What is a Data Scientist at Tempus AI?

At Tempus AI, the role of a Data Scientist is pivotal to the company's mission of bringing the power of data and artificial intelligence to healthcare. You are not simply optimizing ad clicks or user retention; you are working with one of the world's largest libraries of clinical and molecular data to personalize patient care. Whether you are aligned with Real World Data Science, Translational Research, or Pharma R&D, your work directly bridges the gap between complex biological data and actionable medical insights.

You will join a team that operates at the intersection of technology and biology. Data Scientists at Tempus drive the development of algorithms that structure unstructured clinical notes, analyze genomic sequencing data, and generate Real World Evidence (RWE) to support pharmaceutical partners. You will tackle challenges ranging from cohort selection for clinical trials to building predictive models that determine which therapies might work best for a specific cancer patient.

This role requires a unique blend of technical rigor and domain curiosity. You will work alongside software engineers, pathologists, and bioinformaticians to productize your models. The impact of your work is tangible: the insights you generate help physicians make real-time decisions and accelerate the discovery of new therapeutics.

Getting Ready for Your Interviews

Preparing for a Data Science interview at Tempus requires a shift in mindset. While standard machine learning proficiency is required, you must also demonstrate an aptitude for handling high-dimensional, messy, and biologically relevant data.

Key Evaluation Criteria:

Statistical and Machine Learning Depth – 2–3 sentences Interviewers will probe your understanding of the mathematical foundations behind the models you use. In the context of RWE and Translational Research, you must demonstrate expertise in areas like survival analysis, causal inference, and hypothesis testing, rather than just black-box deep learning.

Data Wrangling and Fluency – 2–3 sentences Healthcare data is notoriously unstructured and complex. You will be evaluated on your ability to manipulate data using SQL and Python (pandas), specifically your ability to clean, join, and make sense of disparate datasets like electronic medical records (EMR) and genomic panels.

Product and Scientific Communication – 2–3 sentences You must be able to translate complex statistical findings into clear narratives for non-technical stakeholders, such as clinicians or pharma clients. Tempus values candidates who can explain why a model works and what the clinical implications of a false positive might be.

Mission Alignment and Culture – 2–3 sentences Tempus is fast-paced and mission-driven. You will be assessed on your passion for precision medicine and your ability to thrive in an environment that combines the rigor of academia with the speed of a technology startup.

Interview Process Overview

The interview process at Tempus AI is designed to test both your technical capabilities and your ability to apply them to healthcare-specific problems. Generally, the process moves quickly, reflecting the company's startup roots. It typically begins with a recruiter screen to assess your background and interest in the intersection of AI and healthcare, followed by a technical screen.

The technical screen often involves a live coding session or a take-home challenge focused on practical data manipulation and analysis. Unlike general tech companies that focus heavily on algorithmic puzzles (LeetCode), Tempus tends to prioritize practical data science tasks—cleaning a dataset, performing exploratory analysis, and building a baseline model. Following this, the onsite stage (virtual or in-person) consists of a series of panels covering technical depth, case studies, and behavioral fit.

Throughout the process, expect a collaborative atmosphere. Interviewers are looking for problem solvers who can navigate ambiguity. You will likely speak with cross-functional team members, including other data scientists, engineers, and potentially domain experts like computational biologists, to ensure you can communicate effectively across disciplines.

This timeline outlines the typical flow from application to offer. Use this to gauge where you are in the pipeline and prepare your energy for the intensive onsite loop. Note that the specific technical assessments may vary slightly depending on whether you are interviewing for the RWE or Translational Research teams.

Deep Dive into Evaluation Areas

To succeed, you need to prepare for specific technical domains that are heavily emphasized at Tempus. Based on candidate reports and job requirements, the following areas are critical.

Statistical Modeling & Machine Learning

This is the core of the interview. You need to show that you understand the "under the hood" mechanics of algorithms, not just how to import them. Because Tempus deals with patient lives, interpretability and robustness are often more important than raw prediction accuracy.

