Java Backend Engineer

About the project

Our client is a fintech company building a new digital banking and payments product from scratch. The platform will cover card and payment processing, integrations with banks and payment providers, and core financial services for end customers.

The product is at an early stage: architecture, team and roadmap are being shaped now, and the scope will be refined together with the team. You will join a mixed team of client and NerdySoft engineers. AI-assisted development is part of everyday engineering.

What you will do

Design, build and ship backend services for a new event-driven platform

Build reliable integrations with banking and payment providers - idempotent, traceable and easy to reconcile

Write clean, well-tested code: unit, integration and contract tests

Take part in technical design and architecture discussions together with the Tech Lead

Review code and share knowledge within the team

Work with AI coding assistants and AI agents in daily development: delegate tasks to agents, review the code they produce and keep it to the team's standards for review and testing

Follow secure coding practices and security requirements, including PCI DSS

Support your features in production: monitoring, troubleshooting, fixes

Communicate directly with the client's engineers and stakeholders

What you bring

3+ years of commercial backend development with Java (17+) and Spring Boot

Production experience with asynchronous, event-driven systems (Kafka, RabbitMQ, AWS SNS/SQS or similar)

Good knowledge of concurrency and transactions: ACID, isolation levels, locking

Relational databases (PostgreSQL preferred), JPA / Hibernate, SQL query optimisation

REST API design and integration with external services: retries, timeouts, idempotency, error handling

Testing as part of the definition of done: JUnit, Mockito, Testcontainers

Docker, CI/CD and hands-on AWS (or another major cloud)

Daily use of AI coding assistants (Claude Code, Cursor, GitHub Copilot or similar): you can show how they speed you up and how you check their output

English B2+ (Upper-Intermediate or higher): you will communicate directly with the client's team

Nice to have

FinTech background: banking, payments or lending products

Card issuing or processing: ISO 8583, authorisation, clearing and settlement, reversals

Visa or Mastercard integrations

PCI DSS in practice; secure public APIs (authentication, authorization)

Ledger systems and double-entry accounting

DDD, Clean or Hexagonal architecture

Kotlin, Kubernetes, Terraform

What we offer

Comfortable workplace and modern office facilities

Flexible working hours with no overtime and the ability to work remotely

50% compensation for certifications, conferences, training

50% compensation for English courses

18 working days of paid annual leave

Paid sick leave

Medical insurance and sports compensation