Full Stack Engineer

Who you are

• 4-6 years of professional software engineering experience in full-stack web development
• Strong proficiency in Java (11+) and Spring Boot, including Spring Security, Spring Data JPA, and RESTful API design
• Strong proficiency in React (16+) with TypeScript, including hooks, state management, and modern component patterns
• Solid experience with PostgreSQL including schema design, query optimization, indexing strategies, and migrations
• Experience with CSS frameworks (Tailwind CSS preferred) and building responsive layouts
• Familiarity with cloud services, particularly AWS (S3, SES, Lambda, ECS, CloudWatch)
• Experience integrating with third-party REST APIs and OAuth 2.0 authentication flows
• Understanding of Git workflows, pull request processes, and collaborative development practices
• Ability to independently own features from technical design through deployment
• Strong debugging skills across frontend and backend, including browser DevTools and server-side logging
• Must be able to work primarily between the hours of 9:30 AM - 6:30 PM ET
• Must have a player/coach mentality, willing to both execute and lead
• Ability to juggle multiple projects concurrently and set and meet deadlines
• Skilled at receiving and providing direct feedback
• Collaborative mindset and great teamwork skills
• Entrepreneurial & adaptable; great learning skills
• Curious, research-minded, data-informed
• Able to search for possible solutions and apply them
• Creative confidence
• Proactive communicator
• A sense of humor and a love of online culture
• Thrives in a start-up culture

What the job involves

• Join the COOL company as a Mid-Senior Full-Stack Engineer to build end-to-end ad tech with React/TypeScript and Java/Spring Boot, shaping AI-powered advertising for global brands
• We are looking for a Mid-Senior Full-Stack Engineer to join our Product Engineering team, reporting to the Engineering Manager (Bi Yoo)
• This role is responsible for building and maintaining the web applications that power our advertising platform, including the Cool AI campaign management system, billing and invoicing module, and advertiser-facing dashboards
• The Full-Stack Engineer will work across our frontend (React/TypeScript) and backend (Java/Spring Boot) stack, delivering features end-to-end from database schema design through API development to polished UI implementation
• This role spans the full product surface of a growing ad tech platform
• You'll build features that advertisers interact with daily — campaign creation and launch workflows, real-time performance dashboards, multi-platform account
• Integrations (Google Ads, Meta, Adform), and automated billing systems
• There is significant opportunity to shape product architecture as we scale to support new advertising channels, expand our AI-driven campaign optimization, and onboard enterprise clients with complex billing and permissions requirements
• Design and implement full-stack features across React (TypeScript, Tailwind CSS, Vite) and Spring Boot (Java 17, PostgreSQL) codebases
• Build and maintain RESTful APIs with proper authentication, authorization (role-based access control), and input validation
• Design and evolve PostgreSQL database schemas using Flyway migrations, including JSONB modeling for flexible domain objects
• Develop responsive, accessible UI components following existing design patterns and component libraries
• Integrate with third-party advertising platform APIs (Google Ads, Meta Marketing API, Adform) for account management and data synchronization
• Implement and maintain OAuth flows for external platform connections
• Build complex business logic including billing calculations, invoice generation, and payment processing workflows
• Write efficient database queries and optimize application performance for large datasets
• Collaborate with the data engineering team on Snowflake integrations for analytics and reporting features
• Participate in code reviews, providing constructive feedback and maintaining code quality standards
• Troubleshoot production issues across the full stack using AWS CloudWatch logs and application monitoring
• Contribute to CI/CD pipeline maintenance and deployment processes

The application process

• We usually respond within two weeks

Benefits

• Health, Dental and Vision Insurance
• Annual Performance Bonus
• Paid Time Off
• Company Holidays
• Flexible work schedule
• 401k