Systems Architecture & Distributed Systems Topics
Large-scale distributed system design, service architecture, microservices patterns, global distribution strategies, scalability, and fault tolerance at the service/application layer. Covers microservices decomposition, caching strategies, API design, eventual consistency, multi-region systems, and architectural resilience patterns. Excludes storage and database optimization (see Database Engineering & Data Systems), data pipeline infrastructure (see Data Engineering & Analytics Infrastructure), and infrastructure platform design (see Cloud & Infrastructure).
Scalability and Code Organization
Focuses on designing software and codebases that remain maintainable and performant as features and user load grow. Areas include modularity and separation of concerns, component and API boundaries, when and how to refactor, trade offs between monolith and service oriented architectures, data partitioning and caching strategies, performance optimization, testing strategies, dependency management, code review practices, and patterns for maintainability and evolvability. Interview questions may ask candidates to reason about design choices, identify coupling and cohesion issues, and propose practical steps to evolve an existing codebase safely.
Ad Server Simulation and Auction Mechanics Architecture
Explores the architecture of ad-serving platforms, including modeling and simulating ad server workloads, the real-time bidding (RTB) auction flow, ad exchange integrations, and the end-to-end pipeline from impression to bid decision. Covers low-latency design patterns, throughput and latency budgets, distributed components (ad server, DSP/SSP, bid stream processors), caching, data consistency, fault tolerance, sharding/partitioning, deployment strategies, telemetry and monitoring, testing approaches for high-frequency decisioning, and considerations for privacy and measurement accuracy within large-scale ad ecosystems.
Architecture and Technical Trade Offs
Centers on system and solution design decisions and the trade offs inherent in architecture choices. Candidates should be able to identify alternatives, clarify constraints such as scale cost and team capability, and articulate trade offs like consistency versus availability, latency versus throughput, simplicity versus extensibility, monolith versus microservices, synchronous versus asynchronous patterns, database selection, caching strategies, and operational complexity. This topic covers methods for quantifying or qualitatively evaluating impacts, prototyping and measuring performance, planning incremental migrations, documenting decisions, and proposing mitigation and monitoring plans to manage risk and maintainability.
Distributed Systems Fundamentals
Core principles and theory that underlie distributed computing systems. Includes understanding trade offs between consistency, availability, and partition tolerance, common consistency models such as eventual and strong consistency, replication and sharding strategies, load balancing and data partitioning, consensus algorithms and their guarantees, scalability and fault tolerance patterns, and how these concepts apply to infrastructure components such as databases, caches, service meshes, and load balancers. Candidates are expected to explain design choices, common failure modes, and how fundamental concepts influence architecture decisions for resilient and scalable systems.
Strategic Technical Decision Making
Focuses on higher level, organization impacting technical decisions and direction setting. Candidates should discuss evaluating long term implications, aligning technology choices with company strategy, managing uncertainty in multi year decisions, balancing innovation with operational risk, and communicating strategic rationale to leadership and across teams. Examples should show decisions that affected architecture, platform direction, or major product technical choices.
Trade Off Analysis and Decision Frameworks
Covers the practice of structured trade off evaluation and repeatable decision processes across product and technical domains. Topics include enumerating alternatives, defining evaluation criteria such as cost risk time to market and user impact, building scoring matrices and weighted models, running sensitivity or scenario analysis, documenting assumptions, surfacing constraints, and communicating clear recommendations with mitigation plans. Interviewers will assess the candidate's ability to justify choices logically, quantify impacts when possible, and explain governance or escalation mechanisms used to make consistent decisions.
Deep Technical Expertise and Project Mastery
In depth exploration of the candidate's most complex technical work and domain expertise. Interviewers will probe architectural decisions, design trade offs, performance and reliability considerations, algorithmic or model choices, and the reasoning behind technology selections. Candidates should be ready to walk through a single complex backend or artificial intelligence and machine learning system in detail, explain low level technical choices, discuss alternatives considered, describe challenges overcome, and justify outcomes. Expect follow up questions that test depth of understanding and the ability to defend decisions under scrutiny.
Technical Vision and Strategy
Covers long term technical direction, architecture choices, infrastructure and platform strategy, and how technical roadmaps align with business goals. Interviewers will probe your perspective on where technology is heading, major architectural trade offs, cloud and modernization approaches, and how you would shape the organization or team to meet future needs. At senior levels this includes strategic thinking beyond immediate problems, influencing cross team technical initiatives, prioritization of long term investments, and communicating a coherent technical roadmap.
Decision Making Under Uncertainty
Focuses on frameworks, heuristics, and judgment used to make timely, defensible choices when information is incomplete, conflicting, or evolving. Topics include diagnosing unknowns, defining decision criteria, weighing probabilities and impacts, expected value and cost benefit thinking, setting contingency and rollback triggers, risk tolerance and mitigation, and communicating uncertainty to stakeholders. This area also covers when to prototype or run experiments versus making an operational decision, how to escalate appropriately, trade off analysis under time pressure, and the ways senior candidates incorporate strategic considerations and organizational constraints into choices.