---
title: "Writing Better, Type-safe Code with Sorbet"
description: "Ruby repositories can hide unsafe method calls and ambiguous data shapes when types are inferred from variable names alone. Sorbet static type checking addresses these risks with method signatures, typed structs, enums, and interfaces. It can flag a potentially nil return before a chained call, distinguish database output fields from input fields, and enforce contracts for synchronous and asynchronous indexers in a dependency-injected hexagonal structure. The article also describes Sorbet’s gradual typing, including five strictness levels and namespace-by-namespace adoption using the minimum typed level of true. The stated conclusion is that enforced type safety catches errors unit tests may miss and helps prevent unsafe code from reaching production."
---

# Writing Better, Type-safe Code with Sorbet

[Shopify](https://yomu.fyi/company/shopify) · 2023-10-18 · Jun 24, 2020

**Type:** Explainer

## Summary

Ruby repositories can hide unsafe method calls and ambiguous data shapes when types are inferred from variable names alone. Sorbet static type checking addresses these risks with method signatures, typed structs, enums, and interfaces. It can flag a potentially nil return before a chained call, distinguish database output fields from input fields, and enforce contracts for synchronous and asynchronous indexers in a dependency-injected hexagonal structure. The article also describes Sorbet’s gradual typing, including five strictness levels and namespace-by-namespace adoption using the minimum typed level of true. The stated conclusion is that enforced type safety catches errors unit tests may miss and helps prevent unsafe code from reaching production.

## Context

Ruby code that relies on inferred variable names and untyped hashes can obscure method return types, optional fields, enum constraints, and the differences between data variants. The repository’s dependency-injected hexagonal structure also requires explicit contracts between components.

## Approach / What changed

The team adopted Sorbet static type checking through method signatures, typed Sorbet structs, enums, interfaces, and gradual file-by-file typing. Adoption proceeds namespace by namespace, upgrading files to at least the true level when related work requires them; GraphQL is also used for type contracts between services.

## Takeaways

- Sorbet can reject a chained call when a method signature permits nil, reducing reliance on trivial unit tests for every return case.
- Typed structs distinguish input ads from database-returned ads, while enums constrain state values and make nullable fields explicit.
- Sorbet interfaces require synchronous and asynchronous indexers to implement the expected method and return types, supporting dependency injection and polymorphism.

**Tags:** [Architecture](https://yomu.fyi/topic/architecture), [Ruby](https://yomu.fyi/topic/ruby), [Sorbet](https://yomu.fyi/topic/sorbet), [Static Typing](https://yomu.fyi/topic/static-typing)

- Source: [Shopify](https://shopify.engineering/writing-better-type-safe-code-with-sorbet)
- Source URL: https://shopify.engineering/writing-better-type-safe-code-with-sorbet
- Ingested by Yomu: 2026-08-31T01:12:24.253Z

[Read original post](https://shopify.engineering/writing-better-type-safe-code-with-sorbet)