Top Senior Software Engineer Jobs in St. Louis, MO

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.

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.

Own quality engineering for high-throughput payment systems by architecting automated regression, performance, stress, and load testing. Build emulators for external payment systems, integrate quality gates into CI/CD pipelines, validate microservices, event-driven architectures, and databases, and use Prometheus and Grafana for observability. Apply AI-assisted testing, synthetic data generation, and edge-case analysis while mentoring engineers and preventing incidents through telemetry-driven testing and post-mortems.

Build and scale ML-optimized HPC infrastructure, manage Kubernetes-based GPU/TPU superclusters, optimize for AI/ML training, and mentor teams while innovating in ML infrastructure.

Build and maintain reliable, secure, scalable backend systems for Lithic’s product platform. Own projects end to end across API key management, reliability, audit logging, search, and API infrastructure. Improve system reliability, reduce technical debt, participate in on-call rotations, and lead team process improvements while collaborating asynchronously across time zones.

Build and operate highly scalable storage infrastructure supporting petabyte-scale imagery data. Responsibilities include developing backend services and APIs, managing object storage and metadata indexing, tuning Elasticsearch, improving disaster recovery, monitoring performance, responding to incidents, contributing to architecture and roadmaps, and advising engineers. The role requires strong production software engineering experience with Go or Python, cloud-native systems, relational and non-relational databases, and highly available services.

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.

Build and maintain Supabase Lite: implement TypeScript-native backend compatible with PostgREST/Auth and @supabase/supabase-js, extend SQLite support, own CLI/tooling and upgrade paths, ensure compatibility with hosted Supabase, engage partners and open-source community.

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

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.

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

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.

The role focuses on optimizing coding practices and collaboration within the engineering team, improving internal tooling, and communicating between teams and leadership.

Design, implement, and ship end-to-end features across backend services and a React web client for a multi-tenant ERP. Own schema design, migrations respecting row-level security, integrations with platform services, and deliver high-quality, performant code with CI/CD, tests, and code review. Leverage AI coding assistants responsibly and collaborate cross-functionally to evolve shared platform libraries and developer tooling.

The Senior Svelte Software Engineer will develop high-quality, scalable Svelte web components, collaborate on design systems, and ensure component reliability.

The Senior Software Engineer will lead teams to build secure, high-scale cloud applications, ensuring system reliability and delivering software solutions.

Build scalable full-stack applications integrating healthcare insights with browser-based and Windows EHR systems. Develop products using FHIR and HL7 interoperability standards, collaborate on technical roadmaps, and implement performant solutions. Mentor junior engineers, conduct code reviews, make technical decisions, and partner with engineering, product, and business stakeholders using Agile processes.

Build and operate reliable backend systems and APIs for high-traffic products. Responsibilities include distributed system design, data modeling, service architecture, performance tuning, automated testing, observability, incident management, and end-to-end feature delivery. The role partners with Product and Design, makes architecture decisions, mentors engineers, and applies AI-assisted development tools responsibly.

Build and ship cross-platform React Native features for iOS and Android consumer applications. Own mobile functionality end to end, including UI, networking, persistence, offline support, testing, performance, observability, and store releases. Collaborate with Product, Design, and QA, maintain native modules when needed, and use AI-assisted tools to improve development speed and quality.

Design, build, test, and deploy production software for an agentic chatbot platform across intake, orchestration, retrieval, answer generation, caching, and integrations. Collaborate with product and technical teams, provide code and merge-request review, mentor junior engineers, and contribute to design, performance, security, and delivery.

As a Senior Backend Software Engineer at Archy, you will lead major product updates, ensuring system stability and scalability, while collaborating with cross-functional teams to enhance dental practice management solutions.