Be ready to go over:

• Classical Machine Learning – Random Forests, Gradient Boosting (XGBoost/LightGBM), and Logistic Regression are workhorses here. Know their hyperparameters and failure modes.
• Survival Analysis – Kaplan-Meier curves and Cox Proportional Hazards models are essential for oncology data.
• Causal Inference – Understanding the difference between correlation and causation, especially in observational studies (RWE).
• Advanced concepts – Bayesian statistics, dimensionality reduction (PCA/t-SNE for genomic data), and NLP (for processing clinical notes).

Example questions or scenarios:

• "How would you handle class imbalance in a dataset where the positive outcome (e.g., a specific rare mutation) is less than 1%?"
• "Explain the difference between L1 and L2 regularization and when you would use each."
• "How do you validate a model when your training data has a different distribution than your real-world test data?"

Coding & Data Manipulation

Expect practical coding questions. You will likely be asked to manipulate data in Python or SQL. The focus is on data intuition—how you handle missing values, duplicates, and messy strings.

Be ready to go over:

• Pandas Proficiency – Groupby, pivot tables, merging dataframes, and handling datetime objects.
• SQL Complexity – Writing queries involving multiple joins, window functions, and CTEs to extract cohorts from a database.
• Data Cleaning – Strategies for imputing missing clinical data (e.g., missing lab vitals).

Example questions or scenarios:

• "Given a dataset of patient visits, write a query to find the time elapsed between the first and second visit for each patient."
• "Here is a CSV with messy clinical notes. Write a Python script to parse out the medication names and dosages."
• "How would you optimize a slow SQL query running on a table with billions of rows?"

Case Studies & Product Sense

These interviews test your ability to translate a vague business or clinical problem into a data science problem. You will be given a scenario relevant to Tempus's work and asked to design a solution end-to-end.

Be ready to go over:

• Metric Definition – Choosing the right metric for success (e.g., F1-score vs. Accuracy in medical diagnosis).
• Study Design – How to select a control arm for a study using retrospective data.
• Feasibility – Assessing whether the data available is sufficient to answer the question asked.

Example questions or scenarios:

• "A pharma partner wants to know if Drug A works better than Drug B for a specific lung cancer subtype. How do you design this analysis using our database?"
• "We want to build a model to predict sepsis in ICU patients. What features would you use, and how would you structure the target variable?"

Key Responsibilities

As a Data Scientist at Tempus, your daily work revolves around extracting value from the company's massive multimodal dataset. You will spend a significant amount of time structuring and cleaning data, as clinical data is inherently messy. This involves writing pipelines to ingest data from EMR systems, pathology reports, and genomic sequencers.

You will collaborate closely with the Engineering and Product teams to deploy models into production. For a role in Real World Evidence (RWE), you will design retrospective studies to support pharmaceutical regulatory submissions, requiring strict adherence to statistical rigor. If you are in Translational Research, you might focus on discovering biomarkers that predict patient response to immunotherapy, working alongside biologists to validate your findings.

Communication is a major component of the job. You will frequently present your findings to internal stakeholders and external partners. You are expected to be the "voice of the data," guiding teams away from spurious correlations and toward statistically sound conclusions that can withstand clinical scrutiny.

Role Requirements & Qualifications

Tempus seeks candidates who are technically versatile and scientifically literate. The ideal candidate blends the engineering skills of a developer with the statistical mindset of a researcher.

• Technical Skills – Strong proficiency in Python and SQL is non-negotiable. You should be expert in the data science stack (pandas, NumPy, scikit-learn). Experience with deep learning frameworks (PyTorch, TensorFlow) is often required for roles involving imaging or NLP.
• Experience Level – Typically, candidates for "Data Scientist II" roles have 2+ years of industry experience or a relevant PhD. A background in Computational Biology, Bioinformatics, or Epidemiology is highly valued but not always strictly required if your technical skills are top-tier.
• Soft Skills – You must possess strong storytelling abilities. The capacity to explain technical trade-offs to non-technical audiences is essential.
• Must-have vs. Nice-to-have –
  • Must-have: Strong stats fundamentals, SQL/Python fluency, experience with predictive modeling.
  • Nice-to-have: Experience with genomic data (DNA/RNA-seq), familiarity with cloud platforms (AWS/GCP), and knowledge of the drug development lifecycle.

