**Are you a curious, collaborative person who enjoys sharing knowledge while tackling real technical challenges? Then this opportunity is for you!** We are looking for a **Senior Backend Developer** to work with a global technology client present in multiple countries and delivering high-traffic, high-impact digital products. You will join a newly formed team, spun off from a larger structure, operating within a highly complex chat context. This person will play an active role in analyzing, suggesting, and implementing improvements—with a focus on reducing complexity, advancing architectural evolution, and increasing solution reliability. **Responsibilities and Duties** **In your day-to-day work, you will encounter the following activities:** Proactively and autonomously develop backend solutions; Analyze existing architectures, identifying improvement points and simplification opportunities; Develop and evolve backend services focused on scalability, fault tolerance, and high availability; Implement integrations between systems, APIs, and asynchronous workflows; Work with messaging systems, evaluating processing strategies, reprocessing, and delivery guarantees; Work with API integrations via REST, SOAP, and WebHooks; Contribute to observability, monitoring, and system reliability practices; Actively participate in agile ceremonies, technical refinements, and solution design; Collaborate with various technical teams in an agile environment. **Requirements and Qualifications** **Check below what you’ll need to succeed in this opportunity!** **REQUIRED KNOWLEDGE** * Python, with experience in automation, workers, integrations, scripts, observability, and internal tools; * Elixir, focusing on: concurrent, fault-tolerant, and highly available systems; OTP usage (GenServer, Supervisor, ETS); processes and scalability; * Node.js; * Kotlin, for backend service development, messaging integration, performance, and typing; * Experience with MongoDB; * Experience with PostgreSQL; * Proficiency in SQL; * Development and integration of REST and SOAP APIs; * Implementation and consumption of WebHooks; * RabbitMQ, including: conceptual differences between queues vs logs, consumer groups, ordering and reprocessing; gradual migration strategies, dual-write/bridge, observability, and use of DLQ/DLT; knowledge of delivery guarantees (at-least-once / exactly-once, with realistic expectations); * Kafka; * Experience with Agile Methodologies; * Application of SOLID principles. **DESIRABLE KNOWLEDGE** * Experience with XMPP / Jabber; * Jenkins; * Git and GitLab CI; * Docker; * Kong, including: * Configuration of routes, plugins, authentication, rate limiting, observability, and policies; * Grafana for monitoring and metric visualization. **Additional Information** **Deliver IT will leave its mark on this project—and we invite you to be part of this journey!** We have a light, relaxed, collaborative, and diverse culture, as well as an enriching environment filled with many top-tier colleagues across various domains and plenty of challenges. Here, you’ll find innovative projects, strong connections, and abundant knowledge exchange! All our positions follow the CLT employment model with 44 hours per week. **CHECK OUT OUR BENEFITS** * Work Mode: 100% Remote * VA and/or VR * Well-being Program: psychological support, legal support, social support, financial support. * Health Insurance and Dental Insurance * Life Insurance * Wellhub * Monthly Workshops * Partnerships offering discounts: Sucesu, Target Trust, Sesc, and Seprorgs * Anniversary Bonus (company anniversary) * Referral Bonus (for successfully hired referrals) The technology universe is vast—just like our career opportunities and the reasons you should become Deliver IT. Discover and build your future with us. **VALUES WE DELIVER TO YOU** **IT IS TECH** Here, we use technology to strengthen relationships between people and businesses. **IT IS COLLABORATION** Our collaborative spirit fosters a productive, relaxed, transparent, and human-centered environment. **IT IS RESPONSIBILITY** We know that innovation requires responsibility—only then can we enjoy the freedom and autonomy needed to create groundbreaking solutions. **IT IS OPPORTUNITIES** We are valued for our capabilities and receive the necessary encouragement to develop our talents.