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Kultrix Java developers build the kind of backend systems that enterprises depend on. Spring Boot microservices, RESTful and event-driven APIs, Hibernate-powered data layers, and CI/CD pipelines that deploy with confidence.
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Senior Engineers Only
7+ Years Experience
NDA
EXPERTISE
WHAT WE DO
We build production-grade REST APIs with Spring Boot, controllers, services, repositories, validation, exception handling, and OpenAPI documentation that keeps clients in sync with the contract.
We design Java microservice architectures with Spring Cloud, implement service discovery, API gateway patterns, distributed tracing with Micrometer, and inter-service messaging via Kafka.
We model JPA entities with Hibernate, write optimised JPQL and native queries, manage schema evolution with Flyway, and tune connection pools for high-concurrency enterprise workloads.
We implement event-driven architectures with Apache Kafka, producers, consumers, stream processing with Kafka Streams, dead-letter handling, and schema registry integration.
We configure Spring Security for OAuth 2.0, JWT authentication, RBAC, and SAML SSO, meeting enterprise compliance requirements for authentication and authorisation.
We assess and modernise monolithic Java EE applications, strangler-fig migration to Spring Boot microservices, Java version upgrades, and performance improvements without big-bang rewrites.
WHO THIS IS FOR
Whether you are a startup or enterprise, we have the right engagement for you.
Fast-track your MVP with senior talent. Launch on time and within budget.
Improve performance, UX, and features of your existing product with expert help.
Augment your team with senior specialists to accelerate feature delivery.
OUR APPROACH
Choose the cooperation format that best fits your business goals and development velocity.
Fast launch to test your idea and gather user feedback with minimal investment.
What's included
Timeline Typically 9-16 weeks
Complete cycle from initial strategy and design to final launch.
What's included
Timeline Typically 20-40 weeks
Scale your team with expert developers to accelerate development.
What's included
Timeline Flexible / Long-term
OUR HIRING PROCESS
Tell us about your project goals, timeline, and team needs. We'll set up a free consultation to dive deeper into your requirements.
Based on your project, we recommend the ideal team structure, engagement model, and technology approach - tailored to your goals and budget.
We handpick the best-fit professionals from our senior talent pool. You'll meet them, review their experience, and give the green light.
Your team onboards within 48 hours. We align on workflows, set up communication, and start delivering results from week one.
As your project evolves, we scale your team, add new specialists, or adjust scope - all within your existing partnership.
INDUSTRIES
Our Java Developer professionals build solutions across various sectors.
Data-driven commerce solutions that improve journeys, boost sales, and optimize operations.
Data-driven commerce solutions that improve journeys, increase sales, and optimize operations.
Reliable medical platforms that protect patient data, simplify workflows, and support clinical accuracy.
Product-driven platforms that enhance workflows, automate processes, and scale with your business.
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Expert professionals ready to join your team and deliver results.
CASE STUDIES
Testimonials
What impressed us most was how Kultrix handled the full stack - frontend, backend, and mobile - with one cohesive team. Communication was clear, delivery was predictable, and the final product exceeded what we initially scoped.
Co-CEO
Kultrix built both our web platform and mobile app from scratch. Their team understood the complexity of our industrial workflows and translated them into clean, intuitive interfaces. We launched on time and our operators adopted the tools immediately.
Co-CEO
Kultrix handled everything for us - landing page, dashboard, mobile app, and even a Chrome extension. Having one team own the entire product surface meant everything felt connected and consistent. They shipped fast and the quality speaks for itself.
CEO, Ping Proxies
Kultrix has been our go-to partner for multiple projects - from marketing websites to full mobile applications and backend systems. They scale up when we need speed and maintain consistency across every project. Reliable, fast, and technically strong.
CEO, Volume Apps
Working with Kultrix on our mobile app and backend was seamless. They brought strong product thinking to every sprint, not just code. When priorities shifted, they adapted quickly without losing momentum. Exactly the kind of partner a product team needs.
Product Lead, Pelago
We needed a team that could handle mobile development, server infrastructure, and AI features all at once. Kultrix delivered on all three fronts. Our fitness platform went from concept to production in under four months with zero compromises on quality.
CEO, Fitblast
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FAQ
Java remains the dominant language for enterprise software because of its ecosystem maturity, strong tooling, and the depth of talent available. Kultrix Java developers bring senior-level Spring Boot expertise, understanding of enterprise integration patterns, and the discipline required for mission-critical systems - not just the ability to write code but the judgement to make the right architectural decisions under real constraints.
Standard placement is 48 hours from contract signing. Java is one of our deepest talent pools. For developers with specific enterprise experience - SAP integrations, mainframe migration, financial services compliance - one week is more realistic.
Our developers work primarily with Java 21 LTS and Java 17 LTS. They are current with modern Java features - records, sealed classes, pattern matching, virtual threads (Project Loom), and the new String methods. For projects locked to older Java versions (8 or 11), our developers adapt and work within the constraint while identifying upgrade paths.
Spring Boot is our primary framework for new Java projects - its ecosystem, community, and developer experience are significantly ahead of Jakarta EE for most use cases. Our developers are also experienced with Jakarta EE (JPA, CDI, JAX-RS) for projects running on traditional application servers like WildFly or OpenLiberty, which remain common in regulated industries.
We follow Domain-Driven Design principles to identify service boundaries, use Spring Cloud for service discovery and configuration management, implement API gateway routing, and choose between synchronous (REST, gRPC) and asynchronous (Kafka, RabbitMQ) communication based on the coupling and latency requirements of each interaction. We document architectural decisions with ADRs.
Yes. We regularly join mature Java codebases - adding features, fixing performance issues, upgrading Spring Boot versions, migrating from XML configuration to annotation-based or Java configuration, and improving test coverage. We start with a code review and produce a prioritised improvement plan before writing new code.
We use Flyway for all schema migrations - versioned SQL scripts stored in source control, applied atomically at startup, and rolled back safely when needed. We plan migrations to be backward-compatible wherever possible, allowing zero-downtime deployments. For complex data transformations, we separate schema changes from data migrations and apply them in stages.
Testing is mandatory on every Kultrix Java engagement. We write unit tests with JUnit 5 and Mockito, integration tests with Spring Boot Test and Testcontainers against real database instances, and contract tests with Spring Cloud Contract for inter-service APIs. Test coverage targets are agreed at project start and enforced in CI.
Yes. Apache Kafka integration is a standard capability for our Java team. We configure Spring Kafka producers and consumers, implement retry logic with dead-letter topics, use Avro schemas with Confluent Schema Registry for message compatibility, and implement Kafka Streams for real-time stream processing - including stateful aggregations and windowed operations.
We profile with async-profiler and VisualVM to identify CPU and memory hotspots before optimising anything. Common improvements include connection pool tuning (HikariCP), JPA N+1 query elimination, heap size and GC algorithm configuration (G1GC vs ZGC), and virtual thread adoption for I/O-bound services on Java 21+. We measure rigorously and present before/after benchmarks.
Yes. We write optimised Dockerfiles for Spring Boot applications - using layered JARs for better layer caching, setting appropriate JVM flags for container environments, and configuring health actuator endpoints for Kubernetes liveness and readiness probes. We also write Helm charts and configure horizontal pod autoscaling for production deployments.
Monthly retainer and time-and-materials models are both available. Enterprise Java projects often involve a mix of feature development and ongoing maintenance, making retainer engagements particularly well-suited. Both models include weekly progress reports, transparent timesheets, and a dedicated account manager. Minimum engagement is one month.
