Senior Python Engineer

About Certara

Certara accelerates the potential of bringing medicines to market and to patients using biosimulation software, technology, and services to transform traditional drug discovery and development. Our clients include more than 2,400 biopharmaceutical companies, academic institutions, and regulatory agencies across 70 countries.

Our goal is to enable the life sciences industry’s use of data, modeling, and analytics to make better decisions across the various phases of discovery and drug development. Our software and scientists incorporate modern advances in scientific understanding, drug development experience, data analysis, and AI resulting in significant opportunities to decrease the cost and increase the probability of success for new drug approval and commercialization.

Certara is seeking a Senior Python Engineer to join the team behind Certara IQ, our quantitative systems pharmacology (QSP) modeling and simulation platform. This is a software engineering role with a strong infrastructure component. You will write Python most days: backend services built on FastAPI, our custom job scheduler, and the internal tooling that keeps the platform running. You will also own real infrastructure work on AWS using infrastructure-as-code.
We are looking for an engineer who is fluent in Python first, and who applies that fluency to infrastructure, automation, and reliability. If you are comfortable reading an unfamiliar FastAPI codebase, reasoning about decorators, generators, context managers, and dependency injection, and you also enjoy cloud architecture, this role is for you.

• Design, develop, and maintain Python backend services and internal tools, including our FastAPI services and custom job scheduler.

• Write clean, well-tested, idiomatic Python, and review the Python code of your teammates.

• Diagnose and fix performance, memory, and reliability issues across the API and data layers.

• Enhance and extend our AWS infrastructure running on ECS, Aurora Postgres, and related cloud services.

• Create, maintain, and improve CI/CD pipelines using CircleCI.

• Contribute to observability, monitoring, logging, and tracing, including Sentry and Elastic.

• Implement cloud security best practices and contribute to compliance-related engineering tasks.

• Collaborate with the DevOps engineer who leads the infrastructure domain to ensure reliability, security, and scalability across environments.

• Work with engineers across a seven-person team to support smooth development workflows, infrastructure upgrades, and upcoming new platform features.

• Strong, hands-on Python development experience.
• You are fluent with the language itself: decorators, generators, context managers, typing, and async code.
• Experience building and operating production web services, ideally with FastAPI or a similar Python framework.
• Strong experience with SQL and relational databases (Postgres preferred), including query performance.
• Strong experience with AWS and Docker.
• Experience with Terraform or another infrastructure-as-code framework.
• Experience running and debugging production systems in a cloud environment.
• We assess Python skills in depth during the hiring process. You should be comfortable reading, explaining, and improving real backend code.

Nice-to-Have:

• Kubernetes
• Sentry
• Elastic
• CircleCI
• AWS Lambda

What we offer 

• Hybrid way of working (8 days/month home office) 
• Private health insurance (Medicover) 
• We work with global top 500 companies (R&D) and leading academic institutions, giving you a chance to gain insights into these dynamically evolving industries. 
• Inspiring working environment - leisure and recreation area, playing corner for children, English lessons, yearly user conference with social programs, innovation days 
• You will be a valued member of a creative and supportive agile team 
• Everyday use of English in a multicultural environment

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.