Topicus Vietnam

Overview of job

About the Project

We’re growing a lending self-service portal into a complete financial product platform (loans, savings, investments). This means:

• Building reusable component libraries that let the team ship features faster while maintaining consistency across web and mobile
• Building integrations with external systems (KYC/AML providers, payment processors, core banking) that are resilient, secure, and maintainable
• Architecting for scale and security in a regulated financial environment where downtime and data breaches aren’t options.

You’ll work with a modern stack (Java 21, Jakarta EE 11, MongoDB, Keycloak) deployed on OpenShift, but we value pragmatism over dogma. If you have a better approach, we want to hear it.

What you will accomplish

Your first-year goals:

• Working with the team to add mobile app capability to our self-service portal - building the backend APIs and infrastructure that enable Angular web apps to run as native iOS and Android applications
• ​Integrated with external systems that allow users to manage their savings products - connecting payment processors, core banking systems, and third-party services into a seamless experience.

Technical Foundations You’ll Use

• Backend: Java 21, Jakarta EE 11 (JAX-RS/RESTEasy), WildFly 36 Java
• Data: MongoDB 4.x with GridFS for document storage
• Security: OAuth2/OIDC with Keycloak
• Infrastructure: Docker, Kubernetes/OpenShift, CI/CD via GitHub Actions and Jenkins
• Quality: JUnit, Mockito, WireMock, SonarQube, automated testing as standard practice.

• Attractive salary (annual salary review)
• Fixed 13th-month salary and performance bonus
• Full salary during probation and full coverage of social insurance
• Hybrid working model and good work-life balance
• Premium healthcare (with annual health check-up)
• 16 days of annual leave per year
• 5 paid sick leave days
• Dynamic and international English-speaking working environment
• Regular gatherings (happy hour, bimonthly dinner, social events, etc.)
• Annual company trip
• Fully stocked pantry with coffee and snacks
• Budget for team activities
• Supportive and diverse work environment that promotes continuous learning
• Opportunity for traveling and training in the Netherlands.

What you must excel at

You must be exceptionally strong in the following areas:

• External system integration - You’ve built systems that talk to multiple third-party APIs (payments, identity verification, core banking) and know how to handle failures gracefully, manage API versioning, and keep integrations from becoming a maintenance nightmare
• Security-first API design - You understand OAuth2/OIDC flows, design REST APIs with OpenAPI specs that frontend teams love, and think about authorization and compliance from day one— not as an afterthought.

What we are looking for
You likely have:

• 5+ years building production Java systems with Jakarta EE or Java EE Real experience integrating with external APIs at scale (not just one REST endpoint)
• Hands-on work with OAuth2/OIDC authentication and API security
• Experience with application servers (WildFly, JBoss, Payara, or similar)
• Comfort with NoSQL databases (MongoDB preferred, but Cassandra/Couchbase experience translates)
• Strong testing habits—you write tests because you’ve been burned before.

You’ll thrive here if:

• You care about API design—you think about the developer experience on the consuming side
• You’ve worked in regulated industries (finance, healthcare) and understand compliance constraints
• You enjoy modern tooling (CI/CD, containerization, GitOps) but know when to keep it simple
• You communicate clearly in English with distributed teams (Vietnam, Europe).

Bonus points for:

• Financial services domain knowledge (lending, savings, payments)
• Keycloak identity management experience
• Document management systems with e-signatures
• Mobile backend experience (understanding what mobile apps need from APIs).