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 36 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