Java Tech Lead

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 and work closely with the client's technical leadership. AI-assisted development is part of everyday engineering.

What you will do

Lead and mentor a team of 3–6 engineers while staying hands-on: at least half of your time is production code

Shape the architecture of a new event-driven backend and own technical decisions in your area

Own code quality: code reviews, testing standards, secure coding practices

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

Make sure the solution meets security and regulatory requirements, including PCI DSS

Create and onboard AI powered SDLC process and help the team adopt them with clear rules for review and testing

Deliver features end to end, from technical design to production support

Break down scope, estimate and plan delivery together with Product Manager

Be the main technical point of contact for client stakeholders

What you bring

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

2+ years as a Tech Lead or Team Lead of 3+ engineers, while still writing code

FinTech background is mandatory: commercial experience on banking, payments or lending products

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

Solid knowledge of concurrency and transactions: ACID, isolation levels, optimistic and pessimistic locking

Strong relational database skills (PostgreSQL preferred), JPA / Hibernate

Experience integrating external APIs and providers: retries, timeouts, idempotency, consistent error handling across layers

Designing secure public APIs for external integrations: authentication, authorization, platform boundaries

Architecture know-how: DDD, Clean or Hexagonal architecture; you can design a system from scratch and defend the decisions

Hands-on AWS (or another major cloud), Docker and CI/CD, including API versioning and database migrations

Strong testing culture: unit, integration and contract tests (JUnit, Mockito, Testcontainers)

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 lead technical discussions with the client

Nice to have

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

Visa or Mastercard integrations and scheme certification

PCI DSS in practice; HSM, key management, tokenisation for digital wallets

Ledger systems and double-entry accounting

Bank transfer and direct debit integrations (SEPA or other domestic payment rails)

Kotlin, Kubernetes, Terraform; schema evolution with Avro or Protobuf

Work in a regulated financial environment

Threat modelling

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