Junior Backend Developer
Synthorx
About us
At Sanofi, we chase the miracles of science to improve people’s lives. All our decisions are taken with our most important stakeholder in mind – the patients.
Having a rich history of innovation that dates back over 100 years, Sanofi more than ever stays true to its commitment to transform the practice of medicine by providing potentially life-changing treatments and the protection of life-saving vaccines to millions of people. This history includes the first treatments for many rare diseases and the establishment of standards of care in diabetes and cardiovascular disease. Sanofi’s commitment to public health has helped protect hundreds of millions of people from influenza every year for decades and pushed polio to the brink of eradication, while its scientific vision has led to breakthrough innovations in the treatment of inflammatory diseases.
~ 43.07Bn€ Net Sales FY23
~90 countries
~ 91K employees
~ 59 manufacturing sites
~ 20 R&D sites
Job Overview
We are looking for a motivated Junior Backend Developer with 4+ years of backend development experience, who is passionate about building scalable backend services using modern cloud-native technologies. In this role, you will work under the guidance of senior developers to develop backend services using Java Spring Boot (Java 17+), participate in large-scale system development, and gradually adopt LLM-powered coding workflows. This is an excellent opportunity to gain hands-on experience with distributed systems, Kubernetes, CI/CD automation, and Infrastructure as Code (IaC), while working in a bilingual (English/Chinese) engineering environment.
Key Responsibilities
Develop and maintain backend services using Java Spring Boot (Java 17+), following architectural patterns defined by senior developers.
Contribute to Spring Gateway configuration and learn to manage API routing and security rules.
Assist in implementing backend features by leveraging LLM tools (e.g., GitHub Copilot) for code generation.
Collaborate on data modeling, system modularization, and service orchestration following existing design standards.
Integrate and support services using Redis, Elasticsearch, and relational databases such as PostgreSQL.
Learn to deploy and troubleshoot applications in Kubernetes, using kubectl and Helm under team guidance.
Support the CI/CD workflow using GitHub Actions, ensuring smooth automated builds and deployments.
Help maintain Infrastructure as Code practices using tools like Terraform or similar, with mentoring from senior staff.
Work closely with frontend developers, QA engineers, and DevOps team members to ensure seamless backend integration.
Participate in Agile ceremonies including daily stand-ups, sprint planning, and retrospectives.
Required Skills & Qualifications
Technical Expertise
4+ years of experience in backend development, primarily using Java Spring Boot.
Familiarity with Spring MVC, Spring Data, and RESTful API development.
Exposure to Spring Gateway and interest in API gateway design and optimization.
Experience working with relational databases (e.g., PostgreSQL or MySQL) and basic knowledge of ORM frameworks (e.g., Hibernate).
Hands-on experience with Redis and basic Elasticsearch operations.
Exposure to Kubernetes, Docker, and microservice deployment concepts.
Familiarity with CI/CD tools such as GitHub Actions and build tools like Gradle or Maven.
Basic understanding of Terraform or Infrastructure as Code principles.
Interest in LLM-powered development and willingness to adopt tools like Copilot into daily workflow.
DevOps & CI/CD
Interest in LLM-powered development and willingness to adopt tools like Copilot into daily workflow.
LLM-Assisted Development
Initial experience with LLM tools such as GitHub Copilot; eager to adopt AI-assisted workflows into day-to-day development.
Ability to teach and guide team members in adopting LLM-assisted coding workflows to enhance efficiency.
Mindset & Practices
Strong willingness to learn from senior developers and adopt modern development practices.
Adheres to a “do not reinvent the wheel” philosophy—prefers reusing well-established libraries, frameworks, and solutions.
Attention to detail and commitment to writing clean, maintainable code.
Strong team spirit, communication skills, and accountability in collaborative environments.
Language Proficiency
Fluency in English (speaking and writing) for documentation and collaboration with global teams.
Comfortable working in Chinese for day-to-day interactions and local team collaboration.
Soft Skills
Strong problem-solving skills with a pragmatic approach to balancing innovation and practicality.
Strong communication and collaboration skills; able to work effectively with cross-functional team members.
Preferred Qualifications
4+ years of backend development experience
Experience with Java (Spring framework) or C# (.NET Core) is a plus.
Familiarity with monitoring tools such as Prometheus, ELK, or Grafana.
Experience with message queues (e.g., RabbitMQ, Kafka) or GraphQL is a bonus.
Exposure to Tencent Cloud, AWS, or other cloud platforms.
Interest in the healthcare or pharmaceutical industry.
Complementary Technologies
In addition to the core requirements, proficiency in the following technologies is highly desirable:
Gradle or Maven for build automation.
Git for version control and collaborative development.
RESTful APIs, with bonus points for experience in GraphQL.
Basic shell scripting or DevOps skills will be advantageous.
Pursue progress, discover extraordinary
Better is out there. Better medications, better outcomes, better science. But progress doesn’t happen without people – people from different backgrounds, in different locations, doing different roles, all united by one thing: a desire to make miracles happen. So, let’s be those people.
At Sanofi, we provide equal opportunities to all regardless of race, colour, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, ability or gender identity.
Watch our ALL IN video and check out our Diversity Equity and Inclusion actions at sanofi.com!