Overview

About Certara is a growing company that provides a dynamic and exciting place to work. Our purpose is to assist in accelerating the development of meaningful medicines that make an impact on our society and the people that need them most. Innovation and creativity are highly valued, and everyone is given the opportunity for training and continuous development. Our portfolio spans the discovery, preclinical, clinical and post‑marketing phases of drug development, working with 1,200 commercial companies, 250 academic institutions, and numerous regulatory agencies.

As a Senior Software Developer at Certara, you will lead the design, development, and optimization of cloud‑native, scalable, web applications, APIs and services. Collaborating with developers, IT, DevOps, and science teams, you’ll drive technical solutions, mentor others, and ensure high‑quality deliverables that support our business operations and customer needs in a dynamic, forward‑thinking environment.

This role is remote in the UK, but occasional attendance in the Sheffield office is required.

Responsibilities

• Lead the design, development, testing, and deployment of cloud‑native scalable, high‑performance solutions and platforms, including web applications, APIs, services, databases, event busses and other infrastructure.
• Provide collaborative expertise and consultancy on distributed event‑driven cloud architecture good practices.
• Partner with internal stakeholders to define, analyse, and architect technical solutions that meet complex requirements.
• Diagnose and resolve advanced issues related to functionality, performance, scalability, and user experience.
• Collaborate with the DevOps team to design and optimize deployment pipelines and maintain robust cloud‑hosted solutions.
• Oversee the integration of APIs and third‑party services, ensuring seamless functionality and performance.
• Drive the development and maintenance of automated tests for APIs to guarantee reliability and efficiency.
• Provide expert technical support and mentorship to internal teams, customers, and junior developers.
• Enhance and maintain existing applications, implementing improvements in performance, reliability, and scalability.
• Enforce security best practices and ensure applications meet stringent protection standards.
• Proactively stay ahead of development trends, frameworks, and emerging technologies, recommending innovative solutions.

Qualifications

Essential

• Bachelor’s degree in Computer Science or a related degree or equivalent professional experience
• 5+ years of proficiency in .NET C# and ASP.NET with a strong track record of delivering complex web solutions
• Proven experience of designing and building distributed event‑driven cloud architectures on AWS or Azure, using container orchestration (e.g. Kubernetes), and/or cloud native serverless tools (e.g. AWS Lambda, SQS/SNS, or Azure Functions, Service Bus, Event Grid)
• Proven experience with SQL databases (e.g. SQL Server, PostgreSQL, SQLite) and/or No SQL databases (e.g. MongoDB, AWS DynamoDB, Azure Cosmos)
• Proven experience with .NET ORMs (e.g. Entity Framework, Dapper)
• Advanced understanding of good practice API development, integration, and testing (e.g. RESTful services, GraphQL).
• Advanced understanding of security best practices, performance optimization, and scalability techniques in a SaaS or public cloud facing system.
• Exceptional problem‑solving skills, with an ability to weigh up pros and cons of architectural decisions, and meticulous attention to detail.
• Excellent communication and leadership skills, with a proven ability to thrive in a collaborative team setting.
• Significant experience with version control systems such as Git.
• Strong expertise in writing and maintaining automated tests (e.g., unit, integration, or component tests using NUnit, xUnit, Jest, or Jasmine).

Desirable

• Experience with both front‑end (e.g. React, TypeScript) and back‑end (.NET C#, ASP.NET) development, especially related to API consumption good practices such as schema validation, or event‑driven architectures (e.g. webhooks).
• Proficiency in modern web technologies (e.g. JavaScript, TypeScript, HTML, CSS).
• In‑depth understanding of CI/CD pipelines and DevOps practices, particularly in Azure.
• Extensive experience with automated testing frameworks for APIs (e.g., Postman, NUnit).
• Expertise with external dependency mocking tools (e.g., TestContainers, Wiremock).
• Prior experience mentoring developers or leading technical initiatives.

Certara bases all employment‑related decision on merit, taking into consideration qualifications, skills, achievement, and performance. We treat all applicants and employees without regard to personal characteristics such as race, color, ethnicity, religion, sex, sexual orientation, age, nationality, marital status, pregnancy, physical or mental condition, genetic information, military service, or other characteristic protected by law.