Senior Kotlin Engineer; Fintech Projects

Senior

Full time

We’re looking for a Senior Kotlin Backend Engineer to join an outsourced team working on a financial platform for business accounting and financial management. The product is already in production, so the focus is on extending and improving it, not building from scratch. The upcoming scope covers banking integrations, transaction processing, reconciliation, cash-flow forecasting, accounting automation, and analytics.

You’ll work closely with the client’s technical team, who will provide knowledge transfer on the existing architecture. We’re looking for engineers who can quickly get up to speed in an established codebase and take ownership of reliable backend delivery in a complex financial domain.

The platform covers bank account management, transaction and balance imports, cash-flow forecasting, recurring commitments, payment workflows, accounting sync, and reconciliation. It is built on event-driven processing and workflow orchestration. Key technical areas are Kotlin backend services, APIs, async event processing, databases, and integrations with banking and accounting systems.

2 Senior Kotlin Backend Engineers, 1 Backend Engineer, 1 Frontend Engineer, 1 QA, 1 BA, 1 PM.

• 5+ years of backend development, with substantial production experience in Kotlin and the JVM ecosystem
• Strong experience with REST APIs and maintainable service design
• Strong SQL, data modeling, and database performance skills
• Hands-on experience with messaging or event-driven architectures
• Understanding of distributed-systems challenges: idempotency, retries, duplicate messages, concurrency, eventual consistency
• Experience with automated testing, Git, code reviews, and CI/CD
• Understanding of authentication, authorization, and secure handling of sensitive data
• Ability to work independently in an existing, non-trivial codebase
• Experience in Fin Tech, banking, accounting, or payment systems
• English B2/C1

• PostgreSQL and transaction management
• AWS SQS/SNS or similar messaging
• Temporal or other workflow orchestration tools
• Multi-tenant applications and tenant-level access control
• Third-party API integrations, webhooks, and signature verification
• OpenAPI with generated clients
• Docker, Kubernetes, Helm

Odoo or other ERP/accounting systems. Type Script, Node.js/NestJS, Prisma. AWS infrastructure, secrets management, and monitoring. Data warehouses, SQLMesh, or analytical models. Domain experience in forecasting, AP/AR, reconciliation, or accounting automation. Taking over a product from another team.

• Backend development: extend the Kotlin Backend-for-Frontend (BFF) layer with APIs and business logic for new financial features
• Design REST APIs contract-first using OpenAPI
• Integrate new functionality into the existing architecture without breaking current behavior
• Support integration between Kotlin services, Type Script/NestJS services, and external systems
• Build and extend integrations with banking providers (account connections, transaction imports, balance sync) and accounting systems, including Odoo
• Develop transaction-processing and reconciliation workflows that handle partial payments, duplicates, retries, and concurrency
• Implement event-driven communication (event contracts, consumers, transactional outbox) and scheduled or async workflows
• Ensure data consistency across APIs, services, and analytics
• Implement tenant-aware authorization and access control
• Apply idempotency, safe retries, version checks, and proper transaction boundaries
• Improve observability through logging, metrics, health checks, and alerts
• In…