Java development services
We deliver Java development services for companies building enterprise Java systems. We design transactional platforms, Spring back ends and integration layers, and modernize inherited estates with architecture your developers can maintain.
01Capabilities
Enterprise Java platforms and integrations
Java platform architecture connects the domain model, persistence and contracts other systems depend on. For an inherited estate, runtime and dependency work sits within legacy modernization.
- Operations
Operations and logistics platforms
Order management, dispatch, inventory and scheduling are central to our logistics and transportation work. We model their transactional rules and design how your developers will change and maintain them.
- Back ends
Enterprise back ends and API contracts
We build Spring Boot services with domain models mapped through JPA and Hibernate to PostgreSQL. We design the API contract before implementation so consuming teams can work against an explicit interface.
- Integration
Integration layers between business systems
Our platforms and integration work connects an ERP, a warehouse system and a payment provider behind explicit contracts. Idempotency, retries and reconciliation address repeated requests and interrupted exchanges.
- Migration
Evolving Java 8 and inherited JVM estates
We evolve Java 8 estates and monoliths by addressing runtime, build and dependency compatibility before redesign. Work on Java EE code includes application-server and Jakarta EE namespace compatibility. We choose a supported target against the JDK provider and framework dependencies, then establish module boundaries before considering service extraction.
02Case studies
Two Java systems we wrote end to end
We built moving software from scratch and modernized a rental platform with NFC/RFID time tracking and CRM integrations.
See all case studies
LogisticsCustom software for a US moving companyAn end-to-end SaaS platform for managing household moves and every business operation of a logistics company.Built from scratchAn end-to-end SaaS for household moves and the operations behind them
LeisureSaaS modernization for a paddle sports center in CaliforniaA kayaking and paddleboard rental business in the Santa Barbara area wanted one system for equipment, customers, time and billing. That system is Adventure Rental System.15-20%Increase in revenue
03Fit
Six situations, and the call we would make in each
We choose the platform against transactional rules, integration needs and the team that will maintain it. For an existing Java estate, the recommendation also depends on support, required changes and the operating model.
| Your situation | What we recommend |
|---|---|
| A transactional core with shared contracts and a long service life | Use JavaUse Java to make domain rules, persistence boundaries and API contracts explicit. We plan the upgrade path and how future teams will maintain the system. |
| An application-server estate with Java EE javax packages and server-managed behaviour | Java EE estate workOur Java EE page covers server-managed transactions, application-server compatibility and the javax-to-jakarta package migration. That work is scoped alongside JDK compatibility. |
| An event-driven workload with bursty traffic and cold-start constraints | Lighter or serverlessAssess a lighter runtime or managed serverless deployment against startup behaviour, traffic pattern and operational responsibility. The workload and hosting model determine the cost. |
| A data or machine-learning pipeline | Python for data workChoose Python where its data and machine-learning libraries fit the pipeline. We assess the contracts connecting it to the rest of the platform. |
| A product whose domain changes frequently | Your fastest stackUse the stack your developers can iterate and maintain confidently. We assess the API and data requirements before committing to more specialized architecture. |
| A stable Java estate on a supported JDK and framework | Keep it stableKeep the estate maintained when it meets the business requirements. Plan modernization around a support change, compatibility constraint or new capability that requires it. |
Scope
We own the architecture, failure modes and upgrade path, including how your developers will maintain the system. unicrew has been building software since 2012, with 100+ senior in-house engineers across six countries. The work runs under an ISO 27001:2022 certified information-security management system.
On a Java monolith, we agree the domain boundaries before anything is split. We build them as module boundaries inside one deployable first. If they hold through two quarters of real feature work, splitting out a service becomes a small change.
Oleksandr TrofimovChief Technology Officer, unicrew04Delivery
The sequence we run before touching inherited code
We assess inherited Java code as a running system before redesigning it. The sequence establishes the current behaviour, compatibility and module boundaries needed for the next change.
- Map the running systemWe map deployed topology, JVM and framework versions, the data model, scheduled jobs and integrations. You receive a written map of the running system, including components whose ownership needs confirming.
- Test the critical domain behaviourWe write characterisation tests around business-critical behaviour before refactoring. You receive a test suite that runs in your pipeline and stays yours.
- Update runtime, build and dependenciesWe assess the JDK distribution and support entitlement alongside framework and dependency compatibility. The agreed changes establish a supported runtime, a current Maven or Gradle build and dependencies that can receive patches.
- Set module boundaries before extractionWe define module boundaries inside the monolith before deciding on microservices. You receive those boundaries in code and a written extraction order tied to business needs. We verify each change through QA and test automation.
05Client voices
Two clients on what the work was like
We’ve seen a 15-20% increase in revenue, which is through the efficiency gains and the ability to accurately track time on a permanent basis rather than just by a quarter hour or an hour. I’ve worked with a lot of development teams over the years and these guys have been the best. It’s nice to finally find a team that we can work with.
unicrew successfully found a candidate for us. The team also provided a good service around the onboarding process and the contract. Overall, the services were very good. unicrew had fine solutions when problems came up. It was a pleasant experience working together. unicrew met deadlines and stayed on budget.
06Stack
The rest of the stack a Java system needs
The JVM platform sits alongside data storage, packaging and orchestration. The linked technologies distinguish those choices from Java EE server work and Kotlin language decisions.
07Questions
Questions about Java systems and delivery
Set the framework, runtime and delivery responsibilities for a Java engagement.
Yes. Our senior Java engineers work on defined delivery scopes and ongoing systems, with architecture responsibility.
An architect outside the delivery team reviews the architecture decisions. Our QA and test automation practice supports verification of the agreed changes.
Choose managed teams for ongoing Java work with delivery coordination, or custom software development for a defined outcome.
We work on Java 8 estates and agree any upgrade against your release calendar.
Support depends on the JDK distribution, provider entitlement and related frameworks. We review those alongside libraries and deployment constraints, then sequence the required runtime, build and dependency changes.
We choose a supported long-term-support (LTS) release against the JDK distribution, framework and application-server compatibility.
Java 21 is one candidate. For Java 8 and Java 11 estates, we check support entitlement and libraries before selecting the target. The application server and namespace move are the scope of our Java EE page.
We use Spring Boot for almost every new system we start, and consider Jakarta EE where application-server responsibilities are part of the estate.
The choice accounts for framework compatibility, existing operations and the developers who will maintain the system. Our technology advisory work covers that platform decision.
Yes. We take over inherited Java codebases by first mapping the running system and testing its critical paths.
That assessment covers deployed versions, topology, data, scheduled jobs and integrations. It establishes the baseline for agreeing changes and the handoff to your developers.
We cover Java code, build pipelines, JVM tuning, observability and the deployment path.
Where your own platform team owns operations, we work to their standards. Our DevOps consulting covers work where operations is the primary scope.
We start with a technical scoping conversation, usually with the engineer who would work on the system.
For an existing system, we ask for repository read access beforehand to scope architecture, runtime and dependency work. Most engagements start within two to four weeks.
Java work is quoted per agreed scope and delivery model.
- Time and materials: billed hourly and quoted per project.
- Fixed price: outcome based and quoted per project.
- Team extension: billed monthly per team member.
We agree fixed price after the initial technical assessment defines the outcome and boundaries.
Build and evolve your enterprise Java system
Tell us which business workflows the system must support and what changes you need. We will assess the architecture and runtime constraints, then recommend the first scope.