How to Pass the A2A Software Engineer Interview in 2026

A2A manages a grid with many substations. Each substation has sensors reporting temperature and voltage. Write a function that takes a list of substation readings (each with substation ID, timestamp, sensor type, value) and identifies substations that have experienced a 'critical event'. A critical event is defined as: (1) temperature exceeding a high threshold AND voltage dropping below a low threshold within a 5-minute window, OR (2) temperature exceeding a very high threshold at any point. Ensure your code is clean, well-tested, and handles edge cases.

A strong answer shows: Ability to write clean, readable, and maintainable code.; Proficiency in handling time-series data and complex conditional logic.; Strong testing practices, including edge case coverage.; Algorithmic thinking for efficiency.; Debugging skills..

A2A is deploying smart meters that generate a high volume of time-series data. Design a scalable time-series database solution to store and query this data efficiently for analysis and reporting. Consider aspects like data ingestion rate, query patterns (e.g., range queries, aggregations), data retention policies, and potential for anomaly detection.

A strong answer shows: Knowledge of specialized databases and their use cases.; Understanding of performance optimizations for time-series data.; Ability to design for high write throughput and complex read queries.; Consideration of storage costs and data lifecycle management..