Senior Go Engineer (Core Banking)

Colibrix One; Kraków; On-site; PLN 240,000 - 320,000; Full time

Benefits offered by this job

Competitive salary

Flexible work arrangements

Learning opportunities

Job summary

COLIBRIX ONE is seeking an experienced Go Engineer to join our team and contribute significantly to our payment gateway product. The ideal candidate will bring deep technical expertise, a collaborative mindset, and the ability to mentor teammates through knowledge and experience rather than formal authority.

You will work on distributed, transaction-critical fintech systems with a strong focus on reliability, security, and scalable microservices, shaping the future of digital payments.

Qualifications

• 5+ years of professional Go development experience, including fintech/payments or transaction-critical systems.
• Strong knowledge of distributed systems, microservices, and API design (REST and gRPC).
• Advanced PostgreSQL skills, including transactions, isolation levels, indexing, migrations, and concurrency.
• Experience designing reliable transactional systems using idempotency, retries, event deduplication, transactional outbox, sagas, and reconciliation.
• Hands-on experience with event-driven architectures and message brokers like NATS, Kafka, or RabbitMQ.
• Experience building and operating production services, including incident investigation, safe deployments, database migrations, and observability.
• Practical knowledge of AWS, Kubernetes, and CI/CD.
• Experience integrating with banks, payment providers, AML/KYC, or anti-fraud platforms.
• Understanding of security requirements for financial data and translating business requirements into technical solutions.

Skills

Go development

Fintech/payments experience

Distributed systems

API design REST/gRPC

PostgreSQL advanced

Event-driven architecture

AWS, Kubernetes, CI/CD

Security of financial data

Russian & English proficiency

Tools

NATS

Kafka

RabbitMQ

PostgreSQL tooling

Job description

At COLIBRIX ONE*, we're building advanced, AI-powered payment technologies that support Payment Service Providers (PSPs), Electronic Money Institutions (EMIs), and neobanks across the EU and the UK. As a fully licensed Electronic Money Institution (FCA Reference No. 927920) and holder of a Financial Institution Licence issued by the MFSA, as well as a principal member of both VISA and Mastercard, we provide comprehensive, real-world financial solutions that include:

• Global card processing
• Digital wallet infrastructure
• Cross-border merchant accounts
• Alternative payment methods (APMs)
• Corporate accounts for legal entities

We're a fast-growing team with a passion for innovation, security, and scalability. Our culture values curiosity, collaboration, and impact - and we're looking for talented professionals who are ready to shape the future of fintech.

At COLIBRIX ONE, your work directly powers the digital economy. If you're eager to solve meaningful challenges and build with purpose, we'd love to hear from you.

We're seeking an experiencedGo Engineerto join our team and contribute significantly to our payment gateway product. The ideal candidate will bring deep technical expertise, a collaborative mindset, and the ability to influence and mentor team members through knowledge and experience rather than formal authority.

What You Need to Succeed

• 5+ years of professional Go development experience, including 3+ years in fintech, banking, payments, or other transaction-critical systems
• Strong knowledge of distributed systems, microservices, and API design (REST and gRPC)
• Advanced PostgreSQL skills, including transactions, isolation levels, locking, indexing, migrations, and concurrency
• Experience designing reliable transactional systems using idempotency, retries, event deduplication, transactional outbox, sagas, and reconciliation
• Hands‑on experience with event-driven architectures and message brokers such as NATS, Kafka, or RabbitMQ
• Experience building and operating production services, including incident investigation, safe deployments, database migrations, and observability
• Practical knowledge of AWS, Kubernetes, and CI/CD
• Experience integrating with banks, payment providers, processors, AML/KYC, or anti-fraud platforms
• Understanding of security requirements for financial and personal data
• Ability to translate business requirements into technical solutions and independently drive implementation
• Strong communication skills and working proficiency in Russian and English

Banking Domain Experience

Hands-on experience in several of the following areas is highly valued:

• Ledgers, accounting flows, accounts, and balance management
• Holds, reversals, adjustments, reconciliation, and settlement
• SEPA, SWIFT, and ISO 20022
• Card transaction lifecycles and card scheme integrations

Nice to Have

• Experience with Temporal or a similar workflow engine
• Experience with NATS/JetStream, GitLab CI/CD, OpenTelemetry, Prometheus, Grafana, Loki, or Tempo
• Knowledge of event sourcing or append-only financial data models
• Familiarity with PCI DSS and GDPR
• Experience using AI coding tools for analysis, implementation, testing, or code review
  

What We Offer:

• Opportunity to shape the future of fintech solutions within a growing company
• Collaborative, horizontal team structure that values your expertise and ideas
• Continuous learning and development opportunities to enhance your skills and career growth
• Competitive salary and benefits package
• Flexible work arrangements to support work-life balance

* This position is offered within the COLIBRIXONE. Employment will be under the appropriate legal entity based on the role and location.