Top Senior Software Engineer Jobs in Seattle, WA

Design, implement, and operate critical, highly scalable backend services (identity, friend graph, persistence). Collaborate across teams, ensure availability, scalability, operational excellence, and cost management. Build, test, debug, and participate in incident resolution while leveraging AI tools to accelerate development and maintain secure, production-ready code.

Design, implement, and operate scalable ads delivery backend services. Own serving-time systems, collaborate with Product/ML/Infra, ensure availability and efficiency, use observability and automation, and apply AI-assisted workflows to ship production-quality code and optimize platform architecture.

Design and implement scalable backend systems for search and conversational AI. Build and productionize services leveraging LLMs, embeddings, and vector search. Lead architecture, mentor engineers, drive cross-team initiatives, and improve developer productivity and operational excellence.

Design and build large-scale systems for managing merchandise, ensuring data synchronization across platforms, and collaborating with cross-functional teams to support enterprise-level sellers.

The Software Engineer will enhance the structured data storage layer in Superhuman Docs, ensuring database reliability, performance, and correct data handling under varying workloads. Responsibilities include improving table management, server-side query planning, and collaborating on formula and sync processes.

Lead an Agile team to design, implement, test, and maintain an enterprise simulation framework across Windows/Linux. Drive CI/CD, unit testing, documentation, customer support, debugging, and collaboration with domestic and international partners for simulation, HIL, and cloud environments.

As a Video Engineer at Whatnot, you'll enhance the platform's video services, develop seller tools, and implement innovative video strategies to improve user engagement and experience.

The Senior Software Engineer will design and support Kubernetes infrastructure, develop applications in Go, and enhance platform reliability, performance, and observability in CoreWeave's AI-focused environment.

As a Senior Software Engineer, you'll develop scalable distributed systems for Chewy's Sponsored Ads platform, mentor engineers, and enhance engineering excellence.

The Back-End Engineer will design and build core platform services, operate production services, and work on AI-powered features while collaborating with cross-functional teams and mentoring junior engineers.

As a Front-End Software Engineer, you will build AI-powered interfaces, tackle complex design problems, and collaborate across teams to enhance user experiences. Responsibilities include mentoring, implementing responsive UI, and engaging with AI technologies.

The role involves leading the design and development of software engineering tools for the E-7A program while enhancing DevSecOps operations. Responsibilities include collaborating with teams, providing support, and ensuring software environments are maintained.

As a Fullstack Software Engineer, you'll design, develop, and maintain scalable frontend and backend systems while collaborating across teams.

As a Billing & Analytics Software Engineer, you'll design and maintain the billing pipeline, integrate billing systems, and develop customer-facing analytics dashboards to support revenue recognition and operational observability.

Develop and implement cloud-based microservices for supply chain workflows. Ensure scalability, reliability, and performance of backend services, while collaborating across engineering teams and establishing API contracts.

Lead design and delivery of scalable customer-facing features, services, and APIs that process real-time data and AI-powered insights. Build web experiences, contribute to LLM/AI workflows, ensure reliability through observability and rollout practices, and collaborate cross-functionally with Product, Design, ML, and platform teams.

Design and re-architect the Identity systems at Dropbox to support multi-product capabilities, mentor junior engineers, and ensure software excellence.

Lead architecture, modernization, and development of Group Insurance applications. Modernize mainframe monoliths into Java microservices and micro-frontends on cloud, mentor distributed Agile teams, collaborate with enterprise architecture, product owners and infrastructure, and enable test automation and integrations. Approximately 10% domestic travel.

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.

Lead design and implementation of the payment and clearinghouse platforms powering Headway's revenue flows. Build fault-tolerant, observable integrations (Stripe, Plaid, payers), create abstractions for adjacent teams, mentor engineers, and write high-impact code to ensure reliability, throughput, and correct reconciliation of transactions at scale.

Design and build reliable backend services powering clinical data, insurance billing, patient-facing infrastructure, and financial ledger systems. Scale high-integrity systems requiring idempotency, strong consistency, and pragmatic AI integration to automate provider workflows and enable personalized patient experiences.

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.

Lead frontend-leaning full-stack implementation work for carrier and enterprise integrations: architect reusable UI and API layers, author RFCs, guide technical delivery, enforce testing and security best practices, and partner with cross-functional teams to scope and ship production integrations.

Build and own Eve's marketing site and GTM engineering stack: integrate and optimize external tools, design AI agents for sales and marketing, implement webhooks and middleware to sync product/CRM data, and create programmatic campaigns and internal tools in partnership with Marketing, Sales, RevOps, and Product to drive growth and automation.

As a Senior Software Engineer in Trust & Safety, you'll analyze threats, design systems for abuse detection, and collaborate with teams to implement scalable defenses.