Senior Full Stack Engineer

Senior Full Stack Engineer (Python, FastAPI & AI-Assisted Development) - Remote

Position Type: Full-Time, Remote

Working Hours: U.S. Client Business Hours (with flexibility 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, build, and scale a modern tax filing platform from the ground up.

This isn’t just another software engineering role.

You’ll own the architecture, backend services, frontend experience, and key technical decisions behind a mission-critical platform where security, accuracy, reliability, and scalability are essential.

You’ll work extensively with AI-assisted development tools such as Cursor and Claude Code to accelerate development while maintaining exceptional engineering standards and code quality.

If you enjoy solving complex technical challenges, building scalable systems, and taking ownership from architecture through deployment, this role is built for you.

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 intuitive, responsive frontend interfaces for complex workflows.
• Design scalable REST APIs and service architectures.
• Integrate frontend and backend systems seamlessly.

System Architecture & Technical Design

• Own end-to-end application architecture.
• Design scalable data models and service boundaries.
• Build systems optimized for long-term maintainability.
• Drive technical decisions that improve scalability, reliability, and performance.
• Identify architectural risks and recommend practical solutions.

Backend Development

• Develop secure REST APIs using FastAPI.
• Build business logic for workflow-driven applications.
• Integrate third-party APIs and external services.
• Optimize API performance and application responsiveness.
• Develop reliable background jobs and asynchronous processing workflows.

Frontend Development

• Build user-friendly interfaces for:
• Forms
• Dashboards
• Workflow management
• Develop responsive, reusable UI components using modern JavaScript frameworks.
• Integrate frontend applications with backend APIs.
• Improve usability while maintaining accessibility and performance.

AI-Assisted Software Development

• Utilize Cursor and Claude Code throughout the software development lifecycle.
• Build AI-assisted workflows that improve engineering productivity.
• Use AI to accelerate:
• Development
• Debugging
• Testing
• Documentation
• Continuously improve engineering workflows using emerging AI tools.

Testing, Quality & Reliability

• Develop and maintain:
• Unit tests
• Integration tests
• End-to-end tests
• Maintain high code quality standards.
• Improve system stability and reliability.
• Refactor code to reduce technical debt and improve maintainability.

Security & Data Integrity

• Implement robust validation and error handling.
• Ensure secure handling of sensitive user information.
• Follow best practices for:
• Authentication
• Authorization
• Input validation
• Build systems where data integrity and accuracy are critical.

Documentation & Collaboration

• Document architecture decisions and technical implementations.
• Collaborate with Product Managers, Engineers, and stakeholders across time zones.
• Participate in:
• Sprint planning
• Technical discussions
• Code reviews
• Communicate risks, blockers, and recommendations proactively.

What Makes You a Strong Fit

• Ownership mentality with a passion for building high-quality software.
• Strong problem-solving skills and ability to work independently.
• Comfortable making architectural decisions.
• Excellent communication and collaboration skills.
• Passion for continuous learning and AI-assisted engineering.
• Strong focus on scalability, maintainability, and clean code.

Required Experience & Skills

Experience

• 5+ years of professional Full Stack Software Engineering experience.
• Proven experience designing and delivering production-grade web applications.

Backend Skills

• Strong expertise in:
• Python
• FastAPI
• REST API development
• Experience building workflow-driven or form-heavy applications.
• Experience with:
• PostgreSQL or similar relational databases
• API integrations
• Git

Frontend Skills

• Strong experience with modern JavaScript frameworks.
• Experience building responsive web applications and complex user interfaces.

AI & Development Tools

• Hands-on experience using:
• Cursor
• Claude Code
• AI-assisted software development tools

Communication

• Excellent written and verbal English communication skills.

Nice-to-Have

• Experience in:
• FinTech
• Tax software
• Compliance platforms
• Financial systems
• Experience building highly secure applications.
• Familiarity with distributed engineering teams and asynchronous collaboration.
• Experience designing scalable cloud-based architectures.

What a Typical Day Looks Like

• Review sprint priorities and overnight updates.
• Build backend APIs and frontend features.
• Design scalable application architecture.
• Implement workflow logic and business rules.
• Use Cursor and Claude Code to accelerate development.
• Collaborate with Product and Engineering teams.
• Write automated tests and review pull requests.
• Document technical decisions and deployment updates.

In short: You’ll architect, build, and continuously improve a mission-critical software platform while owning technical execution from architecture through production.

Key Metrics for Success (KPIs)

• High-quality features delivered on schedule.
• Secure, reliable, and scalable application performance.
• Low production defect rates.
• Strong automated test coverage.
• Well-documented, maintainable code.
• Positive collaboration across engineering and product teams.

Why Join Us?

• Architect and build a mission-critical platform from the ground up.
• High ownership with meaningful technical impact.
• Work with modern AI-assisted software development tools.
• Solve complex engineering challenges at scale.
• Fully remote work environment with flexible collaboration.
• Growth opportunities into:
• Staff Engineer
• Technical Lead
• Engineering Manager
• Software Architect

Interview Process

• 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 full stack engineering background, highlight your experience with Python, FastAPI, frontend development, system architecture, and AI-assisted development tools such as Cursor or Claude Code, and share examples of complex systems you’ve built or scaled. 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 from architecture through deployment, we’d love to hear from you. Apply today and help build the next generation of secure, high-impact software solutions.