Build the data-plane infrastructure behind Google Cloud's NAT gateways (PSC, Cloud NAT)

Own core data-plane software for Google Cloud's Andromeda network stack, focused on NAT-based products like Private Service Connect and Cloud NAT. This role sits at the intersection of systems programming and large-scale networking, with production on-call responsibility for a service that gates traffic for enterprise customers in 200+ countries.

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Likely format

Typical Google SWE loop: phone screen(s) with coding, followed by an onsite/virtual onsite with multiple rounds covering coding, system design/googleyness, and behavioral (this JD does not itself specify a format).

What this interview tests

Cloud networking data plane (NAT, PSC)
Systems programming in C++ / Unix-Linux internals
Large-scale distributed systems design
Production on-call and incident troubleshooting
Networking protocols (TCP/IP, load balancers, SDN)

Common question themes

Design a scalable NAT gateway component

Debugging a kernel/user-space networking issue

Tradeoffs in optimizing a cloud networking datapath

Handling a production packet-latency incident on-call

Data structures & algorithms coding problem

How candidates describe it

Real Software Engineer III interview stories — retold from candidates' public write-ups, with sources.

Google · L4 Software Engineer, Google CloudOffer

Google L4 Cloud Software Engineer Interview: Downleveled to L3

A referred candidate interviewed for an L4 software engineer role on a Google Cloud team in Bangalore, going through a phone screen, three onsite coding rounds (the third left unfinished), and a culture conversation, only to have the hiring committee offer L3 instead of L4; the candidate obtained the compensation letter and declined the next day because the pay was below their current salary.

Interviewed 2021 · Bangalore, India

Google · L3 Software EngineerOffer

Google L3 software engineer interview: phone screen, four coding rounds, and the Googleyness round

A candidate with two years of experience went from recruiter outreach to offer over about four months. The onsite was four 45-minute coding rounds — three of them featuring binary trees — and one round turned into a 25-minute chain of follow-ups about approximating an optimal solution at scale.

Interviewed June 2020 · Bangalore, IN

Google · L4 Software EngineerNo offer

Google L4 Software Engineer Interview: Eight Rounds, No Offer

An L4 Software Engineer candidate went through two phone screens, three onsite rounds, a culture conversation, and a team-matching call with a Google hiring manager, then watched the process stall for about a month and a half over a tightened experience requirement before an added extended round ended without an offer.

Interviewed February 2024 · Not specified

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