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Data Science & Analytics Topics

Statistical analysis, data analytics, big data technologies, and data visualization. Covers statistical methods, exploratory analysis, and data storytelling.

Analysis to Recommendation and Decision Framing

Ability to move from analysis to a concise, justified recommendation and a pragmatic plan for decision and implementation. Candidates should lead with a clear recommendation or conditional decision, support it with evidence and trade offs, quantify expected business impact, estimate effort and time horizon, and state assumptions and limitations. The skill set includes proposing prioritized action plans and alternative options, anticipating objections, defining monitoring and rollback strategies, translating technical remediation or risk into business terms and measurable success metrics, and tailoring recommendations to stakeholder needs and constraints.

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Engineering and Business Outcomes

How engineering work and technical decisions translate into measurable business outcomes and how to demonstrate that linkage. Topics include mapping architecture choices, reliability, performance improvements and developer productivity initiatives to business metrics such as revenue, customer engagement, time to market, cost reduction and customer satisfaction. Candidates should be able to identify engineering metrics to track including latency, availability, error and incident rates, cycle time and deployment frequency, explain instrumentation strategies to capture signals, design measurement plans and experiments to establish causal impact, and attribute observed changes to specific engineering efforts. This topic also covers communicating technical tradeoffs and impact to nontechnical stakeholders, choosing appropriate granularity for measurement, and describing concrete initiatives with their measurement approach and quantified business impact.

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Structured Query Language Fundamentals and Aggregation

This topic covers core Structured Query Language fundamentals for analytical querying and reporting. Candidates should be able to write correct, readable, and maintainable SELECT queries with filtering using WHERE, sorting with ORDER BY, grouping with GROUP BY, and group filtering with HAVING. They should apply aggregate functions such as COUNT, COUNT DISTINCT, SUM, AVG, MIN, and MAX and understand how NULL values affect results, how empty result sets behave, and when to use different counting approaches. The scope includes date and time filtering, basic cohort segmentation, and common time based comparisons used to compute metrics such as daily active users, average revenue per user, and period over period comparisons. Candidates are expected to use basic joins and join predicates including inner joins and left joins, write simple subqueries and conditional expressions, and perform common data transformation and cleansing patterns to prepare data for analysis. Finally, this topic assesses query readability and maintainability practices such as aliasing and formatting, plus awareness of elementary performance considerations including index usage and avoiding unnecessary full table scans for entry to mid level analytical tasks.

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Analytical Background

The candidate's approach to analytical, evidence-based problem solving: how they take an ambiguous question, break it into testable pieces, gather and examine relevant information or data, choose appropriate methods to reach a conclusion, and turn that conclusion into a concrete recommendation or decision. This can show up as quantitative work (statistics, data analysis, experimentation, dashboards) or as qualitative and domain-specific analysis (reviewing logs or incidents, case or contract research, market or process analysis, root-cause investigation). Draw on academic projects, internships, or professional work. Focus on the end-to-end path: how the question or hypothesis was framed, what evidence was examined and with what tools or methods, what trade-offs were considered, and how the resulting insight changed a real decision or outcome.

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Metrics Selection and Dashboard Storytelling

Focuses on selecting metrics and designing dashboards and reports that directly support stakeholder decision making. Candidates should be able to identify distinct audiences and the specific decisions each audience must make, choose actionable metrics rather than vanity metrics, and balance leading indicators with lagging indicators as well as strategic metrics with operational metrics. This topic covers defining key performance indicators and targets and justifying each metric by the decision it enables, setting data freshness requirements and update cadence, and ensuring instrumentation and data quality to make metrics reliable. It includes dashboard architecture and visual narrative design such as layering from high level summaries to detailed drill down, tailoring views for executives, managers, and operational teams, selecting appropriate visualizations and annotations to guide interpretation, and enabling root cause analysis. Reporting practices are covered, including formatting, distribution channels, and alerting. Governance and metric definition topics include creating a single source of truth, assigning ownership, documenting definitions, and change control. Candidates must also recognize metric interactions and common pitfalls that can make metrics misleading such as aggregation bias, sampling issues, correlation versus causation, and perverse incentives, and propose mitigations. Interview questions typically ask candidates to design metric sets and dashboards for hypothetical scenarios, explain why metrics were chosen based on decisions they support, and describe cadence, distribution, drilling, and governance approaches.

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Trend Analysis and Anomaly Detection

Covers methods for detecting and interpreting deviations in metric behavior over time and determining whether changes reflect real product or user behavior versus noise. Topics include baseline establishment, seasonality and holiday effects, time series decomposition, smoothing and aggregation choices, statistical detection techniques such as control charts, z scores, EWMA and CUSUM, thresholding strategies, and modern algorithmic approaches like isolation forest or LSTM-based detectors. Also covers visualization and dashboarding practices for communicating trends, setting sensible alerting rules, triage workflows for investigating anomalies, and assessing business impact to prioritize fixes or rollbacks.

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Data Investigation and Root Cause Analysis

Techniques and a structured process for diagnosing an unexpected change in a metric, dataset, or system signal using quantitative evidence complemented by qualitative signals. Candidates should demonstrate how to validate that an observed change is a real signal and not noise, or a reporting, instrumentation, or pipeline problem, by checking data quality, event or record counts, sampling, schema stability, and pipeline or data-flow integrity. Describe slicing and decomposition strategies such as cohort or population segmentation, geography and platform segmentation, feature-level analysis, time series decomposition to separate trend and seasonality, funnel and velocity analysis, retention analysis, and variance analysis. Explain how to form, prioritize, and test hypotheses; design diagnostic queries and tests using structured query language or equivalent tooling; and correlate the change with plausible triggers such as releases or deployments, configuration or schema changes, experiments, campaigns, upstream system incidents, or external events. Include how to combine quantitative findings with qualitative evidence such as interviews, logs, session or trace replay, support tickets, or incident timelines to strengthen causal inference. Finally, cover communicating concise findings and actionable recommendations to stakeholders, creating reproducible queries and monitoring dashboards, alerts, or runbooks, and mentoring others on a systematic investigation approach. This applies broadly to investigating anomalies in business metrics, product data, system or service health signals, financial figures, or model performance, not only one of these domains.

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