Top Software Engineer Jobs in St. Louis, MO

Build and scale a telemedicine platform using React, TypeScript, Python, Flask, and PostgreSQL. Own features through development, deployment, and launch; develop integrations; write tests; conduct design and code reviews; resolve production issues; and collaborate with Product, Design, and Quality teams in a Scrum environment. The role also involves mentoring engineers, improving development processes, and communicating technical decisions to nontechnical stakeholders.

Build and ship production software across the frontend and backend, working closely with founders, customers, and product teams. Develop AI-powered features and systems involving web scraping, unstructured data, PDF parsing, and cloud infrastructure. Translate real-world real estate and financing problems into technical solutions, make high-impact decisions, and own shipped code. The internship may convert to a full-time role.

Own and expand a Three.js-based in-browser solar configurator: implement and optimize 3D geometry tools and workflows, build product-facing frontend features, collaborate with backend and computational teams, translate solar physics into usable design tools, define frontend/3D architecture, and ensure performant, stable UX across edge cases.

Own and expand a Three.js/R3F in-browser solar configurator: build and optimize 3D geometry tools and UX, collaborate with backend and simulation teams, ensure performant real-time rendering, and deliver frontend product features across the Aether platform.

Senior backend engineer responsible for designing and implementing new features, scaling and optimizing the platform, improving Postgres and Elasticsearch performance, fine-tuning LLMs, and making architectural decisions. Collaborate with engineering team, take ownership of features, write performant, maintainable code, and help shape product and infrastructure for data-intensive applications (NLP, search, indexing).

Senior backend engineer responsible for designing, building, testing, and documenting scalable Node.js/TypeScript services and APIs. Lead projects end-to-end, enforce coding standards, write technical specifications, optimize performance, and mentor junior engineers. Champion Agile and CI/CD practices while providing technical thought leadership on backend architecture and data modeling.

Build and scale mission-critical tips, earnings, and payroll platforms for restaurant employees. Own systems end to end, lead complex projects from design through deployment, improve reliability and correctness, collaborate with product and design, review code, mentor engineers, and deliver scalable backend services that affect employee pay and product revenue.

Build and maintain responsive web experiences, PWAs, and native-feeling mobile apps; design secure APIs and third-party integrations; develop conversational AI bots and support automation; implement ad-tech, segmentation, push notifications, analytics, and A/B testing; and optimize performance, reliability, and uptime. The role requires full-stack development, cloud and DevOps fundamentals, and collaboration in a fast-paced startup.

Lead frontend and full-stack engineering, architect scalable features, integrate APIs and cloud services, optimize rendering and performance, establish engineering standards, conduct code reviews, and mentor developers. Collaborate with product, UX, and backend teams to deliver user-focused software while managing priorities in an ambiguous environment.

Design, build, and maintain AI-powered B2B SaaS products across frontend, backend, and AI. Own projects end-to-end, collaborate with product and design, ensure maintainability, mentor teammates, and inform roadmap and implementation decisions.

The Senior Fullstack Software Engineer will design, implement, and maintain features for Conveyor's SaaS platform, involving both backend and frontend work, while collaborating closely with team members and mentoring juniors.

Develop scalable Java-based software and distributed systems for BILL’s Growth team. Improve subscription, monetization, pricing, packaging, and customer upgrade or downgrade experiences. Build AWS-based SaaS applications, design SQL and NoSQL databases, implement CI/CD pipelines, and apply generative AI to software engineering. Collaborate with product managers and cross-functional engineering teams to drive user growth, revenue, and feature engagement.

Build and ship frontend features for a financial marketplace using React and Next.js. Collaborate with product, design, and backend engineers; contribute to architecture, component design, code quality, tooling, and the shared component library. Own work from design through delivery, participate in pairing and code reviews, and use AI-assisted development tools thoughtfully.

