Senior Full-Stack Engineer - Fintech & AI Product (LATAM) PT

Role Overview

Join our team as a Senior Full-Stack Engineer for the innovative fintech and AI product, CashCaptain. This role entails working within a modern TypeScript/Next.js environment to enhance our personal-finance web app, which helps users manage their financial lives. Your goal will be to fortify the existing codebase, improve data accuracy, refine core features, and develop new functionalities. This position is perfect for those who can quickly grasp an existing production setup and deliver polished product improvements.

Responsibilities

• Strengthen and clean up the existing production codebase by fixing bugs, enhancing reliability, and addressing technical debt.
• Enhance financial data accuracy, focusing on transfers, income, expenses, and cash-flow reporting.
• Refine transaction categorization logic to improve user-facing financial insights.
• Enhance recurring charge and subscription detection using advanced heuristics.
• Develop and refine core product features, such as budgeting and net-worth tracking.
• Lead new feature development from backend API to polished React UI.
• Deepen integration with Plaid, covering investments, liabilities, and transactions.
• Extend AI assistant capabilities, including chat and tool-calling using Anthropic Claude API.
• Write and maintain tests, including Playwright end-to-end tests.
• Deploy production updates using the existing CI/CD pipeline.

Required Skills

• Strong experience with TypeScript and React.
• Familiarity with modern React patterns, including hooks and component architecture.
• Experience with Next.js, particularly with App Router and React Server Components.
• Proficiency in SQL and data modeling, comfortable with raw SQL.
• Experience with API integration, particularly financial APIs like Plaid.
• Ability to quickly adapt to an existing production codebase.
• Strong debugging skills for data accuracy and business logic issues.
• Competence in safely refactoring code without introducing regressions.
• Capability to own features end-to-end and release to production.
• Clear written communication and sound judgment in balancing tasks.

Nice to Have

• Experience in fintech, personal finance, budgeting, or with Plaid.
• Background in building LLM or AI-powered product features.
• Familiarity with Anthropic or OpenAI SDKs.
• Knowledge in AI assistant workflows and tool calling.
• Experience migrating from SQLite to Postgres.
• Familiarity with Fly.io, Litestream, or similar deployment stacks.
• Experience with secure authentication, encryption, MFA, or rate-limiting systems.
• Strong product sense with an eye for clean, modern UI.