Senior Java Developer - API Gateway @ING Hubs Romania

Preferred

• Experience building or operating API gateways at scale in a large enterprise or financial services environment; Knowledge of authentication & authorisation protocols: OAuth 2.0, OpenID Connect, JWT, SAML; Familiarity with observability tooling (Grafana, Prometheus, ELK) and SRE practices (SLOs, error budgets, on-call); Experience with high-availability and disaster recovery patterns across multi-data center setups.

This is critical infrastructure

every digital interaction with ING — mobile banking, web applications, third-party integrations, and internal tools — flows through the API Gateway. Your Day-to-Day As a Senior Software Engineer on the API Gateway team you will: Design, build, and maintain the gateway platform components — including configuration controllers, domain circuit breakers, and routing services — that power ING's inbound and outbound API traffic across internet and intranet facing domains; Develop and extend NGINX-based gateway configurations and custom modules to support Touchpoint API Gateway, Integration Gateway, Outbound Gateway, and front-end hosting use cases; Automate operations by building tooling around the automation framework for resource management, configuration deployment, and release train orchestration (production deploys twice per week); Ensure reliability and availability of a globally critical service, implementing resilience patterns such as circuit breakers, canary deployments, and DDoS mitigation across multiple data centers; Collaborate across squads with platform engineers, SREs, security teams, and consuming product teams to onboard new domains, troubleshoot issues, and define gateway standards; Handle incident management including P1/P2 priority incidents, emergency production changes, and post mortem analysis; Contribute to the CI/CD pipeline , ensuring automated testing, configuration validation, and safe rollout of changes across dev, test, acceptance and production environments.

Technology Stack Languages

Java, Python, Bash, Rego; Infrastructure: ING Private Cloud, OpenShift, Linux; Configuration & Orchestration: Automation Framework, Azure DevOps CI/CD; Observability: Grafana, Prometheus, ELK stack; Security: OAuth 2.0, JWT, ING Authentication solution, Zero Trust principles. What You'll Bring to the Team Required 5+ years of hands-on software engineering experience, with a strong track record in building and operating distributed systems or platform/infrastructure products; Proficiency in Java . Experience with Go, Python, C, Bash is a plus. Familiarity with containerisation and orchestration (Kubernetes, Docker) and CI/CD pipelines; Knowledge of NGINX (configuration, modules, reverse proxy patterns) or comparable API gateway / proxy technologies (e.g., Envoy, HAProxy, Kong); Good understanding of networking fundamentals : HTTP/HTTPS, TLS/mTLS, DNS, load balancing, firewalls, and DMZ architectures; Strong debugging and incident response skills — comfortable operating under pressure during P1/P2 incidents; Excellent communication and collaboration skills; ability to work effectively in a cross-functional, globally distributed team.

Preferred

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