Full Stack Software Engineer (contract)

As a Full Stack Software Engineer at CoinFlip, you'll work across backend services and frontend applications that support customer onboarding, transaction management, compliance workflows, and internal operational tools. You'll collaborate closely with product managers, designers, engineers, and operations teams to deliver reliable, end-to-end solutions backed by scalable backend systems and intuitive user experiences.

What you'll do

• Design, build, and maintain full-stack features across frontend applications and backend services
• Develop and maintain backend APIs that support onboarding, authentication, transaction lifecycles, and operational workflows
• Build and enhance front-end experiences in customer-facing and internal web applications
• Integrate systems with third-party services and external providers
• Implement secure authentication and authorization using OAuth 2.0 flows
• Work within a microservices environment to deliver scalable backend capabilities
• Ensure applications meet high standards for security, performance, reliability, and observability, including monitoring
• Participate in code reviews, technical design discussions, and architecture decisions
• Write and maintain clear technical documentation

What you bring

• 3+ years of experience as a software engineer working across frontend and backend systems
• Strong experience building backend services in Golang and/or Java
• Proficiency with Node.js and TypeScript v5
• Experience building frontend applications using Next.js, React, and TypeScript
• Solid understanding of RESTful API design
• Strong SQL skills and experience with PostgreSQL
• Experience working in an AWS environment
• Familiarity with microservices and distributed backend systems
• Experience with monitoring and observability platforms such as Grafana
• Experience with Kubernetes
• Experience with Terraform and Helm
• Clear communication skills and a collaborative, ownership-oriented mindset

Nice to have

• Understanding of multi-threading and goroutines
• Experience integrating third-party APIs and external providers
• Webhooks experience
• WebSocket experience
• Architecture and design experience
• Comfort using AI tools
• Experience in fintech, crypto, payments, or other regulated industries
• Experience building internal dashboards or operational tooling
• Familiarity with authentication, authorization, and secure system design
• Comfort owning features end-to-end across the stack

What we offer

• Annual base salary of $45,000-$55,000, subject to experience
• Performance-based incentives
• Competitive benefits for full-time employees
• Collaborative and positive working environment

About CoinFlip

CoinFlip is a global digital currency platform company operating the world's largest network of cryptocurrency kiosks by transaction volume, with more than 5,500 kiosks across 49 U.S. states and 10 countries. Founded in 2015 and headquartered in Chicago, CoinFlip has been recognized on the Inc. 5000 list for 2021-2023 and the Deloitte Technology Fast 500 for 2022-2023, and has won multiple awards for customer service and workplace culture.