Senior Backend Software Engineer at Fleek

You will join the Growth squad to build the transaction layer for the world’s first digital supply chain for secondhand fashion. Reporting to the CTO (ex-Google, Postmates), you will integrate fine-tuned AI models into a B2B marketplace handling 500,000+ items monthly, turning manual trades into a structured, searchable global inventory layer.

• Architect and scale backend systems in Node.js and TypeScript to handle the transition from 500k to millions of unique items per month.
• Own the end-to-end ecommerce journey, including discovery, search, checkout, and complex international payment and credit systems.
• Collaborate with AI and data teams to bridge the gap between classification engines and the core marketplace product experience.

• 6–10 years of professional backend experience with strong fundamentals in system design and API architecture at high-growth consumer or marketplace companies.
• Proven product engineering mindset with a history of shipping end-to-end features in fast-paced, ambiguous startup environments.
• AI-forward builder who uses tools like Cursor or Copilot as a force multiplier and has experience deploying AI capabilities at scale.

• Work at the intersection of circular economy and proprietary AI, using a fine-tuned model (not a GPT wrapper) to digitize a $350B industry that has never had technology.
• Massive financial backing with ~$50M raised from elite investors including a16z, Y Combinator, and HV Capital, plus advisors from Depop and Shopify.
• High-velocity environment where you will see immediate impact, helping save millions of garments from landfills while the company triples in size year-on-year.