Senior Software Engineering - Machine Learning

Senior Software Engineer (Search & Personalization) Location: Seattle, WA Type: Full-Time | Engineering

ABOUT BUYWANDER BuyWander is rebuilding the $850B retail returns industry. We take chaotic truckloads of returned goods and transform them into a fast, fun, treasure-hunt shopping experience powered by AI, real-time auctions, and local pickup.
We’re not just building a marketplace. We’re building a daily habit.
THE ROLE We are looking for a highly product-minded Senior Software Engineer to own our Search and Personalization experience.
With the rapid advancement of AI coding agents (like Claude Code and Cursor), the way we build across the stack has completely changed. We aren't hiring you to spend your days writing boilerplate UI components. You will partner with our Data & AI team to take raw recommendation models and turn them into lightning-fast, highly personalized consumer experiences.
Blend rules-based logic with ML-driven recommendations to ensure the right weird, unique, or high-value item hits the exact right bidder at the right time.
Own our core search infrastructure (Elastic Cloud / Pinecone).
You don't just ship features; You will design the A/B testing framework for our search ranking changes.
AI-Assisted Product Development
Use modern AI coding tools to rapidly wire your backend search APIs into our Vue/Nuxt frontend.
Focus your deep thinking on system design, database queries, and user flows, while leveraging AI agents to accelerate UI execution.
You will have the autonomy to design the search logic, test the algorithms, and ship the product experience that solves that problem. If you love building systems that directly drive user addiction and marketplace revenue, let's talk.

Competitive Salary and Performance-based Bonuses

• Meaningful equity in a company attacking a massive market, for a brand that can become nationally recognized
• Health, Vision & Dental Insurance
• The Tech Stack: Deep backend proficiency (we use C#/Python/FastAPI) and a solid understanding of modern frontend frameworks (we use Vue/Nuxt/Vercel).

Proven experience tuning search engines (Elasticsearch, Algolia, or OpenSearch) and familiarity with modern Vector databases (Pinecone).
The Modern Workflow: You are highly proficient in using AI developer tools (Copilot, Cursor, Claude) to multiply your output.

We believe a range of skills, perspectives, and experiences strengthens our team and supports better outcomes for our employees and customers.