Senior Software Engineer

About the Technology Organization 

Technology at Lilly builds and maintains capabilities using pioneering technologies like most prominent tech companies. What differentiates Technology at Lilly is that we create new possibilities through tech to advance our purpose – creating medicines that make life better for people around the world, like data driven drug discovery and connected clinical trials. We hire the best technology professionals from a variety of backgrounds, so they can bring an assortment of knowledge, skills, and diverse thinking to deliver solutions in every area of our business. 

About the Business Function 

The Software Product Engineering (SPE) team is a specialised engineering group that delivers strategic solutions and differentiated capabilities. We take a forward-thinking approach, focusing on an enterprise platform and product mindset, ensuring that the solutions we build can be leveraged across Technology teams for broader impact and efficiency. 

Job Title: Senior Software Engineer  

Role Summary 

As a Senior Backend Software Engineer, you will design, develop, and maintain scalable, high-performance server-side applications and APIs. You will collaborate with cross-functional teams, mentor junior engineers, and drive technical excellence in cloud-native, secure, and maintainable solutions. 

What You’ll Be Doing 

• Develop and maintain scalable, high-performance server-side applications using Node.js and Express.js. 

• Build and maintain RESTful APIs to support frontend systems and external service integrations. 

• Integrate with PostgreSQL databases using ORM tools such as Sequelize and Knex.js. 

• Design and implement performant and reliable systems by applying appropriate caching strategies and integrating distributed components such as Redis, CDNs, and message queues. 

• Handle file uploads and processing using tools like Multer, ExcelJS, and CSV Parse. 

• Ensure secure authentication using frameworks such as Azure MSAL Node, JWT, and express-session. 

• Optimise backend services for scalability, performance, and security. 

• Collaborate with frontend developers to ensure smooth integration and API consumption. 

• Build and maintain CI/CD pipelines using GitHub Actions and Docker. 

• Manage infrastructure using AWS ECS Fargate, S3, RDS PostgreSQL, Secrets Manager, and CloudFormation. 

• Collaborate with frontend teams using React.js and Material-UI. 

• Use build tools such as Webpack, Babel, Vite, and ESLint. 

• Write and maintain tests using Jest, React Testing Library, Cypress, and Playwright. 

• Participate in code reviews, contributing backend expertise and ensuring best practices are followed. 

• Implement security best practices using Helmet, CORS, SSL/TLS, and rate limiting. 

• Ensure all backend solutions comply with healthcare regulations (e.g., HIPAA, GDPR) and Lilly’s internal compliance standards. 

• Maintain rigorous data privacy and protection protocols throughout the software development lifecycle. 

• Leverage AI tools like GitHub Copilot to accelerate development workflows, improve code quality, and reduce boilerplate. 

• Encourage and mentor team members on responsible and secure use of AI in the software development lifecycle. 

How You Will Succeed 

• Proven expertise in designing and implementing scalable backend architectures using microservices, serverless, and event-driven patterns, grounded in SOLID principles, design patterns, and clean code practices. 

• Demonstrated ability to apply strong system design principles to build modular, robust, and maintainable backend solutions that support long-term scalability and reliability. 

• Hands-on experience with security best practices and compliance in highly regulated environments. 

• Skilled in code review, refactoring, and continuous improvement of backend systems to ensure long-term maintainability and performance. 

• Effective verbal and written communication skills. 

• Ability to work collaboratively across frontend, DevOps, and product teams. 

What You Should Bring 

• Proven experience in backend development using Node.js and Express.js. 

• Strong understanding of API design (REST & GraphQL) and real-time data flow. 

• Proficiency in PostgreSQL and ORM tools (Sequelize, Knex.js). 

• Experience with cloud infrastructure (preferably AWS), CI/CD pipelines, and containerisation (Docker). 

• Bachelor’s degree in computer science, Computer Engineering, or a related field. 

• 5-8 years of professional software development experience. 

Preferred Qualifications 

• Knowledge of accessibility best practices and WCAG standards. 

• Familiarity with Core Web Vitals and frontend performance optimisation techniques. 

• Hands-on experience with responsive design and cross-browser compatibility. 

• Expertise with cloud platforms (preferably AWS is mandatory), including hands-on experience with containerisation technologies such as Docker and AWS ECS/ECR.  

• Having AWS and Kubernetes certifications is a significant advantage and will be highly valued for this role. 

• Experience in regulated industries (e.g., Life Sciences) is a bonus but not required. 

• Contributions to open-source projects or developer communities.