Senior Backend Engineer (Node.js / Kotlin)
About This Role
The backend consists of microservices supporting wallet synchronization, push notifications, referral and promotional programs, crypto payments, DeFi and staking integrations, and analytics pipelines. The tech stack includes TypeScript, Node.js, NestJS, and TypeORM for current services; Kotlin and Spring for new services; AWS and Kubernetes for infrastructure; PostgreSQL and Redis for data storage; SQS and BullMQ for messaging; and React for admin tools.
What You'll Be Doing
Design, build, and maintain scalable backend services across the Node.js and Kotlin stacks
Write clean, well-tested code, treating testing as a first-class concern
Own features end-to-end, including decomposing tasks and making technical decisions
Maintain and evolve existing NestJS services while building new services in Kotlin/Spring
Occasionally build internal tools and admin interfaces using React
Collaborate with product, DevOps, and engineering teams on cross-functional delivery
Participate in code reviews, architecture discussions, and ongoing improvements to system reliability and observability
What We're Looking For
Strong production experience with Kotlin or Java, and Spring
Comfort working with Node.js and NestJS for maintaining existing services
Strong testing practices
Deep understanding of software architecture, design patterns, and microservices
Experience with AWS services such as Lambda, SQS, and S3
Experience with containerized environments and Kubernetes
Good communication and collaboration skills
Bonus Points
Experience in fintech, crypto, or payment systems
Ready to Apply?
To submit your application for this position, please visit Tangem AG's official website and follow their application process.