CashCow | Senior Full-Stack Developer (Next.js + FastAPI)

On behalf of CashCow, SD Solutions is looking for a talented Senior Full-Stack Developer to join our fast-growing team and work on high-impact products used by thousands of users daily. Are you passionate about building performant, modern web applications from frontend to backend?

SD Solutions is a staffing company operating globally. Contact us to get more details about the benefits we offer.

You will be responsible for architecting, developing, and maintaining both frontend and backend systems that power our core applications. This role is ideal for someone who has worked with modern web applications, backend APIs, and AI tooling within production pipelines. You will collaborate with product designers, PMs, and other engineers to deliver performant and scalable software.

Position is more back-end oriented (80% back-end, 20% front-end).

Responsibilities:

• Design, develop, and maintain user-facing applications with a strong focus on performance, usability, and maintainability
• Build and evolve backend services and APIs that support core product functionality
• Implement and maintain data-driven features, dashboards, and visualizations
• Integrate third-party services and AI-powered capabilities into the platform
• Ensure data integrity, validation, and secure handling across systems
• Write clean, testable, and well-documented code following engineering best practices
• Contribute to system architecture decisions and technical design discussions
• Identify performance bottlenecks and proactively optimize frontend and backend workflows
• Collaborate with cross-functional stakeholders to translate business requirements into technical solutions
• Participate in code reviews, technical planning, and continuous improvement initiatives

Requirements:

• 3+ years of professional experience building web applications
• Strong knowledge of React + Next.js and frontend tooling
• Proficiency in TypeScript and modern CSS with TailwindCSS
• Experience with state management and data fetching libraries (Zustand, TanStack Query)
• Backend development experience with Python & FastAPI
• Working knowledge of SQLAlchemy and database design
• Hands-on with testing frameworks (pytest) and linting (ESLint, Ruff)
• Experience working with AI-powered systems or tools in production environments
  
• Prior experience integrating and working with SDKs as part of an existing technical pipeline
  
• Practical understanding of AI/ML workflows, including model integration and inference
  
• Hands-on exposure to PyTorch or similar machine learning frameworks
  
• Familiarity with building, maintaining, or extending AI pipelines within backend systems
  
• Ability to architect scalable systems and write clean, maintainable code
• Excellent written and verbal communication skills
• Comfortable working in a fast-paced, autonomous environment
  

Advantages:

• Experience with OpenAI ChatKit / Agent SDK or other AI frameworks
• Experience working with LLM-based tools, agents, or AI orchestration pipelines
  
• Background in developing or supporting machine learning–enabled features
  
• Experience collaborating with data science or ML teams
  
• Understanding of AI model lifecycle considerations (experimentation, deployment, iteration)
  
• Familiarity with monitoring and deployment platforms
• Contributions to open-source or personal tech projects
  

About the company:

CashCow is a fast-growing fintech company that is on a mission to revolutionize financial services through innovative technology. The team is building cutting-edge solutions to enhance user experience, streamline payments, and drive financial automation.

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