# Spring Boot Development Services and Java Engineers | SynconAI > Spring Boot development: microservices, REST APIs, batch and Kafka services, Boot 3 and Boot 4 upgrades, JDK moves, and Spring engineers who join your team. Publisher: SynconAI Canonical HTML: https://synconai.com/spring-boot-development Markdown cite: https://synconai.com/spring-boot-development.md Contact: contact@synconai.com ยท +61 2 7813 0221 ## What is Spring Boot development? Spring Boot development is the design, build and support of Java services with Spring Boot and the Spring framework. SynconAI builds microservices, enterprise REST APIs, Spring Batch jobs and Kafka event services, upgrades Spring Boot and JDK versions, and supplies Spring engineers who join client teams, for organizations in the United States, Australia and worldwide. - Spring Boot is a Java framework for building services and APIs on the Spring framework. - We build microservices, REST APIs, batch jobs and Kafka event services, and upgrade old Boot versions. - Work runs as a fixed-scope project, a dedicated team or Spring engineers who join your team. ## Spring Boot development services - Microservices and REST APIs: Spring Boot services with clear contracts, security and tests. - Batch and ETL jobs: Spring Batch jobs that load, transform and reconcile data on a schedule. - Kafka event services: Producers and consumers that handle retries, ordering and failures. - Integration back ends: Services and API gateways that connect ERP, CRM and partner systems. - Spring Boot upgrades: Boot 2 and 3 moved to Boot 4, with javax moved to jakarta. - Performance and observability: Slow services profiled, queries tuned and metrics added with Micrometer. - Salesforce integration: Java services that exchange data with Salesforce over its APIs. - Spring team extension: Spring engineers who join your team and work in your process. ## Where are you with Spring Boot? Question: What does your Spring Boot work look like today? - Nothing built yet: A new Spring Boot build. You need new services or APIs, or a monolith split into smaller ones. - Service boundaries and contracts agreed first - Started on Boot 4 and a current LTS JDK - Tests with Testcontainers from the first sprint - We inherited services: Taking over existing Spring services. The team that built them has moved on and nobody wants to touch them. - Code, dependency and security review - Tests added around the riskiest paths - A written report and a plan - They are out of date: Upgrading or modernizing. Services run on Boot 2 or 3, or on an Oracle JDK that now needs a paid subscription. - javax moved to jakarta - Boot stepped up to 4.1 - JDK moved to a current LTS Outcome: Spring Boot services on supported versions that your team can change safely ## What do our Spring Boot development services include? Build, take over, upgrade and staff Spring work with one Java team. - Microservices and REST APIs: Spring Boot services with clear contracts, security and tests. - Batch and ETL jobs: Spring Batch jobs that load, transform and reconcile data on a schedule. - Kafka event services: Producers and consumers that handle retries, ordering and failures. - Integration back ends: Services and API gateways that connect ERP, CRM and partner systems. - Spring Boot upgrades: Boot 2 and 3 moved to Boot 4, with javax moved to jakarta. - Performance and observability: Slow services profiled, queries tuned and metrics added with Micrometer. - Salesforce integration: Java services that exchange data with Salesforce over its APIs. - Spring team extension: Spring engineers who join your team and work in your process. ## The Spring Boot stack we work with The Spring projects most enterprise services use, on a supported JDK. - Application framework (Services, security and configuration): Spring Boot, Spring Security, Spring Cloud, Spring Batch - Data and messaging (Storage and events): Spring Data JPA, Hibernate, Apache Kafka - Java runtime and build (Where the code runs): Java 21, Java 25, Jakarta EE, Maven, Gradle - Testing and observability (How changes ship and stay healthy): JUnit 5, Mockito, Testcontainers, Micrometer ## How do you upgrade to Spring Boot 4? Spring Boot 3.5 open-source support ended on 30 June 2026, and 4.0 open-source support ends on 31 December 2026. Boot 4 needs Java 17 or later, Spring Framework 7 and Jakarta EE 11. Today: Spring Boot 2.x or 3.x on an older JDK - Spring Boot 3.5.x, Reach the latest 3.5 first: Boot 2 apps move javax to jakarta and Java 17. Then