TypeORM

TypeORM interviews cover decorator entities, repositories, migrations, and query builder escape hatches. Familiar to many Node codebases but requires care around lazy loading, transactions, and generated migrations.

Subtopics: entities, repositories, migrations, query builder.

On interviews: explain entity relations, transactional EntityManager usage, and when repository helpers are insufficient.

Common pitfalls: `synchronize` in production; lazy relations in serializers; repository calls outside active transactions.

The trade-off is rapid entity mapping versus hidden query and migration risks.

Checklist:

• Map constraints and indexes explicitly.
• Use transactional managers in units of work.
• Review generated migration SQL.
• Drop to query builder for complex reads.