Google Software Engineer Interview Questions

Convert an auto-incrementing 64-bit integer ID into a alphanumeric short string using Base62 encoding. To eliminate database write bottlenecks caused by generating sequential IDs at high volumes, implement a distributed unique ID allocator system (like Apache ZooKeeper) to hand out discrete ID ranges to independent worker application servers. Store the core key-value mappings inside an optimally sharded NoSQL store like Google Cloud Bigtable, and cache hot mappings using a global edge CDN network to handle heavy read traffic.

Establish persistent, bi-directional communication channels using WebSockets or gRPC streams managed by a horizontal layer of stateless connection gateway instances. Manage active user presence states via distributed heartbeats written to a Redis cluster. Read and write high-volume real-time message streams through a distributed commit log (like Apache Kafka) for fan-out processing, and store message histories inside a wide-column NoSQL database like Apache Cassandra to handle high-frequency append operations.

Implement a conflict resolution strategy using Operational Transformation (OT) for centralized, server-ordered synchronization architectures (like Google Docs), or Conflict-free Replicated Data Types (CRDTs) for highly distributed, peer-to-peer style topologies. The backend connection layer pushes real-time document mutations through a centralized message broker to assign strict chronological sequence versions. These updates are logged in a memory cache before being flushed to a persistent document storage engine.

Build a distributed ingestion pipeline using an asynchronous message queue architecture. When a video is uploaded, split the file into uniform 5-second segments to allow for parallel processing. Transcode these chunks concurrently across a pool of worker nodes into multiple targeted resolution profiles (like 1080p, 4K) and optimized encoding formats (such as H.264, VP9). Store final video files in a scalable blob storage tier, and distribute them to end users via a geo-distributed CDN network using adaptive bitrate protocols like HLS or DASH.

When facing highly ambiguous engineering initiatives, adopt a proactive approach to establish clear goals. Start by drafting a 1-page technical requirement document that lists explicit design assumptions, architectural constraints, and success metrics. Gather early cross-functional feedback by sharing this specification through an asynchronous RFC loop with stakeholders. Next, rapidly build a minimal, unoptimized functional prototype to surface hidden edge cases early, which turns abstract requirements into structured project milestones.