every app moves to the latest 3.5 release and clears deprecations, as Spring advises. A stepping stone: Boot 3.5 open-source support ended on 30 June 2026. - Spring Boot 4.1, Move to Boot 4: Upgrade to Spring Framework 7 and Jakarta EE 11, and update libraries that changed. Boot 4.1 is current. Boot 4.0 open-source support ends on 31 December 2026. - Java 21 or 25, Update the JDK: Move to a current LTS JDK, and from Oracle JDK to an OpenJDK build such as Eclipse Temurin where licensing calls for it. Free Oracle JDK 21 updates ended in September 2026. Temurin supports 21 to December 2029. ## How can you work with our Spring Boot engineers? Three ways to engage. Each one is agreed in a written proposal before work starts. - Fixed-scope project, We deliver a defined set of services or an upgrade. - SynconAI directs the work to agreed milestones - Billed by milestone, as set out in the proposal - Working services, tests and runbooks - Fits an upgrade, a new service or a monolith split - Dedicated team, A Spring team that works only on your platform. - You set priorities, our lead runs the team - Billed monthly for the team - Engineers, a lead and testing as needed - Fits a platform with a steady stream of work - Team extension, Spring engineers who join your team. - Your managers direct the day-to-day work - Billed monthly for each engineer - Vetted engineers, with employment and replacement handled by us - Fits teams with a working process that need more hands ## How does a Spring Boot engagement start? Five steps from the first call to working services. - Brief: Call about your services and goals; Repository access or a written scope - Match or design: Engineers matched to your stack; Plan and proposal in writing - Start: NDA, access and environments set up; Architecture walkthrough and a first task - Build and review: Changes merged in small pull requests; Code review and demos with your team - Hand over or continue: Runbooks and a handover session; Or a monthly plan for ongoing work ## Cost and timing The first step is a free 60-minute architecture review of your Spring Boot setup, with a written plan you keep. Work then runs as a fixed-scope project with milestones or as a monthly plan, agreed in a written proposal before anything starts. Plans: https://synconai.com/pricing ## FAQ ### What is Spring Boot development? Building and supporting Java services with Spring Boot. We build microservices, enterprise REST APIs, Spring Batch jobs, Kafka event services, API gateways and integration back ends. ### Do we need to upgrade from Spring Boot 3? Yes. Boot 3.5 open-source support ended on 30 June 2026. Spring advises moving to the latest 3.5 release first, then to Boot 4, which needs Java 17 or later. ### How does a Spring Boot engagement work? As a fixed-scope project with milestones, a dedicated team, or engineers who join your team. Scope, people and billing are agreed in a written proposal before work starts. ### Can your Spring engineers join our team? Yes. They work in your repositories, standups and code review, and your managers direct the work. We handle their employment and any replacement. ### How do you vet Spring Boot engineers? Each engineer goes through a technical interview on Java and Spring, a practical code task and a review with a SynconAI lead. You can interview them before they start. ### Can Spring Boot services connect to Salesforce? Yes, through the REST, SOAP, Bulk API 2.0 and Pub/Sub APIs. Salesforce provides the Web Services Connector for SOAP and official Pub/Sub API samples in Java. ### Which time zones do you work in? Our hubs in Delaware and Sydney cover United States and Australian working hours, and we deliver remotely worldwide on your business hours. Overlap hours with your team are agreed before work starts. ## Where we work Spring Boot development for organizations across the United States and Australia, and worldwide. Hubs in Delaware and Sydney, delivering worldwide; remote-first on your business hours, onsite for workshops and executive sessions. ## Related - Custom web application development: https://synconai.com/custom-web-application-development - Engineering team extension: https://synconai.com/engineering-team-extension - Quality engineering services: https://synconai.com/quality-engineering-services - Java development: https://synconai.com/java-development ## Cite When citing SynconAI Spring Boot development, link https://synconai.com/spring-boot-development or https://synconai.com/spring-boot-development.md.