Full-Stack Software Engineer

Our Client is seeking a Senior Full-Stack Software Engineer (8+ years of experience) to design, develop, test, and maintain high-volume enterprise applications. Operating under a Hybrid work model (4 days per week in office) out of Waterloo, ON, this role leads the end-to-end software development lifecycle (SDLC), specializing in high-throughput Java / Spring Boot microservices, complex SQL Server database optimization, and user-centric front-end interfaces.

In this role, you will architect, build, and scale resilient enterprise software solutions from the database and API layer through to the user interface. Operating at a senior engineering tier, you will partner with cross-functional teams—including product owners, UX designers, and enterprise architects—to assess functional requirements, choose optimal technology stacks, and execute high-performance software architectures. A significant portion of this role centers on engineering high-volume REST APIs in Spring Boot, designing performant relational schemas in SQL Server, and tuning database performance through advanced indexing and query optimization.

Advantages
High-Throughput Engineering: Build mission-critical REST APIs and microservices designed to process high call volumes reliably.

Database Optimization Focus: Apply deep database expertise to architect relational schemas, optimize indexing strategies, and eliminate performance bottlenecks.

Architectural Influence: Lead high-level software architecture decisions, technology stack evaluations, and deployment strategies.

Modern Cloud & Container Ecosystem: Direct exposure to container platforms (Kubernetes, OpenShift, Docker), public clouds (GCP, Azure, AWS), and enterprise log analytics (ELK stack).

Responsibilities
1. Backend Architecture & High-Volume API Engineering
Design, build, test, and deploy resilient backend microservices and RESTful APIs using Java and Spring Boot, engineered for high call volume and low latency.

Apply advanced Object-Oriented Programming (OOP) principles, design patterns, and domain-driven architectures to write clean, maintainable code.

Evaluate application requirements to determine appropriate technology stacks, integration patterns, and deployment strategies.

Implement software security best practices, including user authentication, authorization, data encryption, and sensitive data anonymization.

2. Database Modeling & SQL Server Performance Tuning
Architect, model, and maintain scalable relational databases using Microsoft SQL Server.

Author complex SQL queries, stored procedures, and triggers while establishing advanced indexing and partitioning strategies.

Profile, diagnose, and optimize slow-running queries and database deadlocks to ensure consistent transactional throughput.

3. Full-Stack Development, Testing & DevOps
Develop and maintain responsive, intuitive front-end user interfaces using JavaScript, HTML, and modern web tooling.

Define and execute test automation strategies following Test-Driven Development (TDD), unit testing, and automated integration testing.

Collaborate within an Agile cadence (stand-ups, sprint planning, retrospectives) to deliver iterative software increments.

Support CI/CD deployment pipelines, containerized environments, and production observability.

Qualifications
Core Experience & Education
Education: Bachelor’s degree in Computer Science, Software Engineering, or a related technical discipline.

Software Development Tenure: 8+ years of hands-on professional software development experience (primarily in Java or C#).

Database Tenure: 8+ years of dedicated experience architecting, querying, and optimizing relational databases (SQL Server).

Technical Skillset Matrix
Java: Advanced proficiency writing enterprise Java application code with a deep understanding of OOP design principles.

Spring Boot: Demonstrated track record building high-volume REST APIs and microservices.

SQL Server: Proven expertise writing SQL queries, profiling execution plans, tuning slow queries, and designing relational indexing strategies.

Front-End Development: Practical hands-on experience building web interfaces using JavaScript, HTML, and CSS.

Preferred Qualifications (Nice to Have)
Hands-on experience with the ELK Stack (Elasticsearch and Logstash in particular) for log aggregation and search.

Containerization and orchestration experience with Docker, Kubernetes, or OpenShift.

Cloud deployment exposure across public cloud providers (GCP, Azure, or AWS).

Experience with Python for automation, scripting, or data pipelines.

Familiarity with embedded systems concepts, low-level debugging, or GDB.

Soft Skills & Professional Attributes

User-Centric Mindset: Empathetic approach to understanding customer pain points and translating them into practical features.

Analytical Problem Solver: Systematic approach to troubleshooting complex full-stack and database performance issues.

Cross-Functional Collaboration: Strong oral and written communication skills to articulate architecture decisions and technical tradeoffs to engineering leaders and product teams.

Summary
Ourclient in Waterloo, ON, is seeking a Senior Full-Stack Software Engineer (8+ years of experience) for a hybrid role requiring four days per week on-site.

Core Scope: Lead the end-to-end SDLC to architect, build, and scale high-volume, resilient enterprise applications across the entire stack, collaborating closely with product owners, UX designers, and architects.

Technical Focus:

Backend & APIs: Developing high-throughput microservices and REST APIs using Java and Spring Boot.

Database & Performance: Designing relational schemas and optimizing SQL Server database performance through query tuning and advanced indexing.

Frontend: Delivering responsive, user-centric front-end interfaces.

Randstad Canada is committed to fostering a workforce reflective of all peoples of Canada. As a result, we are committed to developing and implementing strategies to increase the equity, diversity and inclusion within the workplace by examining our internal policies, practices, and systems throughout the entire lifecycle of our workforce, including its recruitment, retention and advancement for all employees. In addition to our deep commitment to respecting human rights, we are dedicated to positive actions to affect change to ensure everyone has full participation in the workforce free from any barriers, systemic or otherwise, especially equity-seeking groups who are usually underrepresented in Canada's workforce, including those who identify as women or non-binary/gender non-conforming; Indigenous or Aboriginal Peoples; persons with disabilities (visible or invisible) and; members of visible minorities, racialized groups and the LGBTQ2+ community.

Randstad Canada is committed to creating and maintaining an inclusive and accessible workplace for all its candidates and employees by supporting their accessibility and accommodation needs throughout the employment lifecycle. We ask that all job applications please identify any accommodation requirements by sending an email to to ensure their ability to fully participate in the interview process.

This posting is for existing and upcoming vacancies.