---
title: "Building Reliable Mobile Applications"
description: "Shopify’s Point Of Sale (POS) app is mission-critical for brick-and-mortar merchants, because downtime can create long lineups, unhappy customers, and lost sales. Unlike server-side systems, mobile fixes depend on Apple and Google review, and merchants may delay installing approved updates, so the team focuses on preventing bugs and shortening recovery time. Its practices include layered automated and manual testing, component ownership with automatic Code Owners reviews, automated mobile “tophatting,” and weekly releases supported by a rotating Release Captain and ShipIt Mobile. Staged rollouts, beta flags, minimum-version enforcement for rare critical security fixes, and dedicated Primary and Secondary ATCs limit exposure and clarify incident response. ChatOps-based incident channels capture findings for root cause analysis, while rotating on-call responsibilities reduce context switching; these measures helped the app scale to larger merchants while shipping faster and improving reliability."
---

# Building Reliable Mobile Applications

[Shopify](https://yomu.fyi/company/shopify) · 2023-10-18 · Aug 14, 2020

**Type:** Explainer

## Summary

Shopify’s Point Of Sale (POS) app is mission-critical for brick-and-mortar merchants, because downtime can create long lineups, unhappy customers, and lost sales. Unlike server-side systems, mobile fixes depend on Apple and Google review, and merchants may delay installing approved updates, so the team focuses on preventing bugs and shortening recovery time. Its practices include layered automated and manual testing, component ownership with automatic Code Owners reviews, automated mobile “tophatting,” and weekly releases supported by a rotating Release Captain and ShipIt Mobile. Staged rollouts, beta flags, minimum-version enforcement for rare critical security fixes, and dedicated Primary and Secondary ATCs limit exposure and clarify incident response. ChatOps-based incident channels capture findings for root cause analysis, while rotating on-call responsibilities reduce context switching; these measures helped the app scale to larger merchants while shipping faster and improving reliability.

## Context

Shopify’s POS app supports brick-and-mortar merchants and is mission-critical because downtime can cause long lineups, unhappy customers, and lost sales. Mobile applications cannot be updated as quickly as server-side systems because releases require Apple or Google review, and merchants may postpone installation for weeks or months.

## Approach / What changed

The team combines layered automated and manual testing, component ownership and Code Owners reviews, automated mobile tophatting, weekly releases, Release Captain and ShipIt Mobile workflows, staged rollouts, beta flags, minimum-version enforcement for rare critical security issues, dedicated ATCs, and ChatOps-based incident management with root cause analysis.

## Takeaways

- Weekly releases reduced the amount of manual testing required, lowered pressure around release-train deadlines, and allowed non-critical bug fixes to ship within days instead of a month.
- Release Captain rotates the operational work of preparing, testing, submitting, and monitoring releases, while ShipIt Mobile automates much of the process and enables release candidates and submissions with a few clicks.
- Primary and Secondary ATCs handle production investigation and escalation, reducing context switching for the wider team; incidents use a dedicated Slack channel and are followed by no-blame root cause analysis.

**Tags:** [CI/CD](https://yomu.fyi/topic/ci-cd), [Incident Response](https://yomu.fyi/topic/incident-response), [Reliability](https://yomu.fyi/topic/reliability), [Testing](https://yomu.fyi/topic/testing)

- Source: [Shopify](https://shopify.engineering/making-shopify-point-of-sale-reliable)
- Source URL: https://shopify.engineering/making-shopify-point-of-sale-reliable
- Ingested by Yomu: 2026-08-31T01:11:59.431Z

[Read original post](https://shopify.engineering/making-shopify-point-of-sale-reliable)