Top Full-Stack Engineer Jobs in Seattle, WA

The Full-Stack Software Engineer will enhance user interfaces, APIs, and develop features for AI applications while collaborating with teams and ensuring code quality.

As a Senior Full-Stack and Platform Software Engineer at mabl, you will develop features for an AI-powered test automation platform, enhancing user experiences, designing APIs, and optimizing data pipelines while collaborating with cross-functional teams.

As a Full Stack Engineer, you will lead UI and backend teams to design, develop, and maintain high-performance web applications while providing technical guidance.

As a Senior Software Engineer at Vanta, you'll lead complex projects, mentor engineers, and contribute to building emerging products and features across the Product Platform.

As a Fullstack Engineer, you will develop and enhance user experiences for members and providers at Thyme Care, collaborating with teams to deliver scalable products.

As a Full-Stack Engineer at Afresh, you'll develop applications to enhance grocery store operations and optimize the fresh food supply chain, while collaborating with product teams and driving new feature development.

Lead design and delivery of production-grade AI-powered full‑stack features, integrating LLMs, agent systems, vector databases, and RAG. Build scalable frontend (React/Next.js) and backend (Python/Go) services, cloud-native infrastructure, CI/CD pipelines, and observability. Influence architecture, mentor teams, and drive technical vision from 0-to-1 through ongoing ownership.

Volunteer Principal Full Stack Engineer to lead and contribute across frontend and backend (React/React Native, Node.js, MongoDB). Own feature development, mentor engineers, collaborate with product/design, ship scalable code, and support CI processes. Must commit 4+ hours weekly and attend a weekly standup; first task includes launching a fundraising campaign.

Lead full-stack modernization of DHS ICE systems by analyzing legacy workflows, designing scalable platform-based applications, building backend services and APIs, developing React-based front ends, integrating with legacy systems (Palantir target), supporting full SDLC, troubleshooting across layers, and collaborating with stakeholders to simplify and translate mission-critical functionality.

Build end-to-end AI-powered video creation features across frontend and backend: implement rich multimedia interfaces, LLM-powered conversational experiences, integrate third-party AI APIs, deploy production-ready systems, and optimize performance and reliability.

The Full Stack Developer designs and develops scalable applications for biopharma clients, collaborating with cross-functional teams to integrate data and user interaction.

Build and scale an agentic AI stack for healthcare revenue cycle: implement voice AI pipelines, LLM orchestration, integrations with EHRs/RCM systems, real-time analytics, dashboards, and production-grade full stack features working closely with founders and customers.

The Senior Fullstack Engineer will build and manage enterprise authentication systems, improve user session management, ensure security compliance, and support internal API usage across services, while enhancing performance and reliability.

Staff full‑stack engineer to own cross‑stack architecture and deliver high‑impact features quickly. Work on a React/React Native app and Node.js/TypeScript and Go backends, set technical direction, mentor a small squad, contribute to the open AT Protocol ecosystem, and integrate agentic AI tooling to boost team productivity.

The Full-Stack Developer will optimize web applications using Next.js and React, handle server-side logic with Vercel, and manage Postgres SQL databases in a remote, agile environment.

The Fullstack Developer will create and maintain scalable web applications using React and Node.js, design APIs, and optimize PostgreSQL databases while collaborating with teams and ensuring code quality.

The Full Stack Engineer will design, implement, and improve shared platform capabilities, collaborating to ensure high-quality, reliable software solutions while experimenting with modern technologies.

Lead development of an AI-enabled Ethereum Layer 2 platform: build front-end and back-end systems, deploy and optimize AI models, create data pipelines, collaborate on model training, and contribute to product innovation and other company projects.

Lead customer-facing architecture and development of scalable, cloud-native AWS applications. Drive design discussions, migrate monoliths to microservices, implement serverless and container solutions, advise on AWS best practices, and influence developer-focused product and platform strategy.

Lead technical engagements to architect and build scalable, cloud-native AWS applications using serverless, containers, and microservices. Migrate monoliths to microservices, advise on AWS best practices, influence infrastructure and product strategy, and work directly with customers and cross-functional teams.

As a Staff Backend Engineer, you'll develop new product experiences, lead technical capability investments, and mentor engineers in backend development.

Build and maintain end-to-end product features across frontend, backend, and databases. Design APIs, authentication, data models, integrations, and AI-assisted workflows. Ship production-ready SaaS components, debug across the stack, improve reliability and performance, and collaborate on product and architecture decisions in an early-stage startup.

Design and build the Command & Control frontend and full-stack features for large heterogeneous UAV swarms. Develop distributed, real-time infrastructure tolerant of intermittent communications, implement UI concepts for telemetry, sensors, scheduling and data links, own features end-to-end, and maintain strong CI/CD, QA, and DevSecOps practices.

Support and debug .NET applications (2–4 years experience). Analyze application logs and perform troubleshooting in a clean room/customer R&D lab. Candidate will attend a client interview as part of external hiring.

The Fullstack Engineer will develop and enhance a VA patient portal using Ruby and React, focusing on user experience, performance, and security, while collaborating with a cross-functional team in a remote setting.