Senior Full Stack Engineer

Senior Full Stack Engineer (Python, FastAPI & AI-Assisted Development) – Remote Job Type: Full-Time, Remote Working Hours: U.S. Client Business Hours (flexibility required for sprint reviews, deployments, and production support) About the Role At Pavago, one of our clients is hiring a Senior Full Stack Engineer to architect and build a modern tax filing platform from the ground up. This is more than a software engineering role. You’ll own the architecture, backend services, frontend experience, and technical direction of a mission-critical platform where security, accuracy, and reliability are essential. You’ll leverage AI-assisted development tools such as Cursor and Claude Code to accelerate delivery while maintaining exceptional code quality and engineering standards. If you’re passionate about building scalable applications, solving complex technical challenges, and taking ownership from architecture through production, this role is a strong fit. What You’ll Own Full-Stack Application Development Design, build, and maintain production-grade web applications. Develop secure backend services using Python and FastAPI. Build responsive, intuitive frontend interfaces for complex workflows. Design scalable REST APIs and service architectures. Integrate frontend and backend systems seamlessly. System Architecture & Technical Leadership Own end-to-end application architecture. Design scalable data models and service boundaries. Drive technical decisions that improve scalability, maintainability, and reliability. Identify technical risks and recommend practical solutions. Build systems designed for long-term growth and performance. Backend Development Develop secure REST APIs using FastAPI. Build business logic for workflow-driven applications. Implement third-party integrations and external services. Optimize API performance and backend scalability. Develop reliable background processing and asynchronous workflows. Frontend Development Build responsive interfaces for dashboards, forms, and workflow management. Develop reusable UI components using modern JavaScript frameworks. Integrate frontend applications with backend APIs. Improve usability while maintaining performance and accessibility. AI-Assisted Engineering Leverage Cursor and Claude Code throughout the development lifecycle. Build AI-assisted workflows that improve engineering productivity. Use AI to accelerate coding, debugging, testing, and documentation. Continuously improve development workflows using emerging AI technologies. Testing, Quality & Reliability Write and maintain: Unit tests Integration tests End-to-end tests Maintain high code quality standards. Reduce technical debt through continuous refactoring. Improve application stability and production reliability. Security & Data Integrity Implement robust validation and error handling. Ensure secure handling of sensitive financial information. Follow best practices for authentication, authorization, and input validation. Build highly secure, reliable, and compliant applications. Documentation & Collaboration Document architecture decisions and technical implementations. Collaborate with product, engineering, and stakeholders across distributed teams. Participate in sprint planning, code reviews, and technical discussions. Communicate risks, blockers, and recommendations proactively. What Success Looks Like High-quality features delivered on schedule. Secure, reliable, and scalable application performance. Strong automated test coverage. Clean, maintainable, and well-documented code. Low production error rates and reduced technical debt. Effective collaboration across engineering and product teams. What Makes You a Strong Fit You think like an owner, not just a contributor. You proactively solve problems without waiting for detailed specifications. You thrive in complex, detail-oriented environments. You communicate clearly and collaborate effectively. You embrace continuous learning and feedback. You care deeply about code quality, scalability, and maintainability. Required Experience & Skills Experience 5+ years of professional Full Stack Software Engineering experience. Strong expertise with: Python FastAPI REST API development Experience designing, building, and shipping production applications. Strong frontend development experience with modern JavaScript frameworks. Experience building workflow-driven or form-heavy applications. Hands-on experience using: Cursor Claude Code AI-assisted development tools Experience with: PostgreSQL or similar relational databases Git API integrations Excellent written and verbal English communication skills. Nice to Have Experience in: FinTech Tax software Compliance platforms Financial systems Experience building highly secure applications. Experience designing scalable software architecture. Familiarity with asynchronous collaboration in distributed engineering teams. Tech Stack Python FastAPI PostgreSQL REST APIs Modern JavaScript Frameworks Git Cursor Claude Code AI-Assisted Development Tools What a Typical Day Looks Like Review sprint priorities and engineering updates. Design and develop backend APIs and frontend features. Improve application architecture and system scalability. Build workflow logic and business-critical functionality. Use AI tools to accelerate development and testing. Collaborate with product managers and engineers. Review pull requests and maintain code quality. Document technical decisions and implementation updates. In short: You’ll architect, build, and continuously improve a secure, scalable software platform while owning technical execution from system design through production deployment. Key Metrics for Success (KPIs) Feature delivery quality and timeliness. Application reliability and scalability. Automated test coverage. Production stability and low defect rates. Code quality and maintainability. Technical documentation quality. Cross-functional collaboration and engineering impact. Why This Role Stands Out Build a mission-critical platform from the ground up. High ownership over architecture and technical decisions. Work with modern AI-assisted engineering workflows. Solve challenging problems in a high-impact environment. Fully remote role with flexible collaboration. Career growth into: Staff Engineer Technical Lead Engineering Manager Software Architect Interview Process Application Review Spark Hire Intro Video (3–5 minutes) Technical Assessment Client Interview Offer & Onboarding What Happens After You Apply After submitting your application, you’ll receive an email invitation from Spark Hire to record a short 3–5 minute Intro Video . This is the first step in our hiring process and can be completed whenever it’s convenient for you. Instead of multiple initial screening calls, you’ll have one opportunity to introduce yourself, discuss your experience building production-grade applications with Python and FastAPI, designing scalable system architectures, developing modern frontend applications, and using AI-assisted development tools such as Cursor or Claude Code. You’ll also have the opportunity to highlight projects where you’ve taken ownership from architecture through deployment. Your video will be reviewed by the hiring team before moving to the technical assessment and client interview. You can record your video as many times as you’d like before submitting it—only your final version will be reviewed. Please keep an eye on both your inbox and spam folder for your Spark Hire invitation after applying. Apply Now If you’re passionate about building scalable software, leveraging AI to improve engineering workflows, and taking ownership of complex technical challenges, we’d love to hear from you. Apply today and help build a next-generation platform from the ground up.