Lead development of scalable Java backend applications and high-availability cloud services. Design architectures, REST APIs, databases, caching systems, and distributed session infrastructure. Mentor engineers, drive technical initiatives, address performance and scalability challenges, and uphold quality and automation practices for endpoint management products.

Develop and administer STIBO STEP solutions supporting enterprise master data management initiatives. Responsibilities include designing workflows, WebUI interfaces, attributes, validation rules, and integrations; ensuring data quality, governance, and platform performance; troubleshooting complex issues; supporting production operations and SaaS upgrades; and collaborating with Product, stakeholders, and engineering leadership. The role also includes mentoring engineers, estimating work, driving delivery, and implementing product, vendor, and customer data governance frameworks.

Build and ship end-to-end features for Dover's marketplace and ATS. Propose product ideas, implement designs, launch, iterate in production, and collaborate closely with a small engineering team to move quickly and maintain high quality.

Unpaid software engineering internship focusing on full-stack web development with TypeScript, Next.js/React and Node/Express. Work on front- and back-end features, responsive UI with Tailwind, animations with Framer Motion, PostgreSQL and MongoDB integration, REST APIs, microservice-based architecture, code reviews, debugging, and product planning in a remote-first startup.

Lead backend engineering strategy for Affirm’s international Identity team. Design and launch highly available distributed systems supporting KYC, user lifecycle management, and identity decisioning. Drive technical planning, cross-functional collaboration, operational excellence, monitoring, testing, and on-call readiness. Establish engineering quality standards, influence architecture, mentor team members, and deliver scalable systems using Python or Kotlin, AWS, MySQL, Spark, and Kubernetes.

Senior Software Engineer responsible for designing, developing, testing, and releasing scalable full-stack features for Huntress’s Core Platform. The role owns complex projects end to end across frontend, backend, databases, and infrastructure; promotes code quality through testing, reviews, and pairing; breaks down epics into milestones; contributes technical solutions; and mentors engineers. The position requires extensive Ruby on Rails and full-stack experience, plus familiarity with Linux infrastructure, databases, external APIs, Agile practices, and responsible AI-assisted development.

Build and operate enterprise-grade backend microservices, data pipelines, integrations, and internal tools for finance automation. Productionize AI and agentic workflows, design event-driven systems across billing, ERP, Salesforce, and data platforms, and develop lightweight operator UIs. Own technical strategy, architecture, reliability, auditability, permissions, and enterprise controls including SOX and PCI requirements. Collaborate with Finance, Security, Compliance, and Audit teams to deliver scalable automation solutions.

Work directly with the founder to design and build core product features: integrations that pull license data, automation to file renewals/applications, data cleaning with AI, dashboard and alerting UX, and establish engineering practices for testing, deployments, and security. Term contractor role with potential conversion to full-time based on performance.

Build and maintain secure, scalable APIs and infrastructure for an AI-powered fintech platform. Develop features across the stack, integrate third-party APIs, deploy infrastructure with Terraform, apply compliance and security practices, and support customers as a technical point of contact. The role involves close collaboration with the CTO in a greenfield, early-stage startup environment.

Develop and operate backend systems supporting post-transaction processing for Affirm Card. Break down projects, write tested and extensible code, collaborate with product and engineering teams, monitor system health, troubleshoot issues, participate in on-call support, and contribute to code reviews and team development.

Design, develop, test, and maintain backend systems and APIs for ingesting, processing, and routing large-scale telemetry data. Own end-to-end features, contribute to architecture and internal tools, write automated tests, participate in on-call/support rotation, and collaborate with cross-functional teams to deliver scalable, high-performance distributed systems.

Designs, develops, tests, troubleshoots, documents, and maintains software applications throughout the project lifecycle. Responsibilities include coding, database and system administration, performance testing, debugging, software upgrades, requirements documentation, user support, vendor coordination, and collaboration with analysts, administrators, and engineers. The role also provides guidance to junior development staff and supports cross-departmental projects.