Senior Java Developer (API SDK)

TL;DR

Senior Java Developer (API SDK): Building and evolving a Spring Boot-based framework for secure, resilient, and high-performance APIs with an accent on platform integration, developer experience, and observability. Focus on designing reusable framework components, integrating service mesh and cloud platforms, and solving complex security, compatibility, and distributed-systems challenges.

Location: Bucharest, Romania; hybrid work with the option to work from home or the office.

Company

hirify.global Romania is ING’s technology and operations hub, providing software development, data, risk, compliance, audit, and retail operations services to ING units worldwide.

What you will do

• Develop and maintain the API SDK and core Toolkit components.
• Deliver framework capabilities for security, resilience, observability, and backward compatibility.
• Integrate the SDK with container platforms, messaging systems, API gateways, service discovery, and service mesh solutions.
• Design intuitive APIs and configuration interfaces, supported by documentation, testing tools, and reference implementations.
• Support development teams using the SDK and contribute to community-driven improvements.

Requirements

• 5+ years of Java development experience and 3+ years working with distributed systems and microservices.
• Experience designing reusable frameworks, libraries, or platform components.
• Knowledge of Java, Spring Boot, Maven, JVM fundamentals, microservices, resilience patterns, and observability.
• Experience with security technologies such as OAuth2, JWT, PKI, mTLS, and secure coding practices.
• Degree in Computer Science or equivalent practical experience.
• Strong technical communication, documentation, and developer-platform support skills.

Nice to have

• Experience building developer-facing frameworks or SDKs.
• Knowledge of Kafka, event-driven architectures, API gateways, OpenAPI/Swagger, and distributed databases.
• Experience with financial services or other regulated industries.

Culture & Benefits

• Flexible hybrid working arrangement between home and the Bucharest office.
• Collaborative environment with fair and constructive feedback.
• Opportunity to build foundational technology used across ING’s global digital banking ecosystem.
• Work alongside more than 2,000 engineering, risk, and operations professionals in Romania.