***About Us*** Magalu is one of the largest retail companies in Brazil, recognized for its innovation and digital presence. Magalu's technology team is composed of innovative professionals passionate about transforming digital retail. With a focus on agile and scalable solutions, they develop projects that impact millions of customers. In a collaborative environment, they constantly seek excellence in technology and innovation. **Job Description** **Who We Are and Our Current Moment** At Luizalabs, our mission is to provide intelligent and integrated solutions that revolutionize ultra\-rapid delivery and last-mile logistics. We are building a new generation of software engineering based on **Specification\-Driven Development (SDD)** and **Agentic Engineering**. In this model, the role of the Senior Engineer evolves from a manual code writer to a high-performance system designer. You will be the technical lead responsible for translating complex business and logistics challenges into executable specifications, defining robust guardrails, and orchestrating AI agents (specialized in architecture, development, and testing) to evolve our high-scale platform in **Ruby on Rails**. We are looking for professionals who understand that code is no longer the primary asset but rather a byproduct of impeccable specifications, combining mature traditional software engineering with the pinnacle of AI-assisted development. **Responsibilities and Duties** * **AI\-Native Development and Orchestration:** Execute and orchestrate workflows using multiple AI agents in daily operations to accelerate and ensure the quality of deliveries. * **Technical Specification and SDD:** Translate logistics and high-concurrency problems into clear, complete, and executable specifications through SDDs (*System Design Documents*). * **Building Guardrails \& Harnesses:** Create and evolve automated validation mechanisms (*harnesses*) and technical protections to ensure that AI-generated code meets security, business, and performance criteria. * **Reverse Engineering and Critical Review:** Audit, test, and refactor AI-generated software in the Ruby on Rails ecosystem with a critical eye, ensuring Clean Code standards, resilience, and scalability. * **Platform Evolution at Scale:** Write and refine efficient code for high-availability scenarios, solving complex production issues, performance bottlenecks, and infrastructure optimization. * **Mentorship and Culture Dissemination:** Guide full-stack and junior developers on the team in best practices for software engineering, TDD, and the advanced/efficient use of generative AI tools. **Essential Requirements: AI Applied to Engineering \& GenAI Symbiosis** * Consistent practical experience in using generative AI tools for software development (**GitHub Copilot, Claude Code, Cursor, OpenHands, Devin** or similar). * Solid skills in *Prompt Engineering*, *Context Engineering*, and understanding of *Agentic Workflows* to delegate raw code writing, focusing on governance and logical refinement. * Strong ability in abstraction, decomposition of complex problems, and systemic reasoning. **Software Engineering \& Backend Ecosystem** * Solid and proven market experience in development using **Ruby on Rails** in high-scale production environments. * Deep mastery of backend architecture patterns (Modular Monoliths, Microservices, RESTful APIs, and Object-Oriented/SOLID). * Advanced experience in Rails performance optimization (avoiding N\+1 queries, strategic caching, background jobs at scale with **Sidekiq** or Resque). * Mastery of relational databases (**PostgreSQL/MySQL**), including data modeling and optimization of complex queries. * Practical familiarity with event-based architectures and messaging (**Kafka, RabbitMQ, or AWS SQS**). **Quality, Reliability, and Observability** * Rooted culture of automated testing: mastery of **TDD**, testing frameworks (**RSpec**, mocks, stubs, factory\_bot), and integration/contract tests. * Practical experience with CI/CD pipelines, containerization (**Docker**), and cloud environments (**AWS, GCP, or Azure**). * Experience with monitoring and observability tools (**New Relic, Datadog, Prometheus/Grafana**). **Differentiators** * Previous experience or strong familiarity with *Specification\-Driven Development* (SDD). * Experience in creating or customizing specialized AI agents for engineering tasks. * Practical knowledge in DevOps (Terraform, Kubernetes). * Experience in the Logistics, e\-commerce, or marketplace platform ecosystem. **How We Measure the Success of This Senior Role** Success in this role is measured less by the raw volume of lines of code typed manually and more by the ability to: * Structure high-precision technical specifications and guardrails that allow AIs to produce correct software on the first attempt. * Ensure the security, maintainability, and performance of the Ruby on Rails ecosystem, mitigating the risks of code generated by automations. * Increase the delivery speed (*throughput*) of the squad through the intelligent use of agentic tools. * Multiply technical knowledge within the team, helping to lead the cultural transition to AI\-Native development. **Work Model** We adopt a 100% remote model, providing flexibility while maintaining virtual interaction with the team to ensure effective collaboration and a continuous growth environment. ‘’If you are looking for an environment of growth and challenges, Come be happy’’! Our values unite us, and our differences empower us as a group. More than equality, we seek equity: Here, we have space to be authentic, regardless of gender, ethnicity, race, sexual orientation, religion, or disability.
João Silva
Indeed · HR
João Silva
Indeed · HR
