Senior Software Engineer

Sitero is an emerging leader in Clinical services and software solutions for the life sciences industry. We have experience and expertise in a diverse range of therapeutic areas and focus on innovative, technology-enabled solutions that allow our clients to focus on their core strengths. For early phase studies through Phase III clinical trials, our experienced team delivers high-touch services and technology to ensure the safety of all stakeholders across the clinical research community with an emphasis on ethics, compliance, and innovation.
Sitero is looking for a skilled Senior Software Engineer to primarily use Python to design, build, and maintain enterprise-grade features across our Life Sciences SaaS platform. You will work across the full technology stack — from crafting clean, responsive React frontends to building robust Python microservices — in a regulated environment that demands high code quality, security, and reliability.
As part of our Engineering team, you will collaborate closely with Product Management, QA, Dev Ops, and Clinical domain experts to deliver compliant, scalable software that supports clinical trials, pharmacovigilance, and patient safety workflows globally.

Job Title:

Senior Software Engineer

Location:

Mississauga, Ontario (Hybrid). 3x per week in office, 2x per week remote  Function:
Engineering

ESSENTIAL DUTIES AND RESPONSIBILITIES:

Design and develop full-stack features using Python/FastAPI or Django (backend) and React/Type Script (frontend)
Build and maintain RESTful APIs and GraphQL endpoints consumed by internal and external systems
Develop reusable, maintainable UI components and integrate them with backend services
Participate in architecture reviews and contribute to technical design decisions
Backend Engineering   Develop microservices following domain-driven design patterns and 12-factor app principles
Implement secure authentication and authorization using OAuth 2.0, OIDC, and Python security libraries
Optimize SQL/No

SQL queries, manage database migrations (Alembic), and design efficient data models
Integrate with third-party APIs, HL7/FHIR standards, and clinical data systems where applicable
Quality & Compliance   Write comprehensive unit, integration, and end-to-end tests (pytest, React Testing Library, Playwright/Cypress)
Adhere to 21 CFR Part 11, HIPAA, and GxP standards in all development activities
Support IQ/OQ/PQ validation activities and maintain traceability between requirements and code
Participate in code reviews, enforce coding standards, and contribute to static analysis (Sonar Qube, Ruff/Black)
Collaboration & Delivery   Work in Agile/Scrum sprints; contribute to sprint planning, grooming, and retrospectives
Partner with QA on test planning, defect triage, and release readiness
Document technical designs, API specifications (OpenAPI/Swagger), and runbooks
Mentor junior developers and support onboarding of new team members
Technology Stack  Category  Technologies  Backend  Python 3.10+, FastAPI, Django/Django REST Framework, SQL Alchemy, Celery, Pydantic
Frontend  React.js, Type Script, HTML5, CSS3/SCSS, Redux / Zustand, Vite/Webpack
Database  PostgreSQL, MySQL, MongoDB, Redis — query optimization & schema design
Cloud & Dev Ops  AWS (EC2, S3, RDS, Lambda) or Azure, Docker, Kubernetes, CI/CD pipelines
API & Integration  OpenAPI/Swagger, OAuth 2.0 / OIDC, Kafka/RabbitMQ, Microservices architecture
Testing  pytest, pytest-asyncio, React Testing Library, Playwright/Cypress, Sonar Qube, automated regression suites
Tooling  Git/Git Hub, JIRA, Poetry/pip, VS Code / PyCharm, Agile/Scrum
EDUCATION AND EXPERIENCE

REQUIRED:

Bachelor's or master’s degree in computer science, Engineering, or a related field
5–8 years of professional software development experience
Strong proficiency in Python 3.10+ and backend frameworks such as FastAPI or Django REST Framework
Solid frontend experience with React.js, Type Script, and modern CSS (SCSS/Tailwind)
Hands-on experience with relational databases (PostgreSQL or MySQL) and query optimization
Familiarity with containerization (Docker) and orchestration (Kubernetes)

Experience with cloud platforms — AWS or Azure — and CI/CD pipeline…