Empresa: Mazzatech
📍 100% Remote 🌎 Brazil or Argentina 💼 Direct hire by the client About the company Our client is a large fintech company operating in the digital financial services space and in a high-scale technology environment. The company runs critical products with high transaction volumes and strong requirements around availability, security, performance, and continuous evolution. About the opportunity We are looking for a Staff Engineer to join a squad responsible for critical systems related to payment processing , with a strong focus on backend engineering, architecture, and product evolution. The main challenge in this role will be to evolve and scale the current system , ensuring the architecture can support business growth while maintaining stability, performance, and reliability under high transaction volumes. We are looking for someone with solid experience in complex systems architecture , who has led important technical decisions and contributed to the evolution of highly critical products. Beyond mastering specific technologies, this person should be able to understand the current scenario, identify architectural limitations, and propose sustainable solutions for future growth. The role requires a hands-on backend profile with strong experience in Java, Spring Boot, PostgreSQL, Kafka, and AWS , as well as distributed systems, event-driven architectures, and asynchronous processing. It is also important to have the maturity to operate in critical situations , such as production incidents, demand spikes, or scenarios that require fast and high-impact technical decisions. Previous experience with payments, financial systems, fraud, or other transactional environments is highly valued, but not mandatory. We also expect a collaborative profile with strong technical influence , able to work closely with Product, Data, and other Engineering teams, supporting architecture decisions, code reviews, and the continuous improvement of technical standards. Main responsibilities • Lead architecture decisions and highly complex technical initiatives; • Evolve and scale mission-critical backend systems; • Work on solutions related to payment processing and transactional flows; • Develop and evolve applications using Java, Spring Boot, PostgreSQL, Kafka, and AWS ; • Work with distributed systems, microservices, and event-driven architectures; • Ensure application performance, availability, scalability, and reliability; • Investigate and resolve incidents and complex production issues; • Conduct code reviews and promote software engineering best practices; • Provide technical support and mentorship to engineers at different seniority levels; • Collaborate with Product, Data, and other technical teams; • Promote the use of AI applied to software development . Requirements • Solid backend development experience with Java and Spring Boot ; • Experience with PostgreSQL, Kafka, and AWS ; • Strong knowledge of systems architecture ; • Experience with distributed systems and high-scale applications; • Experience with event-driven architecture and asynchronous processing; • Experience evolving or scaling complex products; • Ability to make technical decisions in highly critical and ambiguous scenarios; • Experience with performance, observability, and production troubleshooting; • Knowledge of relational databases, Object-Oriented Programming, and Domain-Driven Design (DDD) ; • Experience with code reviews, technical standards, and knowledge sharing; • High level of autonomy and technical influence; • Practical experience using AI in software development . Nice to have • Experience with payment processing ; • Experience in fintechs, banks, or financial services companies; • Experience with fraud, risk, or decisioning systems; • Experience in high-volume transactional environments; • Experience with Python ; • Knowledge of security, compliance, and auditability requirements. Profile we are looking for We are looking for someone with strong technical seniority , solid architecture experience, and the ability to work hands-on in the evolution of complex systems. The ideal profile should be comfortable operating under pressure and in critical scenarios, able to learn and adapt quickly, and demonstrate a collaborative mindset with the ability to influence technical decisions without relying on formal management authority. The opportunity is open to professionals based in Brazil or Argentina . For candidates based in Brazil, English proficiency or willingness to communicate in Spanish is important.