Preparing for an interview at National Oilwell Varco requires a balanced approach. You must demonstrate strong software engineering fundamentals while showing a genuine interest in the physical systems and industrial applications that define the company's business.

Role-Related Knowledge – You must have a strong grasp of core programming languages (such as C#, C++, or Go) and database technologies (SQL). Be prepared to discuss your resume in detail, explaining not just what you built, but why you made specific architectural decisions and how you measured success.

Problem-Solving & Adaptability – Interviewers look for candidates who can think on their feet. If you are asked about a technology you do not know, be honest, but emphasize your ability to learn quickly. Demonstrating a proactive, hands-on learning mindset is highly valued.

Collaboration & Communication – Because software engineers at NOV work closely with multi-disciplinary teams (including mechanical and electrical engineers), you must be able to translate complex software concepts into clear, accessible language. Focus on showing that you are down-to-earth, respectful, and eager to collaborate.

Industrial Curiosity – Showing enthusiasm for the scale and complexity of NOV's physical machinery is a major differentiator. Research the company's main business segments, such as Rig Technologies and Wellbore Technologies, and prepare thoughtful questions about how software drives efficiency in these areas.

The interview process at National Oilwell Varco is designed to be straightforward, practical, and conversational. The company places a high priority on finding candidates who are a strong cultural fit and possess solid technical foundations without relying heavily on overly academic or trick-based testing.

The typical process moves through the following stages:

• Initial Screening: A brief phone call with HR or a hiring manager to review your background, discuss your career goals, and ensure alignment on the role's requirements.
• Technical Evaluation: Depending on the team, this may involve a short online coding challenge, a take-home practical test, or a technical phone interview focusing on OOP, SQL, and system design.
• Onsite / Panel Interview: A deeper, multi-hour round (often held in person at a local facility, such as in Houston, TX, Leduc, AB, or Stavanger, Norway). This round typically includes behavioral discussions, whiteboard problem-solving, and a panel interview with engineering leads and managers.
• Facility Tour & Wrap-up: At many locations, the onsite interview concludes with a tour of the local manufacturing plant or engineering facility, giving you a chance to see the equipment your software will support.

The visual timeline above outlines the standard progression from your initial application to the final offer. While the overall structure remains consistent, some teams may adjust the technical evaluation stage to include a live whiteboard session or a take-home assignment tailored to their specific product line.

To excel in the National Oilwell Varco interview process, you must understand the specific areas where interviewers focus their evaluation.

Software Engineering & OOP

This area tests your ability to write clean, maintainable, and efficient code. Interviewers want to see that you understand how to structure software using robust design patterns.

Be ready to go over:

• Object-Oriented Design – Deep understanding of encapsulation, inheritance, polymorphism, and abstraction.
• Language Proficiency – Strong command of the primary language listed in the job description (typically C#, C++, or Go), including memory management and concurrency.
• Software Architecture – Knowing how to structure applications for testability, scalability, and long-term maintenance.

Example scenarios:

• Designing a class structure to represent different types of drilling sensors, ensuring that new sensor types can be added with minimal code changes.
• Refactoring a tightly coupled piece of code to improve its modularity and testability.

Database Management & SQL

Data integrity and retrieval speed are critical when monitoring active industrial operations. You will be evaluated on your ability to work with relational databases.

Be ready to go over:

• Query Optimization – Writing efficient queries, utilizing indexes, and avoiding common performance bottlenecks.
• Data Manipulation – Understanding the exact differences between database commands and how they affect system logs and transactions.
• Relational Design – Designing schemas, setting foreign keys, and ensuring normalization.

Example scenarios:

• Writing a complex SQL query to join operational data from multiple tables and filter out anomalous sensor readings.
• Explaining how you would design a database schema to store time-series data from offshore machinery.

Hardware-Software Integration & System Physics

For roles close to the hardware layer, interviewers will evaluate your comfort level with physical systems and basic engineering math.

Be ready to go over:

• Basic Circuits – Understanding voltage, current, resistance, and power calculations (Ohm's Law).
• Physical Calculations – Basic physics concepts, such as calculating volumes, pressures, or forces, which are common in drilling and completions software.
• Hardware Communication Protocols – General awareness of how software sends and receives data from physical devices.

Example scenarios:

• Calculating the pressure drop in a system based on physical inputs provided during a whiteboard exercise.
• Explaining how your software would handle a sudden loss of connection to a physical hardware sensor.

Behavioral & Cultural Fit

NOV values down-to-earth, collaborative, and highly motivated engineers. They want to ensure you will integrate well with the existing team and handle operational pressures.

Be ready to go over:

• Rapid Learning – Demonstrating how you quickly pick up new technologies, languages, or domain knowledge.
• Conflict Resolution – Navigating differing opinions on technical designs within a team.
• Adaptability – Staying productive and positive when project scopes or deployment environments change.

Example scenarios:

• Describing a past project where you had to deliver a working prototype in a very short timeframe using a technology you had never used before.
• Discussing how you handle the stress of knowing your software is running on critical, high-risk industrial equipment.