Work at Sempi
Marketplace Integrations Engineer (contract-based)
We're looking for a contractor to develop and maintain our marketplace integrations. This role focuses specifically on building robust, maintainable connections with various marketplace platforms, including those with limited or no official API documentation.
About Sempi
We're building a platform that makes reselling valuable items simple. Our software lets you sell across multiple marketplaces at once, making reselling easier and promoting sustainability through second-hand sales. We're a small, venture-backed team in Berlin. We bring experience from both successful startups and major tech companies, and we're ready to grow thoughtfully.
Key Responsibilities
Design and implement new marketplace integrations
Reverse engineer marketplace APIs where necessary
Build resilient error handling and retry mechanisms
Document integration patterns and potential pitfalls
Monitor and maintain integration performance
Required Experience
Must Have
Strong experience building and maintaining production API integrations
Proven track record of reverse engineering web applications and APIs
Experience with Ruby on Rails
Experience with web scraping and automated browser testing when needed
Experience building error-resilient systems
Nice to Have
Experience with rate limiting and request optimization
Solid understanding of authentication methods and API security
Familiarity with e-commerce or marketplace platforms
Experience with Selenium, Puppeteer, or similar tools
Knowledge of API monitoring and observability tools
Experience documenting complex technical systems
Project Structure
Remote work
2-3 month initial engagement
Potential for ongoing relationship
Flexible hours, results-focused collaboration
Direct communication with technical co-founder
If you don't check all the boxes but think you'd be a great fit, we'd still like to hear from you.