Senior Java Backend Engineer - Scalable, Real-Time Systems

United States Digital Space LLC; Singapore; On-site; SGD 90,000 - 150,000; Full time

Job summary

United States Digital Space LLC in Singapore is seeking a strong Mid or Senior Java Engineer to shape and scale the backend of KaiKai Lock Screen and CMS, serving millions of users daily.

You will design, develop, and maintain backend services, build scalable data processing, contribute to architecture, ensure code quality, and collaborate with Product, Content, and Data teams to deliver impactful features.

Qualifications

• Proven experience in Java backend development.
• Skilled at building scalable, high-performance backend systems.
• Familiar with event-driven architectures using Kafka.
• Strong knowledge of relational databases and SQL.
• Ability to own projects and drive solutions.
• Excellent communication in Polish and English.

Responsibilities

• Design, develop, and maintain backend services for KaiKai Lock Screen and CMS.
• Build scalable systems for large-scale data processing and real-time content delivery.
• Contribute to architecture and system design improvements.
• Maintain high code quality through testing, code reviews, and engineering best practices.
• Work with distributed and event-driven systems to build scalable backend solutions.
• Improve system performance, reliability, and efficiency for a high-traffic product.
• Support integrations with external services and third-party systems.
• Collaborate closely with Product, Content, and Data teams to deliver meaningful features.
• Share knowledge and contribute to continuous team improvement.

Skills

Java backend

Scalable systems

Kafka event-driven

SQL databases

Ownership

Polish & English

High-traffic experience

Tools

Kafka

Job description

United States Digital Space LLC in Singapore is seeking a strong Mid or Senior Java Engineer to shape and scale the backend of KaiKai Lock Screen and CMS, serving millions of users daily.

You will design, develop, and maintain backend services, build scalable data processing, contribute to architecture, ensure code quality, and collaborate with Product, Content, and Data teams to deliver impactful features.