI platform for an AI-native trading experience. Develop a high-performance Rust backend supporting streaming responses, low-latency tool execution, caching, and model orchestration. Design secure, observable APIs and runtime components with authentication, authorization, rate limiting, auditing, tracing, retries, and fallbacks. Build safe trading action infrastructure with deterministic previews, confirmations, idempotency, and audit logs while partnering with product and frontend teams.

Own and improve Hex’s cloud infrastructure, CI/CD, observability, databases, security, cost management, and single-tenant deployment systems. The role involves selecting and delivering infrastructure projects, operating Kubernetes and AWS environments, scaling PostgreSQL, implementing infrastructure as code, and building customer-facing platform capabilities. Engineers are expected to handle on-call responsibilities, write application code when needed, and independently turn ambiguous infrastructure problems into shippable solutions.

Build and ship backend features end-to-end using Ruby on Rails and SQL. Lead complex technical projects, solve architecture challenges, establish standards, conduct meaningful code reviews, resolve high-risk bugs, document systems, collaborate across engineering teams, and mentor junior engineers.

Own QA strategy and release quality for POS, back-office, and payments products. Build automated unit, integration, API, contract, and end-to-end tests; integrate testing into GitHub Actions; validate hardware, offline modes, payment flows, and upgrades; establish release gates and test environments; monitor quality metrics; reproduce merchant issues; and coach engineers on testable design and quality practices.

Leads software testing for Boeing mission systems, developing test plans, verification procedures, test environments, and testing strategies across emulation, simulation, development kits, and hardware. Ensures requirements compliance, safety- and mission-critical testing, software process adherence, and coordination across technical and systems teams. Executes and documents testing, supports research and development projects, and mentors other engineers. The role is fully onsite in Berkeley, Missouri, and requires an active Secret clearance and U.S. citizenship.

Leads mission-critical software architecture, design, implementation, integration, verification, and lifecycle maintenance. Ensures compliance with software processes, policies, reference architectures, and industry standards. Coordinates across Mission Systems teams, supports containerized architecture, executes research and development projects, collaborates on testing, and mentors engineers. The role is fully onsite in Berkeley, Missouri and requires an active Secret clearance, SAP access eligibility, U.S. Person status, and successful completion of a technical assessment.

Designs, develops, tests, integrates, and maintains non-embedded software for the Navy Tomahawk missile program. Responsibilities include MBSE, requirements management and verification, system architecture, software development, testing, interface coordination, debugging, documentation, and software process improvement. The role collaborates across disciplines, supports systems integration, ensures compliance with customer and government standards, and provides technical guidance to less experienced engineers.

Lead design, development, testing, debugging, and maintenance of embedded software for vehicle health management on air vehicle/avionics systems. Translate customer requirements into software designs, integrate software with specialized hardware, improve system efficiency and stability, guide testing and adoption of emerging tools, and oversee supplier and internal team performance and embedded software project management.

Develop and maintain cloud-native, non-embedded software and microservices for aircraft and vehicle health management platforms. Responsibilities include software architecture, design, coding, testing, integration, debugging, root-cause analysis, customer support, technology evaluation, process improvement, and participation across the Agile software development lifecycle within a CI/CD environment.

Design and maintain automated testing frameworks for cloud-scale distributed systems. Build performance, load, stress, integration, API, end-to-end, chaos, security, and infrastructure tests. Integrate continuous testing into CI/CD pipelines, analyze observability data, validate Kubernetes and microservices environments, and collaborate with Engineering and SRE teams to improve reliability. The role also participates in on-call rotations and helps establish QA strategy and standards across GPU infrastructure, serverless endpoints, storage, billing, and event-driven systems.

Build and operate Dragos’s web application, GraphQL and gRPC APIs, and client SDKs. Develop React and TypeScript features, design versioned API contracts, maintain Python, TypeScript, and Go SDKs, and collaborate with Product, Design, and backend engineering. Improve performance, accessibility, observability, security, testing, and code quality while supporting security data at scale.

Lead development of Toast’s consumer-facing web experiences, building scalable guest and restaurant features across the stack. Collaborate with frontend, backend, iOS, and Android engineers using React, TypeScript, Next.js, APIs, and backend services. Own projects from development through launch, monitoring, and analysis while experimenting with users and influencing consumer product strategy.

Design and implement C++ features for MongoDB’s replication infrastructure, improving availability, recovery, consistency, performance, and fault tolerance. Diagnose distributed-systems issues, develop comprehensive tests, collaborate across engineering teams, participate in design and code reviews, and mentor junior engineers. The role involves owning technical work from investigation through delivery and contributing to major MongoDB releases.

Develop and maintain MongoDB server workload resilience infrastructure in C++ or Rust. Design workload policies for rate limiting, prioritization, overload mitigation, availability, and performance. Write unit and integration tests, investigate failures, improve observability, diagnose and fix complex distributed-system issues, and lead technical projects. Collaborate across engineering teams, mentor junior engineers, participate in hiring, and improve operational readiness, monitoring, incident management, and rollout processes.

Lead the design, development, and operation of integrations and API products. Establish standards for API contracts, authentication, authorization, versioning, reliability, observability, documentation, and developer experience. Drive cross-team system architecture, production readiness, scalability, security, and resilience while mentoring engineers and aligning technical decisions with product and business goals.

Lead development of scalable Java software applications and high-availability services. Design architectures, solve complex system challenges, improve performance and scalability, and maintain quality standards. Collaborate cross-functionally, mentor junior engineers, own technical initiatives, address support-driven issues, and implement robust testing practices for mission-critical IT operations products.