Peoplebox.ai is a fast-growing, YC-backed start-up building an AI-powered Performance Management platform. We help modern companies drive real business outcomes by aligning people, goals, and feedback — all inside everyday tools like Slack, Teams, and email. Responsibilities : • Build and maintain MVC-based Ruby on Rails applications and RESTful APIs, ensuring code is clean, modular and well-documented. • Implement and optimize asynchronous jobs using Sidekiq and/or Delayed Job to support long-running or high-volume tasks. • Leverage Redis for caching, session storage and job management to deliver fast, responsive user experiences. • Design efficient schemas, write optimized SQL (MySQL or PostgreSQL), and apply indexing and normalization best practices. • Architect and iterate on scalable, decoupled systems—whether monolith or microservices—balancing performance, reliability and maintainability. • Define, document and consume secure, versioned RESTful endpoints that serve both internal and external clients. • Write and maintain unit/integration tests (RSpec or Minitest), and contribute to CI/CD pipelines for automated builds, tests and deployments. • Partner with product managers, designers and front-end engineers to translate business requirements into technical solutions. Provide clear, proactive updates on progress, challenges and trade-offs. Requirements : • Ruby on Rails, Python: 5+ years of production-grade experience, strong grasp of MVC conventions and Rails best practices. • Background Jobs: Hands-on with Sidekiq and/or Delayed Job for asynchronous processing. • Redis: Proven use for caching, session storage, pub/sub or job queues. • Relational Databases: Expert in MySQL or PostgreSQL—schema design, indexing, query optimization. • API Development: Comfort designing, documenting and securing RESTful APIs. • System Design: Ability to decompose complex problems, build modular services (microservices a plus) and make trade-off decisions. • Version Control: Daily use of Git, collaborating via GitHub or GitLab. • Containerization: Familiarity with Docker for development and production consistency. • Cloud Services: Working knowledge of AWS (e.g., EC2, S3) or similar. Nice-to-Have : • Proven microservices or event-driven architecture experience. • Experience with infrastructure as code (Terraform, CloudFormation). • Previous work in fast-paced, product-oriented start-ups.