Senior Back End Engineer (Java/Kotlin)

Company: Fold

About the Company: Fold is a publicly listed Bitcoin financial services company (listed February 2025). They've built the first Bitcoin-rewards Visa debit card, a Bitcoin-rewards credit card, a Bitcoin exchange and wallet, and thousands of merchant offers. Growing fast with a passionate, loyal community featured in Fortune and Bloomberg. Small team solving hard problems in financial infrastructure.

Job Category: Software Engineering / Backend / Fintech / Bitcoin

Contract Type: Full-Time, Permanent Location: Remote — USA only (regulatory requirement)

Salary: Competitive + equity + 401K with 3% match + benefits (apply for exact figure)

Application Link: https://fold.app/careers (posted on HN Who's Hiring May 2026) Posted: May 1, 2026

Job Description: You'll design, build, and scale backend services that power Fold's payment processing, ledger systems, card transaction flows, and event-driven pipelines. Small team, big impact — every engineer has direct visibility into how their work shapes the product.

Key Responsibilities:

• Design, build, and scale backend services powering payments, ledger systems, and card transaction flows
• Build and maintain event-driven pipelines connecting Fold's financial infrastructure
• Collaborate with a small, tight-knit engineering team to make technical decisions with real product impact
• Ensure system reliability and performance for financial-grade infrastructure

Requirements:

• 5+ years of software engineering experience
• Strong Java or similar language skills (Kotlin, Scala, C# all considered)
• Production microservices and distributed systems experience
• Familiarity with messaging and event streaming platforms (Kafka, Pulsar)
• Solid relational database and data modeling skills

Nice to have: Fintech, payments, or ledger/accounting domain experience; event-driven architectures, CQRS, event sourcing; Micronaut, Quarkus, or similar modern Java frameworks; interest in Bitcoin.

Benefits: Competitive salary, equity, 401K with 3% match, unlimited PTO, yearly vacation stipend (they pay you to go on vacation and not work), annual company retreats, no Monday meetings on the 1st and 3rd Monday of each month, "Spin and Go Weekend Wheel" — they'll randomly pay you to travel for a weekend. Bitcoin starter pack for new hires with hardware wallet.