Top Senior Software Engineer Jobs in St. Louis, MO

Design, build, and operate low-latency authentication and authorization services (OAuth, sessions, tokens, 2FA, account recovery). Lead technical designs, ensure strong security and observability, collaborate cross-functionally, simplify integrations, and mentor engineers while running production services with measurable SLOs.

Lead design and delivery of large-scale distributed systems for Catering & Events. Own architecture, drive technical strategy, mentor engineers, collaborate with Product and Design, ensure scalability, reliability, observability, and champion AI adoption to improve developer productivity and product capabilities.

Lead design and implementation of Headway's insurance systems (eligibility, pricing, matching, claims). Build data-intensive, ML-powered platforms and automation, mentor engineers, write high-impact code, and improve accuracy and reliability across state and payer complexity to scale insurance-covered therapy.

Design, develop, modernize, test, and maintain data-driven software and relational databases for FAA aeronautical information distribution. Gather requirements, implement COTS integrations, troubleshoot production issues, produce technical documentation, participate in reviews, and provide technical leadership and mentoring across the software development lifecycle.

Lead end-to-end feature development across frontend and backend for an enterprise data analytics platform. Design, implement, and maintain React UIs, backend services, APIs, databases, and distributed systems. Collaborate with Product, UX, and Engineering, mentor engineers, improve quality through testing/CI, and introduce new technologies including AI-assisted development.

Senior backend engineer on an education-focused technology consulting team. Own complex backend systems end-to-end: estimate scope, build and support production Python services, design REST/GraphQL APIs, work with cloud and Docker, use relational databases, maintain strong automated tests and Git workflows, and represent technical work to clients. Role values mentorship, ownership, and mission-driven work.

As a Senior Principal Engineer, you'll define and drive the technical strategy for customer experience platforms, lead architectural decisions, and mentor engineering teams to enhance customer and agent experiences.

Build and maintain on-chain smart contracts and backend services for branded USDC-backed stablecoins. Own issuance, reserves, mint/burn, and rewards systems; drive architecture, security, and operational excellence; ship features with product and design partners and ensure well-tested, auditable production deployments.

Lead technical strategy and architecture for Affirm Bank's cloud, data, vendor integrations, and operational tooling. Design, build, and operate high-stakes systems end-to-end, own incident response, vendor selection, and the Bank↔Affirm Inc integration boundary. Ensure examiner-ready documentation, compliance, reliability, and observability while mentoring engineers and pushing AI-assisted engineering practices to increase velocity and product safety.

As a Senior Frontend Software Engineer, you'll lead the development of major features using React and TypeScript, ensuring performance and integration with backend systems. You'll also manage releases, improve team efficiency, and contribute to a customer-centric product experience.

Lead architecture and implementation of software for autonomous UAS systems; mentor engineers; ensure compliance with aerospace standards; optimize CI/CD pipelines.

Design and implement the core components of the Agents Python framework, focusing on API and abstraction development for AI-driven applications.

Develop and enhance the new Stores platform while supporting various e-commerce tools to improve seller success online.

As a Senior Fullstack Software Engineer at Vanta, you will lead complex projects, set technical direction, design and develop new functionalities, and contribute to the engineering culture while mentoring other engineers.

The Software Engineer will develop and support the MEMX Trading system, focusing on high throughput event-sourcing applications and resolving production issues.

Design, build, and maintain secure, scalable cloud automation and tooling for Azure Government. Operate mission-critical production systems (24x7 on-call), implement IaC and DevOps pipelines, resolve Azure PaaS and app issues, enforce federal security/compliance, manage IAM and deployments, support audits, and maintain technical documentation.

Seeking experienced Senior Backend Engineers to join a collaborative team, focusing on backend systems, shared services, and product features aimed at improving user experiences and monetization.

Design and implement DataPath on silicon. Write efficient, modular code with thorough testing. Requires experience in packet forwarding and virtualized Linux environments.

Develop automated solutions for material handling, including software design, integration, testing, support, and project management, primarily in back-end development.

The Senior Full Stack Software Engineer will oversee technical development in a B2B SaaS healthcare environment, mentor junior engineers, and lead product features.

As a Senior Software Engineer, you'll build AI-powered features, integrate LLMs, design scalable systems, mentor teammates, and collaborate to enhance user experiences.

The Software Engineer will develop customer-facing integrations, build APIs, enhance security, and improve system reliability while collaborating with multiple teams.

The Senior Web Software Engineer will build and maintain web components, own features from inception to production, implement designs, partner with teams, and impact product evolution.

The Senior Mobile Software Engineer will develop user-facing features for a cross-platform app, ensuring code quality and functionality throughout the entire lifecycle of features.

As a Senior Backend Software Engineer at Step, you'll own features from inception to production, improve Kotlin services, ensure code quality, and work collaboratively in a small team.