Rotational Network Engineer Program Overview

Network Engineer Role at Meta

• Implement solutions quickly while considering long-term infrastructure needs (e.g., 5-year plans).
• Account for space, power, and cooling in data centers (DCs).
• Adapt to constantly evolving technologies to ensure secure and reliable network capacity.

Data Center Fabric

• Interconnected switches and routers that support network traffic.
• Designed to be modular for easy management and maintenance via software.

Backbone Network

• Interconnects data centers and points of presence (POPs) globally.
• Treated differently from the DC network.
• Meta operates one of the largest scale DC and backbone networks in the world.

Rotational Network Engineer (RNE) Program Overview

• Ensuring network reliability, robustness, and scalability to serve over a billion users.
• Developing and deploying network designs, automation systems, and performance improvements.
• Scale is tremendous; automation and continuous improvement are crucial to meet demands.

Network Organization at Meta

• Networking Infrastructure:
  • Network Core Services
  • Platform Engineering
  • Data and Networking
  • Network Planning
  • Traffic and Edge
  • Network Security
  • Network Investments (requires longer experience, less relevant for RNEs)
• Diverse objectives across teams.
• RNE program exposes engineers to most of these areas.

RNE Program Details

• Full-time, paid position with the same expectations as full-time employees.
• Four to six-month rotations to explore different areas of network engineering.
• Mentorship is provided for career guidance and navigation.

RNE Onboarding and Rotation Process

• Three-week boot camp for all new engineers.
• Work with various teams on tasks and projects during rotations.
• Soft team matching to identify areas of interest.
• Final rotation project (RNE graduation project).
• Full team matching after graduation.

RNE Team Options

• Backbone Engineering
• DBE
• Network Core Service (NCS)
• Data Center Network Engineering
• Network Security
• Traffic and Edge
• And more

RNE Eligibility

• For early-career individuals and recent graduates.
• Also suitable for those with a few years of industry experience.

RNE vs. Direct Team Match

• If a candidate has specific network expertise and matches a team directly, the RNE program may not be necessary.
• RNE is not an interview process but a working opportunity to explore teams.

Networking Interview Process

• 1-on-1 video conference interviews (45 minutes each).

Networking Fundamentals Interview

• Focus on:
  • ARP
  • DNS
  • DHCP
  • NAT
  • IPv4/IPv6
  • TCP
  • BGP and other basic routing protocols
• Opportunity to ask questions.

Networking Fundamentals Tips

• Ask clarifying questions.
• Verbalize assumptions before providing a solution to allow the interviewer to follow along.
• Be prepared to explain in detail.
• Review interview preparation materials.

Network Design Interview

• Focus on designing networks or systems to operate at scale.
• Designing network elements or systems with reliability, scale, and efficiency in mind.
• Opportunity to ask questions.

Network Design Tips

• Clarify goals and requirements of the system.
• Only ask questions that might affect the design.
• Describe the system at a high level and explain the overall architecture.
• Draw diagrams that clearly describe relationships among different components.
• Prioritize a working solution, focus on scalability.
• Identify trade-offs in the design and describe how decisions were made.
• Calculate back-of-the-envelope resource estimates.
• Adjust the design based on changing requirements or constraints.
• Determine how the system will perform at scale and identify bottlenecks.
• Familiarize yourself with the xCairo virtual whiteboard tool.

Coding Interview

• 1-on-1 video conference (45 minutes).
• Assess problem-solving skills and limits of knowledge.
• Repeat the question to ensure understanding.
• Ask about edge cases.
• Think out loud while coding.
• Run test cases through the code.

Coding Environment

• CodaPad: A whiteboard tool without autocomplete or execution.
• The goal is to understand the problem, express thoughts, and test the solution manually.

Coding Example: Facebook Logo Stickers

• Problem: Facebook logo stickers cost 2. Cut out letters to make other words/phrases.
• Input: String of word(s) made from letters in "facebook" (lowercase).
• Output: Integer representing the number of stickers needed.
• Example: "coffee kebab" requires 3 stickers (c, o, three f, k, two b, a).
• Example: "book" requires 1 sticker.
• Example: "facebookbook" requires 2 stickers.

Coding Solution Outline

1. Create a function get_letter_count(word) to map character occurrences in a word.
   • Example: `getlettercount(