Senior Backend Developer (Java / Spring / AWS)

Job Requirements At Quest Global, it’s not just what we do but how and why we do it that makes us different. With over 25 years as an engineering services provider, we believe in the power of doing things differently to make the impossible possible. Our people are driven by the desire to make the world a better place—to make a positive difference that contributes to a brighter future. We bring together technologies and industries, alongside the contributions of diverse individuals who are empowered by an intentional workplace culture, to solve problems better and faster.

Job Title: Senior Backend Developer — Java, Reactive Spring, AWS

Experience: 6+ years of hands-on backend engineering, including 3+ years building cloud-native, event-driven services on AWS.

Job Summary We are seeking an experienced Senior Backend Developer to build and scale the services behind our Dynamic Service Options (DSO) platform. You will work across two Java + Spring Boot (WebFlux) codebases:

• an authoring backend — the data-production side, where machine parts and service data are ingested from a cloud data warehouse, validated, enriched by a service-option engine, and published as datasets
• a delivery backend — the consumption side, which receives published datasets, applies dataset-level permissions, and serves the user-facing APIs behind the embeddable Dynamic Service Options experience

Both are fully reactive, event-driven systems on R2DBC/PostgreSQL, AWS Lambda, SQS and ECS Fargate, sharing a multi-module Gradle structure, OpenAPI-first APIs, Flyway-managed schemas, OpenTelemetry tracing and CloudFormation-driven deployments.

The ideal candidate is fluent in non-blocking reactive programming with Project Reactor, comfortable owning a feature end-to-end (API → async job → database → infrastructure → dashboard), and holds a high bar for testing, observability and secure-by-default design.

Key Responsibilities

• Design, build and maintain reactive REST APIs using Spring Boot WebFlux, returning Mono/Flux end-to-end with no blocking calls anywhere in the request path.
• Develop and evolve event-driven background jobs running on AWS Lambda, triggered by SQS FIFO queues and EventBridge cron schedules, using a mediator/command-handler pattern with explicit concurrency control, retry policies and dead-letter queue handling.
• Model and query data in PostgreSQL (Aurora Serverless) using Spring Data R2DBC repositories and a type-safe jOOQ DSL for dynamic queries; leverage advanced Postgres features such as JSONB, ltree hierarchies, partitioning and appropriate GIN/GIST indexing.
• Author and review Flyway migrations (versioned and repeatable), keeping schema changes backward-compatible and validated in CI.
• Maintain a clean multi-module Gradle architecture — shared library, API service and Lambda worker — placing code in the correct module and avoiding cross-layer leakage.
• Design OpenAPI-first APIs: generated specs, standardized response envelopes and error models, spec linting in the pipeline, and consistent HTTP semantics
• Integrate with external systems — Snowflake (REST API with JWT key-pair auth and long-running query polling), internal product/entitlement services, and AWS services (S3, Secrets Manager, DynamoDB) via async SDK clients.
• Implement caching and performance strategies (Caffeine in-memory/Redis caches with TTLs, query tuning, parallel composition with Mono.zip) for high-volume ingestion and reporting workloads.
• Instrument services with OpenTelemetry / AWS Distro for OpenTelemetry (ADOT): custom spans, trace-context propagation across HTTP and SQS boundaries, structured logging, and RED metrics surfaced in CloudWatch Application Signals, X-Ray and Grafana dashboards.
• Write unit and integration tests with JUnit 5, Mockito and Reactor StepVerifier; keep coverage and quality gates green in SonarQube.
• Contribute to CI/CD: GitHub Actions build/test/scan workflows, multi-stage Docker builds, ECR image publishing, Lambda artifact packaging, and CloudFormation deployments across dev/QA/UAT/prod.
• Apply secure-by-default practices: OAuth2 resource-server token validation, role/entitlement-based authorization filters, least-privilege IAM, secrets in AWS Secrets Manager (never in code), and input validation at every boundary.
• Participate in code reviews, uphold documented coding standards, and mentor mid-level engineers on reactive patterns and cloud design.

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