Principal Software Engineer

About the Technology Organizationu00A0

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 u2013 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.u00A0

About the Business Functionu00A0

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.u00A0

Job Title: Principal Software Engineeru00A0u00A0

Role Summaryu00A0

As a Principal Software Engineer, you will lead the design, development, and delivery of business-critical applications across both frontend and backend systems. You will set engineering standards, mentor junior engineers, and drive technical excellence in cloud-native, scalable, and maintainable solutions. Your work will directly impact the reliability, performance, and value of our software products.u00A0

What Youu2019ll Be Doingu00A0

• Develop and contribute to frontend and backend frameworks supporting business-critical applications using JavaScript frameworks like ReactJS and Node.js.u00A0

• Design and build scalable, reusable, and maintainable backend services and APIs with Node.js, Express.js, PostgreSQL, and cloud-native patterns.u00A0

• Replace commercial off-the-shelf (COTS) systems with modern, in-house scalable solutions leveraging AWS (ECS Fargate, Lambda, S3, RDS, CloudFormation, CloudWatch) and containerisation (Docker).u00A0

• Develop user-facing interfaces using React (Material-UI, Bootstrap, React Router, Redux Toolkit, Emotion, Next.js) with a focus on performance, accessibility, and Core Web Vitals.u00A0

• Coach and mentor junior engineers and help raise the overall technical bar.u00A0

• Define and maintain engineering standards, including CI/CD (GitHub Actions, Jenkins, AWS CodeBuild) and code quality practices (ESLint, Prettier, Husky, lint-staged).u00A0

• Collaborate across teams to deliver impactful features with measurable value.u00A0

• Leverage AI tools like GitHub Copilot to accelerate development workflows, improve code quality, and reduce boilerplate.u00A0

• Lead the authoring of technical documents, including high-level design documents, architectural blueprints, technical standards, and best practice guidelines to drive technical excellence and cross-team alignment.u00A0

• Demonstrate proficiency in prompt engineering to effectively guide AI tools in generating optimal and context-aware code solutions.u00A0

• Use AI-assisted pair programming to support rapid prototyping, test case generation, and debugging.u00A0

• Encourage and mentor team members on responsible and secure use of AI in the software development lifecycle.u00A0

How You Will Succeedu00A0

• Design and implement robust APIs (RESTful) and microservices using Node.js and frameworks like Express.js or Koa.js.u00A0

• Build and manage scalable backend services with fault-tolerance, performance, and security in mind.u00A0

• Integrate with cloud platforms (AWS, GCP, or Azure) and manage infrastructure with CI/CD tools like GitHub Actions or Jenkins.u00A0

• Work with databases such as MongoDB and PostgreSQL to store and retrieve structured and unstructured data efficiently.u00A0

• Build responsive and accessible UIs using React, with supporting libraries such as Material-UI, Bootstrap, React Router, Redux Toolkit, Emotion, Next.js.u00A0

• Implement modern UI development practices, including component-based design and state management (Redux, Context API).u00A0

• Collaborate with designers and UX teams to implement pixel-perfect interfaces.u00A0

• Optimise front-end applications for performance and Core Web Vitals.u00A0

• Apply accessibility best practices and WCAG 2.2 standards.u00A0

• Lead code reviews, guide junior engineers, and build production-grade software.u00A0

• Contribute to open-source projects or lead technical discussions and architecture reviews.u00A0

What You Should Bringu00A0

• Strong proficiency in React.js and supporting libraries (Material-UI, Bootstrap, Redux Toolkit, React Router, Emotion, Next.js).u00A0

• Solid understanding of JavaScript (ES6+), TypeScript (4.xu20135.x), HTML5, and CSS3/SCSS/Sass.u00A0

• Proficient in backend development with Node.js (20.x+), Express.js (4.17.x+), Feathers.js.u00A0

• Experience with RESTful and GraphQL APIs, microservices architecture, and real-time communication (e.g., WebSockets).u00A0

• Practical experience with AWS (ECS Fargate, Lambda, S3, RDS, CloudFormation, CloudWatch), and containerisation (Docker).u00A0

• Having AWS and Kubernetes certifications is a significant advantage and will be highly valued for this role.u00A0

• Familiarity with state management tools (Redux, Context API).u00A0

• Strong testing experience using tools like Jest, React Testing Library, Cypress, Playwright.u00A0

• Comfortable with frontend build tools like Webpack (4.x/5.x), Vite, Babel (7.x), Gulp, NPM, and linters like ESLint, Prettier, Husky, lint-staged.u00A0

• Experience working with CI/CD pipelines, source control (Git), and modern DevOps workflows.u00A0

• Exposure to domain-driven design (DDD), serverless architecture, or event-driven systems.u00A0

• Knowledge of accessibility best practices and WCAG 2.2 standards.u00A0

• Experience in regulated industries (e.g., Life Sciences) is a bonus but not required.u00A0

Basic Qualifications and Experience Requirementu00A0

• Bachelor's degree in computer science, Computer Engineering, or a related technical field.u00A0

• 8+ years of hands-on software development experience across frontend and backend systems.u00A0

• Demonstrated ability to lead code reviews, guide junior engineers, and build production-grade software.u00A0

• Strong foundation in computer science fundamentals, software architecture, and cloud-native patterns.u00A0

• Effective verbal and written communication skills.u00A0

• Ability to work collaboratively across backend, frontend, DevOps, and product teams.u00A0

• A high degree of intellectual curiosity and commitment to continuous learning.u00A0

Additional Skills/Preferencesu00A0

• Familiarity with Core Web Vitals and frontend performance optimisation techniques.u00A0

• Experience with component-driven development using a design system (e.g., Material UI, Ant Design).u00A0

• Contributions to open-source projects or experience leading technical discussions and architecture reviews.u00A0

• Experience in regulated industries (e.g., Life Sciences) is a bonus but not required.u00A0