Senior Software Developer - API

We are seeking an experienced Senior Software Developer - API with 8+ years of expertise to drive the design, development, and deployment of scalable, high-performance API solutions and microservices. In this role, you will take technical ownership over converting functional specifications into secure, decoupled, and event-driven applications. Operating across Java, Spring Boot, and cloud environments, you will architect RESTful web services, engineer message-oriented integration pathways, design relational database schemas, and enforce robust security protocols to support critical enterprise platforms. Location: Toronto, ON (Fully Onsite – 5 days/week required) Duration: 12-month contract. Advantages Enterprise API Ownership: Command full design and execution authority over modern, decoupled Spring Boot microservices. Cloud & Event-Driven Stack: Architect solutions leveraging Azure Services, Azure Event Hubs, and containerized Kubernetes environments. Deep Integration Exposure: Solve complex data transformation and messaging challenges using advanced enterprise integration patterns. Collaborative Onsite Culture: Drive high-impact engineering execution alongside an experienced development squad in a 5-day onsite setting. Responsibilities REST API & Integration Engineering: Design, build, consume, and document clean, secure RESTful APIs and integration solutions using Java, Spring Boot, and Spring Integration. Microservices & Event-Driven Architecture: Architect modular, decoupled microservices and event-driven architectures using Azure Services, Azure Service Bus, and messaging queues for asynchronous data processing. Data Transformation & Mapping: Map, normalize, and transform complex data structures across JSON, XML, and CSV formats utilizing Spring Integration tools, XSLT, and XPath. Database Design & Query Optimization: Design efficient relational database schemas and write complex SQL queries using SQL Server or Oracle databases. Security & Authentication Governance: Secure API endpoints and communication pathways implementing OAuth2, JWT, SAML, input validation, and OWASP security standards. Testing & Automated Validation: Develop comprehensive automated unit and API test suites using JUnit, Mockito, or Test Containers to ensure code reliability and prevent regressions. Containerization & CI/CD Deployment: Package applications using Docker, docker-compose, and Kubernetes manifests for smooth cloud deployment and continuous delivery pipelines. Observability & Monitoring: Integrate operational logging and telemetry frameworks (ELK stack, Splunk, Prometheus, Grafana) to ensure real-time system visibility. Technical Mentorship & Code Reviews: Conduct regular code reviews, enforce design best practices, and mentor junior developers on the team. Operational & On-Call Support: Assist with troubleshooting production issues, perform root-cause debugging, and participate in technical support rotas. Qualifications REST API & Integration Seniority: Extensive experience designing, building, consuming, and documenting REST APIs and integration solutions using Spring Integration (Strictly Required). Microservices & Messaging Expertise: In-depth knowledge of microservice architecture and hands-on experience building scalable systems with Azure Services, message queues, event-driven architecture, and asynchronous multi-threading (Strictly Required). Relational Database Command: Strong SQL proficiency and hands-on experience working with relational databases such as SQL Server or Oracle (Strictly Required). Security & Token Protocols: Knowledge of security integration using OAuth2, JWT, SAML, and related authentication and authorization technologies (Strictly Required). Data Transformation & Formats: Proven capability handling data transformation, mapping, and normalization across JSON, XML, and CSV formats within a Spring Integration framework. Core Java Ecosystem Depth: 8+ years of hands-on software development exp