• Mobile Application Development: Design and develop high-quality mobile applications for iOS and Android using .NET MAUI. • Architecture Implementation: Implement and maintain MVVM architecture for efficient data binding and separation of concerns. • API Integration: Integrate RESTful APIs to connect with backend services and manage data flow. • Platform-Specific Features: Implement features that leverage platform-specific capabilities to enhance user experience. • UI Development: Translate design specifications into functional mobile UI components using XAML and other relevant technologies. • Local Storage and Caching: Optimize data management through effective use of local storage and caching strategies. • Push Notifications: Integrate and manage push notifications for user engagement and timely updates. • Bug Fixing and Optimization: Identify and resolve performance bottlenecks, bugs, and other issues to enhance app stability and performance. • App Store Submission Support: Assist in the preparation and submission of applications to the App Store and Google Play Store.

• Design and implement scalable backend architecture • Build robust REST APIs for onboarding, contacts management, and outreach campaigns • Optimize database schemas and handle large datasets • Integrate Agentic AI workflows including automated outreach logic • Design and implement data pipelines for contact ingestion and analytics • Collaborate with frontend developers and AI/ML engineers • Write clean, testable code and support CI/CD pipelines

Role Description CharterUP is seeking a Senior Software Engineer – Backend to design, build, and operate the APIs and backend systems that power our mobile experience for a two-sided marketplace. This role will work closely with our Brazil-based mobile team, as well as U.S.-based engineering, product, and design partners, to deliver reliable, scalable services that enable high-quality user experiences. You’ll focus on backend service development, API design, and system reliability, helping ensure our mobile applications are fast, resilient, and able to scale with our growing business. What You’ll Do - Design, build, and operate scalable backend services and APIs for mobile applications, using modern and AI-assisted development practices. - Partner with mobile engineers to define API contracts and deliver seamless, high-performance user experiences. - Own service reliability, scalability, and performance, including deployment, monitoring, and optimization in AWS. - Drive backend best practices across testing, observability, and operational efficiency, leveraging AI-driven tooling where appropriate. - Collaborate cross-functionally to deliver high-impact features and identify opportunities to improve systems and workflows through AI. Qualifications - 4+ years of experience as a backend or full-stack engineer with a strong backend focus. - Proficiency in JVM-based languages (Java, Kotlin, etc.) and experience building scalable RESTful APIs. - Solid understanding of distributed systems, API design, and backend performance optimization. - Experience with cloud infrastructure (preferably AWS) and modern deployment practices, with exposure to AI-assisted tools for development, monitoring, or automation. - Strong ownership mindset and collaboration skills, with experience working closely with mobile or frontend teams in cross-functional environments. - Familiarity with the Backend-for-Frontend (BFF) pattern, including designing and maintaining mobile-optimized APIs that aggregate and tailor data for specific client use cases, improving performance and reducing client complexity. Requirements - Title: Senior Software Engineer - Backend - Reports to: Engineering Manager - Location: Brazil (Remote) Compensation - Estimated monthly rate: $6,000 – $7,000 USD Benefits - Remote-First Flexibility: Work from anywhere we hire, with built-in flexibility. U.S.-based employees may reside in any of our 19 approved states. - Comprehensive Health & Wellness: Medical, dental, and vision insurance, mental health support, virtual care, gym discounts, and family-building benefits. In the U.S., we cover 100% of premiums for employees. International benefits align with local standards. - Time Off to Recharge: Paid time off so you can truly unplug. U.S.: 15 PTO days (increasing to 20 after 2 years) + 8 paid holidays. International policies vary by country. - Financial Peace of Mind: Company-paid life, short-term, and long-term disability insurance where available. - Performance-Driven Culture: Join a fast-moving, ambitious, and collaborative team that wins together. - Referral Rewards: Earn bonuses for bringing top talent to the team. - Planning for the Future: Long-term financial planning support. U.S.: 401(k) plan. International: region-specific savings programs where applicable. - Top-Tier Tech: Choose a Mac or PC, plus monitor, keyboard, and mouse to hit the ground running. Recruiting Process - Step 1 - Video call: Talent Acquisition interview - Step 2 - Video call: Hiring Manager interview - Step 3 - Video call: Team interviews - Step 4 - Offer & reference check Company Description CharterUP is transforming the $450+ billion group transportation and mobility market with an AI native platform that powers modern charter, shuttle, and emerging autonomous vehicle operations. Trusted by many Fortune 500 companies, CharterUP connects enterprises, institutions, and event organizers to thousands of bus operators nationwide, while increasingly serving as the operating system for large scale shuttle and transit programs across airports, campuses, industrial sites, and major events.

• Work on the development, evolution, and maintenance of conversational text (WhatsApp) and voice (IVR) bots, focusing on generative AI solutions and building intelligent conversational flows using LLMs integrated with messaging platforms and APIs; • Interact directly with internal clients to understand requirements, propose technical solutions, and actively participate in squad refinement activities; • Design conversation flows — text and voice — with a focus on user experience and alignment with business requirements; • Integrate bots with APIs, legacy systems, and messaging platforms; • Use AI tools to accelerate development and improve code quality, actively contributing to an AI adoption culture within the squad; • Write and review automated tests, ensuring the quality and stability of deliveries; • Document technical solutions and developed flows, keeping knowledge accessible to the team; • Identify and propose technical and experience improvements for existing bots; • Collaborate with the QA team during validation and acceptance of deliveries; • Share technical knowledge with the team collaboratively, contributing to the squad's collective growth.