/ TEAMS · Senior Java / Spring Engineering
Source Java and Spring Boot developers for API integration, modernization and production applications.
2,000+ engineers in our active talent network · Regional recruiters
/ SYSTEM STACK
Java · Spring Boot · Spring MVC
JPA · Hibernate · Transactions
REST · Kafka · Events
Spring Security · OAuth2
Micrometer · Tests · CI/CD
/ AVAILABLE TO HIRE
Profiles show the experience we can source. Individual candidate availability is confirmed after enquiry.
Senior Java / Spring Boot Engineer — Enterprise Systems
Available12+ years of experience · Slovakia
Senior Java / Spring Boot Engineer — Enterprise Systems with 12 years in production systems, focused on Senior Java / Spring Boot Engineer — Enterprise Systems and Production systems.
Languages: Slovak, English B2+
Senior Java / Spring Boot Engineer — Enterprise Systems
Available7+ years of experience · Croatia
Senior Java / Spring Boot Engineer — Enterprise Systems with 7 years in production systems, focused on Production systems and Technical delivery.
Languages: Croatian, English C1
Mid+ Senior Java / Spring Boot Engineer — Enterprise Systems
Inquire availability6+ years of experience · Croatia
Senior Java / Spring Boot Engineer — Enterprise Systems with 6 years in production systems, focused on Technical delivery and Senior Java / Spring Boot Engineer — Enterprise Systems.
Languages: Croatian, English B2+
Senior Java / Spring Boot Engineer — Enterprise Systems
Inquire availability13+ years of experience · Croatia
Senior Java / Spring Boot Engineer — Enterprise Systems with 13 years in production systems, focused on Senior Java / Spring Boot Engineer — Enterprise Systems and Production systems.
Languages: Croatian, English B2+
Source Java and Spring Boot developers for API integration, modernization and production applications.
Discuss your hiring requirement ↗We assess relevant production responsibilities, evidence of implementation work and technical discussions with your team. A list of tools alone is not proof of experience.
Under staff augmentation the client usually directs the backlog and reviews. Team leadership and project-delivery ownership must be agreed separately.
The profiles indicate sourcing options, not verified available individuals. Availability, start date and fees are confirmed for the actual request.
Define the Java and Spring Boot versions, API contracts, persistence, database transactions, deployment model and integration responsibilities. We look for evidence of production changes, debugging and reliable software delivery rather than keyword-only CV matches.
/ Engineering teams
Onectus builds and contributes to complex product and enterprise software, with experience integrating engineers into established delivery teams. For Java/Spring searches we evaluate the candidate's actual services, business workflows, production incidents and API/data responsibilities against your architecture.
/ Technical specializations
The right senior engineer brings domain, persistence, reliability and maintainability decisions—not only familiarity with Java syntax or a starter template.
Modular boundaries, Spring Boot configuration, DI, controllers and domain services in existing applications.
Hibernate/JPA mapping, query efficiency, propagation, optimistic locking and database migrations.
REST design, validation, schema/version compatibility, partner APIs and resilient edge boundaries.
Kafka or other brokers, delivery semantics, outbox/idempotency, retry and message reconciliation.
Spring Security, OAuth2/OIDC, authorization, secrets, auditing and secure service communication.
Java LTS upgrades, JVM/GC diagnostics, Micrometer/Actuator metrics, testing and CI/CD.
/ Project scenarios
Separate domains and integration boundaries while keeping existing customer workflows running.
Diagnose JVM behavior, database contention, dependency timeouts and monitoring gaps.
Make messages traceable, retries idempotent and transactional outcomes consistent.
Plan supported Java versions, Spring migrations, compatibility tests and safe releases.
/ Practical evaluation
We evaluate architectural tradeoffs, service incidents and the candidate's concrete Spring/JVM responsibilities across the product lifecycle.
Why were configuration, dependency boundaries and transaction scopes chosen for that system?
How did Hibernate queries, locks, JVM allocations and thread pools behave under production load?
How were retries, message delivery, authorization and data consistency addressed?
What was personally led in code review, releases, incidents, observability and upgrades?
/ Sourcing process
Java/Spring versions, databases, security, messaging, system scale and team boundaries.
Search the active network and regional recruiters for verified enterprise Java responsibility.
Review actual JVM, API, transaction, deployment and architecture decisions.
Confirm interview criteria, availability, timezone, onboarding and expected ownership.
Profiles, availability and engagement terms are confirmed for each request.
/ Questions
Yes. Share Java and Spring versions, deprecated dependencies, security constraints, tests and production rollout requirements.
Yes. Include message delivery, idempotency, recovery and database transaction boundaries in the evaluation.
Yes. We can target senior contributors or technical leads who join a current team and work within its release and review processes.
We review JVM and persistence behavior, Spring architecture, production incidents, secure integration and ownership of changes.
/ Onectus · TEAMS
Tell us the technology, production responsibilities, experience level and working model. We'll activate the appropriate engineering sourcing channels.
