Staff Full-Stack Engineer - Data Intensive Web-Applications - Personalization

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Staff Full-Stack Engineer - Data Intensive Web-Applications - Personalization based in Brazil. This is a Staff-level, hands-on engineering role focused on building and operating data-intensive web applications and personalization capabilities. You will develop backend services, APIs, analytical data access layers, and authentication systems that power commercial intelligence and data-driven decision-making. The role combines backend depth with full-stack ownership, allowing you to take features from design through production and into ongoing operation. You will work on distributed systems where performance, reliability, observability, scalability, and cost efficiency are treated as core product requirements. The position sits within a lean team of experienced engineers, with opportunities to influence technical standards through design, code review, pairing, and evidence-based decisions. You will integrate applications with internal services, analytical platforms, and AI or agent-based services while handling complex distributed-system challenges. This opportunity is ideal for a strong technical builder who enjoys owning production systems end to end and using modern engineering practices to deliver high-impact products.