Spring Boot development company
Krapton builds and modernizes Java backends on Spring Boot: REST and event-driven services, Spring Security and OAuth2 setups, JPA data layers that hold up under load, and upgrades from Boot 2 and javax to Boot 3 and Jakarta EE.
- Senior engineers · IST + EST overlap
- NDA on day 1
- 24-hour reply
- Projects shipped
- 50+
- Code ownership
- 100%
- Client rating
- 4.8/5
- First reply
- 24h
What a Spring Boot engagement actually covers
As a Spring Boot development company, Krapton designs, builds and maintains Java services for teams that need a backend with mature libraries for security, data access and messaging. Spring Boot’s auto-configuration gets a service running quickly, but defaults are not decisions. Open Session in View is on unless you turn it off, lazy JPA associations produce N+1 queries that only show up with real data, HikariCP pool sizes rarely match the database’s connection limit, and Actuator endpoints can leak environment details if exposed without Spring Security rules. Our engineers settle those choices explicitly: Spring MVC on virtual threads or WebFlux, JPA or jOOQ for query-heavy modules, Kafka or RabbitMQ for events, Flyway for schema history. We also say when Spring Boot is the wrong tool, such as a handful of short-lived serverless functions where JVM cold starts dominate, or a team with no Java experience that will own the code long term. Every service ships with Testcontainers-backed integration tests, Micrometer metrics and a container image you can run anywhere.
Spring Boot development services
Spring Boot API development
REST and GraphQL APIs built with Spring MVC or Spring for GraphQL, Jakarta Bean Validation on inputs, problem-detail error responses, and OpenAPI documentation generated by springdoc so client teams can integrate early.
Microservices with Spring Cloud
Service boundaries drawn around business capabilities, Spring Cloud Gateway for routing, Resilience4j circuit breakers and retries, and configuration held in Kubernetes ConfigMaps or Spring Cloud Config instead of baked into images.
Spring Boot 3 migration
Upgrades from Boot 2.x covering the javax to jakarta package move, a Java 17 or 21 baseline, Spring Security 6 configuration rewrites, Hibernate 6 query changes and dependency conflicts, with OpenRewrite automating mechanical edits.
Data layer and performance
Spring Data JPA repositories with entity graphs and fetch joins that avoid N+1 queries, jOOQ or native SQL where reports demand it, HikariCP sized against the database, and Flyway migrations reviewed like application code.
Security and identity
Spring Security filter chains, OAuth2 resource servers validating JWTs from Keycloak, Auth0 or Entra ID, method-level authorization, and Actuator endpoints locked down so health checks work without exposing internals.
Event-driven integration
Spring for Apache Kafka and Spring AMQP consumers with idempotent handlers, dead-letter topics, the transactional outbox pattern for reliable publishing, and message schemas versioned through Avro or JSON Schema contracts.
Why teams choose Krapton for Spring Boot
Senior engineers, fixed scope, and code you own — the things agencies promise and rarely deliver.
Explicit choices over defaults
We document why a service uses MVC with virtual threads instead of WebFlux, or JPA instead of jOOQ, so the next engineer understands the tradeoff rather than inheriting an accident of auto-configuration.
Tests against real infrastructure
Integration tests run against PostgreSQL, Kafka and Redis in Testcontainers, while @WebMvcTest and @DataJpaTest slices keep the fast suite fast. Mocked repositories never stand in for real query behavior.
Observability from the first deploy
Micrometer metrics exported to Prometheus, OpenTelemetry traces across service hops, structured JSON logs with correlation IDs, and Actuator health groups wired to Kubernetes liveness and readiness probes.
Container-aware JVM tuning
Heap and garbage collector settings sized for container memory limits, layered jars or Cloud Native Buildpacks for lean images, and GraalVM native images evaluated only where startup time genuinely matters.
How a Spring Boot project runs with Krapton
01
Architecture review
We study your domain, traffic and data, then propose module or service boundaries, the persistence approach and messaging, with risks written down before any code starts.
02
Walking skeleton
A thin deployable slice goes first: one endpoint through security, database and the CI pipeline into staging, proving builds, migrations and observability work end to end.
03
Iterative delivery
Features land through pull requests reviewed for transaction boundaries, query plans and error handling, with sprint demos running on staging rather than on a developer laptop.
04
Hardening and handover
Load tests with Gatling or k6, dependency and CVE scanning, incident runbooks, and architecture decision records so your team can confidently own every service afterward.
The Spring Boot stack we build with
Spring Boot development: questions answered
What does a Spring Boot development company do for my product?
It designs, builds and operates Java backend services on Spring Boot, from API contracts through deployment. Our work covers architecture, Spring Security and identity integration, the data layer, messaging, CI/CD and production observability. Some clients bring a greenfield product; others bring an existing Spring codebase that needs an upgrade, performance work or new features added without breaking the services that depend on it.
When is Spring Boot the wrong choice?
Spring Boot is a poor fit when the team has no JVM experience and will maintain the code alone, or when the workload is a few short-lived serverless functions where cold starts dominate latency. GraalVM native images reduce startup time but add build complexity and reflection configuration. For a small CRUD API owned by a TypeScript team, Node.js or a lighter framework is often the more sensible path.
How do you migrate a Spring Boot 2 application to Spring Boot 3?
We migrate in stages, upgrading the platform before touching features. Java 17 or newer comes first, then OpenRewrite recipes handle the javax to jakarta package move, then security configuration is rewritten as SecurityFilterChain beans because WebSecurityConfigurerAdapter no longer exists. Hibernate 6 changes some query behavior, so integration tests run against the real database at each step. Third-party libraries still on javax are the usual blockers.
Should our Spring Boot services use WebFlux or virtual threads?
For most new services, Spring MVC on Java 21 virtual threads is the simpler option and handles high concurrency for blocking I/O well. WebFlux still makes sense for streaming, backpressure-heavy pipelines or teams already fluent in Reactor. Mixing the two styles carelessly is the real risk: a blocking JDBC call inside a reactive chain stalls the event loop, a common cause of unexplained latency.
What decides the cost of a Spring Boot development project?
Cost follows scope and risk rather than the framework itself. The main drivers are the number of services and integrations, legacy data that must be migrated, identity and compliance requirements, expected traffic and uptime targets, and the seniority mix the work needs. For an upgrade, test coverage and the age of dependencies matter most. We scope these drivers in a discovery phase before proposing a plan.
Ready to build? Tell us what you have in mind.
Send a short brief and a senior engineer will reply within one business day with next steps — no sales fluff.