Software Engineer

B3 Consulting Poland; United States; Remote; USD 46,000 - 72,000; Full time

Benefits offered by this job

Health benefits

Speed Coaching

Sports training

Team events

Job summary

B3 Consulting Poland is seeking an Senior Software Engineer to design and scale backend microservices for the merchant payments domain. You will build core services for prepaid wallets, payment gateway integrations, invoicing, and reporting.

Work in an environment that values architectural discipline and scalable deployment. You will migrate legacy services to Clean and Hexagonal architectures, implement event-driven integrations with Kafka, and own full lifecycle deployment using Helm, GitLab

Qualifications

• Experience with backend microservices using Java or Kotlin, Spring Boot, Clean Architecture, and Hexagonal Architecture.
• Experience with event-driven architecture using Kafka and Avro, alongside REST integrations.
• Knowledge of financial logic handling, including idempotent endpoints, precise monetary calculations, and PII protection.
• Experience with testing and quality tools using Spock, Testcontainers
• Experience with GitOps and DevOps practices using Helm, GitLab CI, and Kubernetes.

Responsibilities

• Design and deliver backend microservices in the merchant payments and reporting domain, including prepaid wallets, invoicing, and SAP / payment gateway integrations.
• Migrate legacy services to Clean Architecture and Hexagonal Architecture, keeping domain logic framework-free and documenting choices via Architecture Decision Records.
• Build event-driven integrations over REST and Kafka with Avro, enforcing idempotency and money handling correctness.
• Own full lifecycle deployment and quality using Helm, GitLab CI, GitOps on Kubernetes, and testing with Spock, Testcontainers, and Spring Cloud Contract.

Skills

Java

Kotlin

Spring Boot

Clean Architecture

Hexagonal Architecture

Kafka

Avro

REST

Event-driven

Testing (Spock, Testcontainers)

Kubernetes

Helm

GitLab CI

GitOps

Tools

Spock

Testcontainers

Kubernetes

Helm

GitLab CI

GitOps

Kafka

Avro

Job description

Описание:

We are part of an international organization listed on Nasdaq Stockholm, operating in 11 countries. In Poland, we work with full autonomy. We independently choose our technologies, processes, and ways of working while maintaining the highest professional standards. We deliver a wide range of IT projects in Poland and internationally, across multiple domains and technologies. This allows our consultants to develop their competencies and gain experience aligned with their professional ambitions. Our collaboration is built around the CARE philosophy. For us, it means responsible project matching, transparent cooperation, and a long-term approach to professional growth. Join us as Senior Software Engineer. In this role, you will design and scale backend microservices for the merchant payments domain, building core services for prepaid wallets, payment gateway integrations, invoicing, and reporting. Grow in an environment that cares about your development as much as you do.

Задачи:

Design and deliver backend microservices in the merchant payments and reporting domain, including prepaid wallets, invoicing, and SAP / payment gateway integrations. Migrate legacy services to Clean Architecture and Hexagonal Architecture, keeping domain logic framework-free and documenting choices via Architecture Decision Records. Build event-driven integrations over REST and Kafka with Avro, enforcing idempotency and money handling correctness. Own full lifecycle deployment and quality using Helm, GitLab CI, GitOps on Kubernetes, and testing with Spock, Testcontainers, and Spring Cloud Contract.

Требования:

Experience with backend microservices using Java or Kotlin, Spring Boot, Clean Architecture, and Hexagonal Architecture. Experience with event-driven architecture using Kafka and Avro, alongside REST integrations. Knowledge of financial logic handling, including idempotent endpoints, precise monetary calculations, and PII protection. Experience with testing and quality tools using Spock, Testcontainers Experience with GitOps and DevOps practices using Helm, GitLab CI, and Kubernetes. Experience using AI-assisted and agentic coding tools (such as Claude Code, GitHub Copilot, Cursor, or Codex) You need to live in Poland and/or be eligible to work here.

Условия:

Work in a Scandinavian culture built on logic and dialogue.

• Health and sports benefits tailored to your needs.
• Speed Coaching – short sessions that provide new perspectives and solutions.
• Sports training, an internal team, and opportunities to take part in competitions.
• Team events and development-focused meetups.