Schema & API Design
The bridge between object design and system design. Master database schema design, REST/gRPC contract design, and the interface contracts that connect your well-designed components to the outside world.
ER Diagrams & Schema Design for LLD
Translate an object model into a database schema: entity-relationship diagrams, normalization trade-offs, indexing strategy, soft deletes, audit columns, and zero-downtime migrations.
REST API Contract Design
Design clean, consistent, versioned REST APIs: resource naming, idempotency, pagination strategies, error response shape, versioning, and OpenAPI contract-first design.
gRPC & Protobuf Contract Design
Design service contracts with Protocol Buffers: .proto file design, the four RPC types, field-numbering backward compatibility, versioning, and gRPC vs REST trade-offs.
UML Diagrams for LLD Interviews
The reference guide for reading and drawing the UML diagrams that matter in LLD interviews: class, sequence, state, and activity diagrams, and when each one earns its place.