Job Summary: This role involves leading the technological transformation through AI-first solutions, migrating legacy systems, and collaborating with global teams in a fast-paced environment. Key Highlights: 1. Lead technological transformation with AI-first solutions 2. Pioneer legacy system migration to modern platforms 3. Collaborate globally on high-impact climate tech projects We are specialists in **technological transformation**, combining human expertise with AI to build scalable tech solutions. With more than 8,000 CI\&Ters worldwide, we have formed partnerships with over 1,000 clients throughout our 30-year history. Artificial Intelligence is our reality. **Important**: If you reside in the Metropolitan Region of Campinas, your physical presence at our city offices is mandatory, per our current attendance policy. **Description** **ABOUT THE ROLE** At 3Degrees, we are transitioning from legacy proprietary systems to an AI\-first, enterprise\-grade technology platform. We are looking for a Full Stack Engineer to lead the automation of our Receipts Management process, a mission\-critical initiative involving the migration of legacy data to ION’s Carbon Zero platform. You will be a founding member of an agile unit dedicated to decommissioning 17\-year\-old systems and replacing them with high\-performance, integrated solutions. In this role, you will collaborate with our US\-based teams to build "Callisto," our internal data management platform, ensuring straight\-through processing (STP) for environmental commodities. This is a high\-impact opportunity to apply modern engineering standards and AI\-assisted development to solve complex climate tech challenges at startup velocity.**WHAT YOU'LL DO** **Legacy Migration \& Integration:** Lead the transition of core trading functions from Legacy application to the ION’s Carbon Zero platform, focusing on receipt processing automation across \~40 global registries. **Full Stack Development:** Build and maintain the Callisto UI using React and TypeScript, while developing robust back\-end business logic and APIs in C\#/.NET Core or Python. **Registry Automation:** Develop and support integrations with external EAC (Environmental Attribute Certificates) tracking systems via APIs or AI\-enabled RPA functionality. **AI\-First Execution:** Actively use AI\-assisted coding tools (e.g., Cursor, Claude Code, GitHub Copilot) to accelerate development speed and maintain high code quality. **Cross\-Functional Collaboration:** Partner with US\-based technical leads and business stakeholders to map integration touchpoints across Salesforce, NetSuite, and our operational databases. **ABOUT YOU** You are a versatile builder who thrives in a fast\-paced, "AI\-First" engineering environment. You possess a strong balance of frontend craft and backend rigor, with a specific interest in environmental markets and decarbonization. You are comfortable navigating legacy architectures while architecting modern, scalable alternatives that leverage automated workflows. 8\+ years of experience in C\#/.NET/Python development and React/TypeScript frontend design. Advanced database skills (Azure SQL, Managed Instances) with the ability to analyze and optimize complex schemas. Professional\-level English proficiency (C1\+) with the ability to communicate complex technical decisions to US\-based stakeholders. A "product mindset" with the ability to move from prototype to production in 6–8 week cycles. Availability to maintain high overlap (at least 6 hours) with US Pacific Time (PT) working hours. Demonstrated experience using AI tools (LLMs, agentic frameworks) to accelerate your personal development workflow. **HOW WE DEFINE SUCCESS****Within the first 30 days:** Gain a firm grasp of the "Callisto" architecture, the ION Carbon Zero roadmap, and the specific data structures within the legacy SQL trading environment. Build strong cross\-functional relationships with US\-based technical leads and understand the agile unit's communication and deployment cadences. Successfully clear 3\-5 initial feature/bug tickets to demonstrate proficiency in the tech stack and AI\-assisted development tools. **Within the first 90 days:** Hone development skills within the environment to contribute to the Receipts Management SOW in a meaningful way, delivering the first set of automated registry integrations. Establish a consistent high\-velocity coding loop using AI\-assisted tools (Cursor/Claude/Copilot), ensuring all contributions meet documented security and documentation standards. Actively participate in the Discovery process for North American registry integrations, helping to map technical debt and architectural requirements. **Within the first 6 months:** Contribute independently as a senior developer, co\-leading the technical execution of the North American registry integration phase. Help the team meet department goals by delivering production\-ready APIs and UI components that reduce manual processing time for the trading team. Demonstrate a firm grasp of the end\-to\-end SDLC by independently managing complex project slices from prototype to MVP. **Within 1 year:** Demonstrate success across all automation goals, achieving 90%\+ straight\-through processing for targeted registry transfers and retirements. Successfully decommission legacy components for the receipts process, migrating all core functionality to a stable, integrated enterprise platform. Serve as a mentor for the engineering team on AI\-first development best practices, driving continuous improvement in delivery speed and code reliability. **Our Benefits:*** Health and dental insurance; * Meal and food allowance; * Childcare assistance; * Extended parental leave; * Gym and health/wellness professional partnerships via Wellhub (Gympass) TotalPass; * Profit Sharing Plan (PLR); * Life insurance; * Continuous learning platform (CI\&T University); * Discount club; * Free online platform dedicated to promoting physical health, mental health, and well-being; * Pregnancy and responsible parenting course; * Partnerships with online course platforms; * Language learning platform; * And many others More details about our benefits here: https://ciandt.com/br/pt\-br/carreiras At CI\&T, inclusion begins at first contact. If you are a person with a disability, it is important to **submit your medical report during the selection process.** *Check which information must be included in the report* *by clicking here.* Thus, we can ensure the support and accommodations you deserve. **If you do not yet have the qualifying medical report, don’t worry: we can support you in obtaining it.** We have a dedicated Health and Well-being team, inclusion specialists, and affinity groups that will support you at every stage. Count on us to walk this journey alongside you.