Full Stack Software Engineer (contract)

CoinFlip is a global digital currency platform company, focused on providing consumers simple and secure access to buy and sell cryptocurrency. The company operates the world's largest network of cryptocurrency kiosks by transaction volume with more than 5,500 kiosks across 49 U.S. states, Puerto Rico, Canada, Australia, New Zealand, South Africa, Italy, Panama, Brazil Mexico, and Spain. CoinFlip’s digital currency kiosks make buying and selling major cryptocurrencies accessible and safe for consumers who wish to purchase their digital currency using cash. CoinFlip also operates CoinFlip Preferred, a personalized over-the-counter service that provides investors with custom, white glove support for their cryptocurrency transactions. In 2022, CoinFlip launched CoinFlip Ventures, an investment group offering coaching, funding, and networking support to early-stage crypto and web3 projects.

CoinFlip was founded in 2015 by Daniel Polotsky, Kris Dayrit, Alan Gurevich, and Ben Weiss. Headquartered in Chicago, CoinFlip placed in the top 500 on the 2021, 2022, and 2023 Inc. 5000 list, and on the 2022 and 2023 Deloitte Technology Fast 500, was named the 2021 and 2022 #1 fastest-growing company in Chicago by Crain's, ranked in Chicago Tribune’s Top Workplaces in 2021 and 2022, and was awarded the 2021 and 2022 Stevie ® Awards for Customer Service. To learn more about CoinFlip and how to get started on your digital currency journey, visit www.CoinFlip.tech.

We’re looking for a Full-Stack Software Engineer to join our engineering team. This role will work across both backend services and frontend applications that support customer onboarding, transaction management, compliance workflows, and internal operational tools across CoinFlip’s product ecosystem. 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.

Responsibilities:

• 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.

Tech Stack

• This role will work within CoinFlip’s existing application and infrastructure stack, including:
• Backend: Golang, Java
• Frontend: Next.js, React, TypeScript (including TypeScript v5), Node.js (primary for Wallet)
• APIs: RESTful APIs
• Databases: SQL, PostgreSQL
• Infrastructure & Cloud: AWS (including S3), containerized services; Kubernetes; Helm and Terraform
• Authentication & Identity: OAuth 2.0 flows
• Monitoring/Observability: Monitoring platforms (e.g., Grafana)
• Version Control & CI/CD: Git-based workflows with CI/CD pipelines
• Developer Workflow: Experience with VS Code / Cursor debugging workflows

Requirements

• 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 / TypeScript v5 (primary for Wallet).
• 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/observability platforms (Grafana, etc.).
• Experience with Kubernetes.
• Experience with Terraform / Helm.
• Clear communication skills and a collaborative, ownership-oriented mindset.

Nice to Have

• Understanding multi-threading and goroutines.
• Experience integrating third-party APIs and external providers.
• Webhooks experience.
• WebSocket experience.
• Architecture/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.

Compensation

• Annual base salary, range subject to experience: $45,000 - $55,000

Working at CoinFlip means collaborating with experienced and innovative leaders who share a clear vision and a track record of success. We offer a collaborative and positive working environment where we encourage employees to balance productivity with time to recharge. Compensation is above and beyond a typical “startup” — we offer competitive salaries, performance-based incentives, and competitive benefits for full-time employees.

CoinFlip values diversity in the workplace and is an equal opportunity employer committed to providing an inclusive and accessible work environment. We thank all candidates who apply, but only those selected for an interview will be contacted.

By applying to this role, you give express consent to CoinFlip to send you informational text (SMS) messages regarding this role and the application process. You can cancel the SMS service at any time by replying "STOP" to the text message you received. If at any time you forget what keywords are supported, just reply "HELP." Message and data rates apply. If you require a special accommodation, please let us know and we’ll work with you to meet your needs.