Senior Kotlin Backend Developers
Summary
6-month extendable contract via Kozak Agency to help build a greenfield Accounting Engine for a client. Senior Kotlin developers work remotely (within ±1h of Germany) on Spring Boot/WebFlux services on AWS with PostgreSQL/Aurora, using event sourcing, DDD and strict TDD/quality practices.
Project Details
Project: Greenfield Accounting Engine
Start: Mid/late October, latest early November 2026
Duration: 6 months with option for extension
Workload: 120–160 hours/month
Location: Remote / Nearshore
Time Zone: Maximum ±1 hour from Germany
Language: English
Team: 5 Backend Developers + 1 Engineering Manager
The project is particularly suitable for experienced backend engineers who are comfortable working in a modern, architecture-driven environment with a strong focus on engineering quality, scalability and structured software delivery.
Developer focus: Kotlin + Spring Boot/WebFlux + AWS + Event Sourcing + DDD + TDD, with very strong software quality standards.
The client is building a new Accounting Engine that will become the central accounting platform for new markets. The solution will process business events such as invoices, receipts and transactions, generate accounting entries, and support reporting and further data-driven analytics.
Must-have
Backend:
Kotlin
Spring Boot
Spring Boot WebFlux
AWS
PostgreSQL
AWS Aurora PostgreSQL
Architecture:
Event Sourcing
Domain-Driven Design (DDD)
Modern backend architecture
Желательно Hexagonal Architecture
Quality:
TDD
Test-driven development
High test coverage
Strong software quality standards
Quality gates
🟡 Should-have
jOOQ
Flyway
Hexagonal Architecture
Greenfield projects
GitHub
GitHub-based CI/CD
SonarCloud
Experience working with Product Owners
Delivery-driven development
🟢 Nice-to-have
AI Engineering
AI-assisted development
AI Delegated Engineering
Claude / Cursor
Basic accounting knowledge