{"id":1254043,"url":"https://alion.io/job/optimum-infosystem-senior-backend-java-developer","title":"Senior Backend Java Developer","company":{"id":3800114,"name":"Optimum Solutions","domain":"theoptimum.net","url":"https://alion.io/company/optimum-infosystem","size_band":"1001-5000","is_staffing_agency":true,"employer_type":"agency","is_intermediary":false,"listed_via":null,"ats_vendor":null,"truth_index":null},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":"full_time","work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Singapore"],"countries":["SG"],"hiring_countries":[],"hiring_countries_total":0,"salary":{"min":6000,"max":8000,"currency":"SGD","period":"month","gross":true,"usd_annual":75168},"salary_estimate":null,"experience_years_min":5,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Apache Kafka","optional":false},{"name":"Dependency Injection","optional":false},{"name":"Flyway","optional":false},{"name":"Gradle","optional":false},{"name":"Hibernate","optional":false},{"name":"Java","optional":false},{"name":"JUnit","optional":false},{"name":"Liquibase","optional":false},{"name":"Logback","optional":false},{"name":"Maven","optional":false},{"name":"Mockito","optional":false},{"name":"MySQL","optional":false},{"name":"Oracle","optional":false},{"name":"PostgreSQL","optional":false},{"name":"RabbitMQ","optional":false},{"name":"Redis","optional":false},{"name":"Rest API","optional":false},{"name":"SLF4J","optional":false},{"name":"Spring Boot","optional":false},{"name":"Spring Data JPA","optional":false},{"name":"Spring MVC","optional":false},{"name":"SQL","optional":false},{"name":"Swagger","optional":false},{"name":"CI/CD","optional":true},{"name":"Docker","optional":true},{"name":"Kotlin","optional":true}],"status":"live","first_seen_at":"2026-09-20T00:00:00Z","employer_posted_date":null,"last_verified_at":"2026-09-20T00:00:00Z","board_verified":false,"closed_at":null,"days_open":7,"trust":{"level":"not_scored","repost_count":null,"flags":[],"days_open":7},"description":"Position Overview\nWe are seeking an experienced Backend Java Developer with strong core Java capabilities and a deep focus on API design and backend architecture. In this role, you will design, build, and maintain high-throughput, secure RESTful APIs and enterprise backend components. You will focus on writing scalable code, optimizing multi-database interactions, mastering asynchronous execution, and driving sound object-oriented and functional programming practices across the stack.\nKey Responsibilities\nDesign, build, and maintain RESTful APIs and backend services using Java (11+) and the Spring / Spring Boot framework.\nImplement clean architectural patterns, object-oriented design principles (SOLID), and reusable software modules.\nAuthor standard OpenAPI/Swagger documentation for REST endpoints and internal contracts.\nLeverage Java concurrency utilities, multithreading frameworks, and asynchronous programming patterns to ensure efficient application performance.\nDiagnose, debug, and resolve memory leaks, thread contention, and garbage collection bottleneck issues using Java profiling tools.\nDesign and optimize relational (PostgreSQL, MySQL, Oracle) and NoSQL database schemas.\nManage data persistence and transactional boundaries using Spring Data JPA / Hibernate.\nWrite tuned SQL queries, establish effective database indexing, and configure connection pooling and caching strategies (e.g., Redis).\nImplement standard API security mechanisms (OAuth2, JWT authentication, authorization, and data sanitization).\nBuild structured logging, health checks, and application metrics using standard logging frameworks (Logback, SLF4J).\nWrite clean, maintainable, modular, and unit-tested code using JUnit and Mockito.\nParticipate in code reviews, technical architecture reviews, and maintain test coverage across applications.\nRequired Technical Qualifications\n5+ years of hands-on software development experience using Java 11/17+ with deep knowledge of Collections, Streams API, Multithreading/Concurrency, Memory Model, and Exception Handling.\nStrong expertise in Spring Boot, Spring Core, Spring MVC, and dependency injection paradigms.\nDeep understanding of RESTful architectural styles, HTTP status codes, JSON payload processing, custom middleware, and error-handling patterns.\nAdvanced proficiency in Spring Data JPA / Hibernate, multi-datasource routing, raw SQL query tuning, and database migration tooling (Flyway/Liquibase).\nPractical experience with message brokers and event streaming architectures using Kafka or RabbitMQ.\nSolid grasp of Design Patterns (Factory, Builder, Singleton, Strategy), TDD/unit testing principles (JUnit 5, Mockito), and build tools (Maven / Gradle).\nPreferred Qualifications\nUnderstanding of containerization basics (Docker) and modern CI/CD deployment workflows.\nFamiliarity with microservice resiliency concepts (Rate Limiting, Circuit Breakers, Retry policies).\nExperience with caching layers and distributed system synchronisation.\nSkills\nMessage Broker, Performance Profiling, RESTful API, Mockito, Technical Deployment, API Documentation, Asynchronous Programming, Java Web Services, Spring MVC, RESTful architecture, Spring Boot, Core Java, Spring Data, Rest Apis, Microservice, Advanced Java, Java, Object-Oriented Design, Logical Database Design","description_format":"text","description_chars":3309,"description_truncated":false,"requirements":{"experience_years_min":5,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":[],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["IT Consulting & Digital Transformation","IT Resellers & VARs"],"lifecycle":[{"event":"open","at":"2026-09-25T17:56:20Z"}],"liveness":{"score":83,"band":"hot","label":"Hiring now","p_open":1,"p_active":0.834,"p_room":1,"age_days":6,"expected_fill_days":31,"reasons":["seen:6","win:early"],"computed_at":"2026-09-26T05:45:00Z"},"pay":{"stated_usd_annual":75168,"is_top_pay":false},"html_url":"https://alion.io/job/optimum-infosystem-senior-backend-java-developer","json_url":"https://alion.io/job/optimum-infosystem-senior-backend-java-developer.json","meta":{"generated_at":"2026-09-27T03:59:36Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","usage":{"tier":"crawler","counted_by":"address","units_charged":1,"used_today":3733,"day_limit":5000,"remaining_today":1267,"minute_limit":60,"resets_at":"2026-09-28T00:00:00Z"}}}