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Senior Ruby/Rails Backend Developer

Engineering | San Francisco, CA | Full Time and Temp to Perm

Job Description

About CrowdFlower...

CrowdFlower is the essential human-in-the-loop platform for data science teams. CrowdFlower helps customers generate high quality customized training data for their machine learning initiatives and to automate business processes with easy-to-deploy ML models and integrated human-in-the-loop workflows. The CrowdFlower platform supports a wide range of use cases including self-driving cars, intelligent personal assistants, medical image labeling, content categorization, customer support ticket classification, social data insight, CRM data enrichment, product categorization, and search relevance. 

Headquartered in San Francisco and within walking distance to some of the best cafes, restaurants and social activities in the city, CrowdFlower has a diverse and experienced team and are backed by Canvas Ventures, Trinity Ventures, Industry Ventures, Microsoft Ventures, and Salesforce Ventures. For more information, visit

We are looking for smart, innovative people to help us build scalable, resilient and responsive systems, working with our team based in either San Francisco’s Mission District or Sacramento California. 

The Ideal Candidate

You are an experienced application developer who knows how to design and implement scalable, resilient, secure and responsive systems. You like to work with different technologies and are passionate about learning new things. You take pride in designing elegant, simple solutions to challenging problems, whether updating legacy systems or creating new micro-services. You will help ensure we continue to evolve and keep our edge as a world-class development team building great products. You are looking to join a team where you can make a difference while also being challenged to improve your own skills.


  • Participate in designing and developing robust, scalable systems with modern design patterns in a services oriented architecture.
  • Take the initiative to share your skills & knowledge with other members of the team and learn from them in return. Collaboration is key in producing quality software.
  • Demonstrate ownership and pride in your work and encourage others to do the same.
  • Analyze and improve existing systems and offer go-forward suggestions to enhance scalability, resiliency and performance.
  • Promote best practices for writing maintainable, well-tested code within a scrum based agile process.
  • This is a purely backend role so UX and Javascript experience is not required

Skills & Experience:

  • Minimum of 5 years of work experience with at least 1 year of backend Ruby/Rails development. Experience with other programming languages such as Java / Spring Boot is a plus.
  • Experience with a range of data stores, including relational (SQL), column-oriented and key-value stores such as Postgres, Memcache, Redis and RedShift.
  • Knowledge of professional software engineering best practices for the full software development life cycle, including coding standards, code reviews, source control management, agile development, build processes, testing, and operations.
  • Experience with the following technologies will be a definite asset:
    • AWS platform and its many components (S3, API Gateway, etc)
    • Microservices architecture
    • Swagger and RESTful API design
    • Docker containerization, Kubernetes orchestration

CrowdFlower offers an attractive total compensation package including outstanding benefits and stock options.