Senior Back End Engineer

**About Fold** Fold is a publicly traded Bitcoin financial services company offering the first-ever bitcoin-rewards Visa debit card, a bitcoin-rewards credit card, a Bitcoin exchange and wallet, and thousands of merchant offers. **About the Role** The Backend Engineering team maintains the fundamental systems powering Fold's products, including payment processing, ledger systems, card transaction flows, and the pipelines that tie it all together. As a senior engineer on this small team, you'll have considerable influence over product direction and technical strategy. **Responsibilities** * Design and implement scalable backend services for real-time transaction processing * Build and maintain event-driven systems that handle financial events * Integrate with external partners including card processors, banking APIs, and payment networks * Own features completely from technical design through deployment and ongoing monitoring * Work cross-functionally with product, design, and engineering colleagues to deliver iteratively * Mentor team members through code reviews, pair programming, and architectural discussions * Enhance engineering practices, tools, and infrastructure as the team scales **Required Qualifications** * 5+ years of professional software engineering experience with strong Java or similar statically-typed language proficiency (Kotlin, Scala, C#) * Production microservices and distributed systems experience * Familiarity with messaging or event streaming platforms (Kafka, Pulsar, or equivalent) * Solid relational database knowledge with data modeling and transactional consistency skills * Cloud infrastructure, CI/CD pipelines, and containerization competency * Experience scaling systems in fast-growing environments * Strong collaboration and communication abilities with a humble, team-oriented approach **Preferred Qualifications** * Financial systems, payment processing, or ledger/accounting domain expertise * Knowledge of event-driven architectures, CQRS, and event sourcing patterns * Experience with Micronaut, Quarkus, or comparable modern Java frameworks * Bitcoin enthusiasm * Active Fold product user **Benefits** * Fully remote team structure * Flexible scheduling and unlimited time off * Competitive salary with equity package * 401(k) with 3% employer match * Annual vacation stipend * Comprehensive health, vision, and dental coverage including HSA and FSA options * Paid parental leave * Quarterly in-person team gatherings * Bitcoin education resources and hardware wallet for new hires **Note:** Candidates must possess permanent legal work authorization in the United States. Visa sponsorship is unavailable for this position.