TRCI-26-04179

Java Developer / Backend Architect (Spring Boot, Migration & Routing Services)

Contract assignment in Stockholm for a senior Java developer with strong architectural capabilities to design and implement Spring Boot backend services used in a customer migration program. The work focuses on customer identification and identifier extensibility, stack/migration-status lookup, routing/redirection decisions, and batch processing to load and maintain migration data. You will build secure, scalable, observable microservices (OAuth2/OIDC/JWT), implement caching/validation/error handling, and deliver automated tests and CI/CD-ready containerized deployments (Docker/Kubernetes). The role also expects you to guide architectural decisions and align services, integrations, and data flows with long-term maintainability.

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Position summary

Location: Sweden
Workplace: On-site
Employment: Contract
Experience: Minimum 5 years and Maximum 10 years

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Role overview

Why This Role Matters.

Your Impact

Deliver Enterprise Value

Help organisations solve complex business problems through modern technology, consulting expertise and measurable outcomes.

Collaboration

Work Across Teams

Collaborate with consultants, architects, engineers and client stakeholders throughout the project lifecycle.

Growth

Learn Continuously

Gain exposure to enterprise technologies, certifications, mentoring and real-world project experience.

Career Path

Grow With Ubique

Build a long-term consulting career with opportunities to take on greater responsibility and leadership over time.

Responsibilities

What You'll Be Doing.

Every role at Ubique contributes directly to solving meaningful business challenges for our clients.

Java Developer with strong architectural capabilities

Design and develop Java/Spring Boot REST APIs to determine the appropriate customer stack based on Customer ID and other stack-related identifiers.

Build flexible identification mechanisms that can be extended with additional identifiers as business and migration requirements evolve.

Implement batch processing solutions for loading, updating, and maintaining customer migration and stack information.

Develop services for tracking which customers and associated identifiers have migrated and their current migration/stack status.

Provide backend APIs supporting Customer Identification UI functionality.

Enable UI/application redirection based on customer identification, stack assignment, and migration status.

Expose customer stack and migration status to frontend applications where required.

Implement routing and lookup capabilities supporting customers throughout the migration window, including transitional states while migration is in progress.

Ensure APIs are highly available, secure, scalable, observable, and resilient.

Implement appropriate caching, validation, error handling, logging, monitoring, and auditability.

Create automated unit, integration, and API tests and contribute to CI/CD pipelines.

Technology stack

Tools & Technologies.

The platforms and technologies you'll use to build modern, enterprise-grade solutions.

Java

Required

Java 10+

Required

Spring Boot

Required

Spring Framework

Required

REST

Required

Microservices

Required

Spring Data JPA

Required

Hibernate

Required

SQL

Required

RDBMS

Required

Spring Batch

Required

OAuth2

Required

OpenID Connect

Required

OIDC

Required

JWT

Required

JUnit

Required

Mockito

Required

Testcontainers

Required

Maven

Required

Gradle

Required

Requirements

Skills & Experience.

We value curiosity, collaboration and continuous learning. If you don't meet every requirement but believe you can make an impact, we'd still love to hear from you.

Essential

Required Qualifications

Java 10+

Spring Boot

Spring Framework

REST API design

Microservices architecture/design

Spring Data JPA and/or Hibernate

SQL

Relational databases

Batch processing (preferably Spring Batch)

Design of lookup and routing services

API security (OAuth 2.0, OpenID Connect, JWT)

Unit and integration testing (JUnit, Mockito, Testcontainers or equivalent)

Maven or Gradle

Git

CI/CD

Docker

Kubernetes

Cloud-native deployment practices

Observability: logging, monitoring, metrics, distributed tracing

Architecture skills: define target architecture, evaluate trade-offs, establish design principles, guide team

Preferred

Nice to Have

Large-scale customer/platform migrations

Supporting old and new application stacks simultaneously (dual-run/strangler patterns)

Customer identity/identifier mapping and resolution

Migration state management (e.g., NOT_MIGRATED, MIGRATION_IN_PROGRESS, MIGRATED, rollback/failure handling)

Event-driven architecture

Kafka (or similar messaging)

Redis (or similar caching)

Azure and/or AWS

API gateways

Traffic routing solutions

High-volume batch processing and reconciliation

What you'll gain

More Than Just A Job.

We're committed to helping every team member grow professionally, personally and technically while working on meaningful projects.

Global Exposure

Collaborate with international clients and multicultural teams on enterprise programmes.

Continuous Learning

Expand your expertise through mentoring, certifications and hands-on project experience.

Career Growth

Take ownership, develop leadership skills and grow your consulting career over time.

Flexible Working

Hybrid and remote collaboration designed around trust and delivering exceptional outcomes.

People First

Join a supportive culture where collaboration, respect and long-term relationships come first.

Enterprise Projects

Work on meaningful technology initiatives for leading organisations across industries.

Apply

Apply for Java Developer / Backend Architect (Spring Boot, Migration & Routing Services)

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