Senior Full Stack Blockchain Developer Jobs in Seattle, WA

We are seeking an experienced Senior Full Stack Engineer – Commerce AI with a strong background in full-stack engineering and applied AI/LLM systems to support the client's Commerce AI team. This role sits at the intersection of technical innovation and guest experience, helping shape the strategic direction of AI-powered commerce solutions.

The successful candidate will architect, build, and deploy AI-native applications that directly impact high-traffic booking flows, dynamic pricing models, and personalized guest experiences, blending deep traditional full-stack engineering with hands‑on orchestration of Agentic AI systems using modern LLMs and integration frameworks.

This role is ideal for a highly autonomous, detail‑oriented senior individual contributor who is comfortable driving complex system design, working across dual-cloud environments, and delivering AI solutions within a high‑traffic, revenue‑generating e‑commerce environment.

Location: Seattle (hybrid preferred) or remote covering PST time zone

Contract Length: 1 year (extension and conversion option)

Rate: $75-$90/h

• Design, build, and scale secure, AI-native applications that enhance the digital storefront, optimize revenue, and personalize the guest journey.


• Implement advanced Agentic AI workflows, integrating with leading LLMs (Gemini, OpenAI, Anthropic) to build autonomous systems for planning, dynamic merchandising, and guest support.


• Leverage the Model Context Protocol (MCP) framework to seamlessly and securely connect AI models with enterprise booking engines, CRM systems, and real-time operational data.


• Write clean, maintainable, high-performance code across the stack utilizing C# (.NET) for high-throughput backend microservices and SvelteKit for dynamic, accessible user interfaces.


• Architect and manage cloud infrastructure across Azure and GCP, ensuring optimal deployment, latency reduction, scaling, and cost efficiency of AI workloads in high‑traffic e‑commerce environments.


• Drive complex system design discussions, establish technical guardrails, and ensure strict adherence to data privacy, AI safety, and enterprise architecture standards.

• 8+ years of professional software engineering experience.


• 3+ years of dedicated experience building and scaling production‑grade AI-native or LLM‑powered applications.


• Deep expertise in C# and the .NET ecosystem for building enterprise‑grade APIs and highly available microservices.


• Proven track record building interactive, performance‑optimized e‑commerce or consumer‑facing web applications using SvelteKit (or advanced Svelte).


• Hands‑on experience deploying and managing production workloads in both Microsoft Azure and Google Cloud Platform (GCP).


• Hands‑on experience working with the Model Context Protocol (MCP) to build secure ecosystem integrations for LLMs.


• Demonstrated experience designing autonomous agents, multi‑agent orchestrations, and complex tool‑use (function calling) paradigms.


• Deep understanding of API integration, fine‑tuning patterns, and Retrieval‑Augmented Generation (RAG) using Gemini, OpenAI, and Anthropic models.


• Strong background in system design, specifically balancing trade‑offs between latency, cost, and accuracy when integrating AI into revenue‑generating e‑commerce flows.


• Proven success as an individual contributor in fast‑paced, agile environments.

• Experience building complex, high‑transaction e‑commerce systems involving dynamic pricing, real‑time inventory management, or high‑scale loyalty programs (travel industry background is a strong plus).


• Experience building complex reasoning pipelines, semantic routing architectures, or custom retrieval logic to supply AI agents with enterprise business rules.


• Knowledge of LLM monitoring, evaluation, and observability tools.

• Post‑secondary degree in Computer Science, Software Engineering, or related discipline.

We are an equal opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, disability status, or other non‑merit factor. We are committed to creating a diverse and inclusive environment for all employees.