Common Interview Questions

The following questions are representative of what you might face. They are drawn from typical patterns in the precision medicine and data science space. Do not memorize answers; instead, use these to practice your problem-solving process.

Statistics & Probability

• Explain the Central Limit Theorem and why it is useful in analyzing clinical data.
• What is the difference between Type I and Type II errors? Which is worse in the context of cancer diagnosis?
• How would you assess whether two survival curves (Kaplan-Meier) are significantly different?
• Explain the concept of p-value to a non-technical doctor.
• How do you handle multicollinearity in a regression model?

Machine Learning & Algorithms

• Describe the difference between bagging and boosting.
• How would you build a model to predict patient readmission within 30 days?
• What metrics would you use to evaluate a model for a rare disease classification?
• Explain how a Random Forest decides where to split a node.
• How do you handle missing data in a time-series dataset (e.g., patient vitals)?

Coding & SQL

• Write a SQL query to find the top 3 most common cancer types in our database for patients under 50.
• Given two tables, Patients and Visits, write a query to return patients who have not visited in the last year.
• Write a Python function to tokenize and clean a string of clinical text.
• How would you merge two pandas dataframes with different indices and handle the resulting NaNs?

Behavioral & Situational

• Tell me about a time you had to explain a complex technical concept to a stakeholder who didn't understand it.
• Describe a project where you had to work with very messy or incomplete data.
• Why do you want to work in the healthcare space specifically?
• How do you prioritize tasks when you have multiple deadlines from different teams?

Frequently Asked Questions

Q: Do I need a background in Biology or Medicine to apply? No, a biology background is not strictly mandatory for all Data Science roles, but it is a significant advantage. If you lack this background, you must demonstrate a strong willingness to learn the domain quickly and an ability to pick up complex terminology.

Q: What is the typical interview timeline? The process is generally efficient. You can expect the timeline from the initial recruiter screen to the final offer to take anywhere from 3 to 5 weeks, depending on team availability and scheduling.

Q: Is the coding interview LeetCode-style or practical? Tempus leans heavily toward practical coding. While you should know basic data structures, you are more likely to face data manipulation tasks (pandas/SQL) or a practical take-home assignment than obscure dynamic programming puzzles.

Q: What is the work culture like for Data Scientists? The culture is hybrid—part academic research lab, part fast-growth tech company. It is collaborative and intellectual, with a heavy emphasis on cross-functional teamwork. Expect to be challenged and to learn something new every day.

Q: Does Tempus offer remote positions? Yes, Tempus offers remote and hybrid options, though specific requirements depend on the team. Some roles, particularly those working closely with wet labs, may have more on-site requirements in hubs like Chicago, Boston, or Redwood City.

Other General Tips

• Know the Domain: You don't need to be an MD, but you should read up on the basics of precision medicine. Understand what Real World Evidence (RWE) is and why it matters to pharmaceutical companies.
• Focus on Impact: When answering behavioral questions, frame your achievements in terms of impact. Did your model save time? Did it improve patient matching? Tempus cares about outcomes.
• Be Honest About What You Don't Know: In science, intellectual honesty is crucial. If you don't know a statistical concept, admit it and explain how you would figure it out. Guessing is a red flag in a field where accuracy affects patient health.
• Prepare for "Why Tempus?": This is not a generic tech job. Have a compelling answer for why you want to apply your skills to cancer research and healthcare. Passion for the mission is a major differentiator.

Summary & Next Steps

Becoming a Data Scientist at Tempus AI is an opportunity to do the most meaningful work of your career. The role demands high technical proficiency, but it offers the reward of seeing your code potentially extend or save lives. By preparing deeply for statistical rigor, data manipulation, and domain-specific challenges, you can position yourself as a top candidate.

Focus your preparation on the practical application of machine learning to messy, real-world data. Brush up on your SQL, review your survival analysis, and be ready to discuss how you communicate complex ideas to diverse teams. Approach the interview with curiosity and confidence—you are applying to join a team that is redefining the future of medicine.

This salary data provides a baseline for compensation expectations. Keep in mind that Tempus AI typically offers a package that includes base salary, equity (stock options), and performance bonuses, which can vary significantly based on your experience level and location.

Good luck! With the right preparation, you have everything you need to succeed.