Principal Core Engineer

We are building the next generation of banking technology at Artea Bank – and we’re looking for a Principal Core Engineer to help design and build our own Core Banking platform from the ground up.

As one of the oldest and largest banks in Lithuania, we are entering a new chapter. Our ambition is to move beyond vendor-dependent banking technology and build our own modern, scalable and secure banking platform.

This is a hands-on role. You will be the first senior engineer on the core, working directly with the Head of Core Banking Engineering and the core development teams. Roughly half of your time is architecture – domain boundaries, service design, data and consistency models. The other half is code – the hardest components, the reference implementations, the reviews that set the bar. If you want to draw diagrams and hand them off, this is not the role.

• Design the Core Banking architecture: domain boundaries (customers, accounts, ledger, payments, transactions, products), service decomposition, integration contracts and event flows.
• Write production code – the ledger and posting engine, idempotency and outbox mechanics, the first service that every later service is copied from.
• Own the transaction and ledger model: double-entry posting, balances, value dating, end-of-day processing, reconciliation and audit trail.
• Set engineering standards through code, not documents – service skeletons, CI pipeline templates, observability baseline, ADRs for every significant decision.
• Design for failure: idempotency, exactly-once effects, retries, replay, sagas, disaster recovery.
• Build security and regulatory requirements (DORA, PSD2, GDPR, PCI DSS) into the design and the code from day one.
• Define the migration path from current systems: coexistence, data migration, parallel run, cutover.
• Work daily with the core development teams – pair, review, unblock, challenge.

• 10+ years of backend engineering, with a track record of designing and shipping distributed transactional systems to production. You have been on call for what you built.
• Expert-level Java and Spring Boot. You still write code every week and intend to keep doing so.
• Deep PostgreSQL knowledge: isolation levels, locking, indexing, partitioning, schema evolution under load.
• Kafka in production: partitioning, ordering guarantees, consumer semantics, outbox pattern, and an honest view of what exactly-once actually means.
• Financial data correctness as a reflex: money arithmetic, double-entry, append-only records, reconciliation. You know why floats and in-place balance updates are wrong.
• Hands-on experience migrating customers, accounts and balances from a legacy core to a new one – including migration strategy (phased, product-by-product or segment-by-segment), data mapping and validation, parallel run, reconciliation and cutover. You have lived through at least one such migration and know where it hurts.
• Domain-Driven Design applied in practice: bounded contexts, aggregates, service ownership – not just the vocabulary.
• Security-by-design: OAuth 2.0 / OIDC, mTLS, secrets management, audit logging.
• Operational maturity: OpenTelemetry-based observability, SLOs, incident handling, DR thinking.
• Testing discipline: contract tests, integration tests against real infrastructure (Testcontainers), automated reconciliation checks.
• Pragmatism: you can scope an MVP, say no to premature abstraction, and defend a decision in writing.
• Clear written and spoken English. You can explain a design to engineers and to risk and compliance colleagues.
• A builder mindset– comfortable creating something new rather than maintaining what exists.

Privalumai

• Experience building or integrating core banking platforms, payment systems or ledgers.
• Knowledge of banking domains: ledger, accounts, payments (SEPA, SEPA Instant, SWIFT/ISO 20022), cards.
• Working knowledge of DORA, PSD2, GDPR, PCI DSS, ISO 27001.
• Experience with Azure or another major cloud at production scale.
• Experience with AI-assisted or agentic software development workflows.

• The opportunity to build something from scratch. You’ll be shaping our own Core Banking platform, making foundational technology decisions that will influence the bank for years to come.
• Real ownership and influence. As our first Principal Core Engineer, you’ll work directly with the Head of Core Banking Engineering and have a significant voice in our technology strategy and architectural direction.
• A chance to shape the future of banking. Help transform one of Lithuania’s largest banks into a modern, technology-driven financial institution with ambitions to expand into international markets.
• A team you can help build. You’ll have the opportunity to influence how our engineering organisation grows, attract strong technical talent and establish engineering practices from the beginning.
• A modern technology environment. New infrastructure, a new codebase, Azure cloud, Java, Spring Boot, Infrastructure as Code and an ambition to embrace AI-driven engineering.
• An organisation that is changing. Joining Artea means more than just a new name – it means new ideas, perspectives and opportunities to help shape our culture from within.
• Achievements rooted in Lithuania. We’re especially proud to be a Lithuanian bank. We believe our country and our people are unique, and we want to build something that can make a difference beyond our borders.
• A personal benefits package. Health insurance, a pension savings programme, additional days off, flexible working hours, modern infrastructure – and that’s far from the complete list of benefits!
• Performance bonuses. Our employees can earn bonuses based on the performance of the bank, their team, and their own individual performance.