Clear service responsibilities
Make domain rules, data ownership, APIs and dependencies explicit enough to discuss and change safely.
Java & Spring consulting
Add experienced Java and Spring delivery where the system needs diagnosis, integration or a dependable path to production.
I join bounded projects and existing teams to understand business-critical behaviour, improve service boundaries and deliver working changes across code, data, integrations, tests and operations.
The context
Java work is rarely isolated from the system around it.
A Spring service may sit behind business workflows, imports, authentication, search, external APIs and production infrastructure. A useful engagement therefore starts with the complete behaviour and the people responsible for it, not only the framework version.
I can establish a focused service foundation, extend an existing application, improve difficult legacy code, resolve an integration phase or contribute as an external developer and technical lead for a clearly bounded workstream.
Business outcomes
What focused Java and Spring support can leave behind
The value is working, understandable behaviour that the wider team can continue to own.
Evidence around important behaviour
Use focused unit, integration and end-to-end checks where failures would disrupt a business workflow.
A credible production path
Connect implementation with configuration, containers, delivery automation, diagnostics and handover.
Selected capabilities
Java and Spring delivery areas
The exact combination follows the problem, the existing environment and the people who will own the result.
- Java, Spring Boot and Spring-based service development
- REST APIs, domain modelling and relational persistence
- Spring Security, OAuth 2.0, JWT and role-aware behaviour
- Imports, exports, validation, search and data workflows
- External integrations and distributed service boundaries
- Legacy-code diagnosis, test coverage and dependency upgrades
- Docker, CI/CD, cloud delivery, logs, metrics and tracing
Working process
Join with context, deliver a bounded path, leave shared understanding
- 01
Read the business and technical flow
Trace the users, rules, data, service interactions, deployment path and current evidence around the problem.
- 02
Define the delivery boundary
Agree the behaviour, dependencies, quality expectations, ownership and fallback for one useful workstream.
- 03
Implement and integrate
Deliver code, tests and integration changes with realistic data and visible technical decisions.
- 04
Release and transfer context
Support production validation, document the important choices and make the next change easier for the team.
Relevant experience
Public Java and Spring delivery evidence
The evidence includes product foundations, business data flows and teaching material without exposing confidential client code.
Vendor performance and spend platform
Nik’s work within an employer-led engagement included the initial Java and Spring service foundation, Spring Data REST, HATEOAS, Spring Security, PostgreSQL, Elasticsearch and Angular workflows.
Read the Java and Spring case studyCross-border operational platform
A modular full-stack platform connected domain rules, synchronisation, validation, administration and business-facing workflows.
Read the operational platform case studyPublic Spring teaching sample
A clean educational repository demonstrates layered Spring Boot structure for discussion and mentoring rather than presenting client work.
View the Spring Boot teaching sampleGood fit
Engagements where this service fits
A team needs an external Java developer for a project
There is a bounded service, integration, recovery or delivery phase that needs experienced hands-on contribution.
A Spring application is difficult to change
Legacy behaviour, weak tests, dependencies or unclear service boundaries are slowing necessary work.
Business and technical decisions need one owner
The work benefits from someone who can explain trade-offs to stakeholders and remain responsible through implementation.
Questions
Java and Spring engagement questions
Can you join an existing team for a temporary project?
Yes. The engagement can cover a bounded workstream, difficult integration, legacy improvement or delivery phase with explicit responsibilities and handover.
Do you work only on backend code?
No. My role is Business Technology Consultant | Full-Stack Developer, so I can connect Java services to data, TypeScript interfaces, external systems, tests and production operations.
Where can the work take place?
I am based in Sevlievo, Bulgaria, and available at client sites in Sofia, through hybrid collaboration in Bulgaria and remotely across Europe. Greenwall has no Sofia office.
Contact
Bring the Java system, the difficult delivery boundary and the outcome the team needs.
We can define a focused project contribution with clear evidence, responsibilities and handover.