Top Full-Stack Engineer Jobs in Seattle, WA

Design, build, and modernize full-stack, cloud-native applications and integrations. Implement REST/GraphQL APIs, microservices, CI/CD, testing, and AI/ML/LLM features. Collaborate with cross-functional teams, mentor peers, and ensure reliable production delivery through observability, automation, and data-driven validation.

As a Fullstack Engineer, you'll design, build, and operate web applications, collaborating with product teams and mentoring peers while ensuring best practices in coding and system architecture.

Design and build tools and automations to deploy and manage CrowdStrike's cloud infrastructure. Collaborate with cross-functional partners to deliver reliable full-stack solutions using React and Go, integrate REST/GraphQL APIs, implement CI/CD and automated tests, emphasize security and documentation, and leverage AI to improve workflows and decision-making.

Build and own end-to-end full-stack features across backend services and user-facing applications. Contribute to system design, reliability, performance, observability, and engineering practices while collaborating with product and design.

Senior full‑stack engineer building customer‑facing web, mobile, and backend systems to grow US remittance business. Lead technical design, deliver scalable, observable services, use AI tools, mentor teammates, participate in on‑call rotation, and collaborate with product, design, and analytics to improve high‑value send experiences.

Design, build, and optimize full-stack mobile and desktop web applications. Implement user interfaces, contribute to shared libraries, log and analyze metrics, use AI tools to accelerate development, and maintain high standards for code correctness, security, testing, performance, and scalability.

As a Site Reliability Engineer focusing on frontend performance, you build infrastructure for self-service performance monitoring, optimize AI operations, and architect resilient systems for high-traffic applications.

Build end-to-end fullstack features for a mental healthcare platform: design APIs and UIs, manage clinical and practice-management systems, integrate AI capabilities, and own product outcomes from schema to frontend.

Headway seeks a Staff Fullstack Engineer to own end-to-end product work across frontend and backend. You’ll build practice management, patient/provider engagement, AI-enabled clinical systems, onboarding, growth tools, and platform foundations. The role requires technical leadership, cross-functional strategy, mentoring, and shipping scalable, reliable systems in a complex healthcare domain.

Design, develop, test, and maintain resilient, high-performance checkout services. Contribute to API and data modeling, ensure operational reliability (monitoring, alerting, CI/CD), troubleshoot production incidents, collaborate with product and design, and integrate AI/ML-driven solutions to improve outcomes.

Lead full‑stack design and delivery of customer‑facing web and mobile features across frontend and backend systems. Own architecture, ship reliable and observable services, mentor engineers, drive process and cross‑team designs, participate in on‑call rotation, and collaborate with product, design, and analytics.

Modernize a large fintech platform by building NestJS services and Next.js UIs, migrate transactional data to relational schemas, write comprehensive tests, identify and fix legacy problems, design scalable solutions that coexist with legacy systems, and use AI tooling responsibly to increase engineering velocity.

The role involves solving complex technical problems as a full-stack engineer, optimizing front-end performance, and collaborating closely with designers to enhance user experiences. Responsibilities include code and design reviews, documentation, and a strong emphasis on accessibility and using AI tools to improve workflows.

Build and maintain full-stack systems for user and access management: design/consume GraphQL/REST APIs, implement high-scale backend services (Java/C#), and create complex React frontends. Work cross-functionally with design and product, translate requirements into data models and APIs, participate in on-call rotation, lead incident reviews, and improve security and observability across microservices.

Build scalable, performant frontend applications using React.js and TypeScript, contribute to backend services in Java/Kotlin, design APIs and data models, collaborate with product and partner teams, own components and production reliability, write secure tested code, and integrate AI/ML-enabled solutions to improve advertising platform capabilities.

Join a small team to improve a tech product aimed at upskilling users in MENA, working with JavaScript and Node.js in a collaborative remote environment.

Build and operate privacy-preserving, high-traffic search services. Implement full-stack features, shape architecture, address tech debt, deploy and monitor services, participate in on-call rotation, and collaborate across product and engineering to release frequent updates.

As a Full-Stack Engineer at Superhuman, you will develop core product features, infrastructure, and collaborate with teams to enhance user experience, focusing on both front-end and back-end services.

The role involves designing and building scalable backend services and APIs to enhance the customer post-transaction experience, ensuring reliability and performance through collaboration with various teams.

As a Fullstack Software Development Engineer, you will build reliable features for high-value customers, collaborate across teams, and mentor juniors while ensuring system performance and availability.

Designs, develops, and troubleshoots secure, scalable backend services and APIs. Produces architecture artifacts, analyzes large datasets for improvements, applies CI/CD and secure SDLC practices, mentors peers, and uses enterprise-authorized AI-assisted tools to improve code quality and delivery.

Lead design, build, and run secure, scalable backend services and APIs (Python/Django/FastAPI). Automate network infrastructure and provisioning, improve reliability via observability and automation, lead system design, mentor engineers, enforce CI/CD, security, and AI-assisted development best practices, and partner across teams for vendor evaluation.

Build and operate high-throughput backend services, scalable APIs, pricing engines, and data models for insurance and fintech products. Lead cross-team initiatives, launch 0→1 products, improve system reliability and performance, troubleshoot distributed systems, and participate in quarterly on-call rotations.

Build and integrate systems for a maritime AI platform. Engage with customers on-site, optimizing data processing and application performance, while ensuring code quality and correctness.

Develop and implement full-stack applications in .NET and Azure, collaborate with teams, provide technical guidance, and ensure high-quality standards.