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WorkflowGen Mobile App Modernization

Services Covered:

Mobile Application Development • Staff Augmentation
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Industry
Industry

Software Development

Duration
Duration

4 months

Budget
Budget

50K - 199K

Start Date
Start Date

1 February 2021

Team Size
Team Size

1-5

Engagement Model
Engagement Model

Nearshore

Project Capability Score (PCS)

gauge meter
76/100
Good

Project Capability Score (PCS) estimates how capable Callstack is of successfully delivering a project like this, based on its past experience, track record, and ability to handle similar work. Learn more about PCS

Client

Advantys

mapParis, France

Project Summary

Advantys (WorkflowGen) hired Callstack to modernize their WorkflowGen mobile app by migrating the frontend to EXPO and TypeScript, adopting GraphQL code generation, and improving UI/UX. Callstack acted as staff augmentation (two front-end developers), migrated the stack, refreshed UI components, and improved performance, accessibility, and development velocity. The client praised Callstack's technical skills, collaboration, and recommended their services.

Key Challenges

  • Modernize an app built on a first-generation React Native stack to a modern, maintainable architecture.
  • Improve overall performance and UI/UX.
  • Migrate React Native/GraphQL architecture using EXPO, TypeScript, GraphQL code generator, React Query and React Native Paper to make the codebase easier to maintain and increase feature development velocity.

Project Deliverables

  • Migrated React Native codebase to Expo and TypeScript
  • Implemented GraphQL code generation and moved from Apollo to React-Query
  • Refreshed UI components using React Native Paper (Snackbar, Button, IconButton, Typography)
  • Replaced react-native-navigation with react-navigation
  • Ejected Expo for final testing and publishing while keeping Managed workflow for development

Project Solution

Callstack joined Advantys as staff augmentation responsible for the frontend of the WorkflowGen app. They migrated the GraphQL client from Apollo to React-Query, used GraphQL code generator to produce TypeScript types and operations, refreshed UI components with React Native Paper, replaced react-native-navigation with react-navigation, and ejected the Expo app for final testing while maintaining the Managed workflow during development.

Project Outcome

  • Migrated codebase from javascript/class components/apollo v1/redux (30K LOC) to typescript/hooks/react-query/GraphQL codegen/expo (25K LOC), reducing the code surface.
  • Dramatically improved UX with efficient data caching, auto re-fetching, dark mode support, accessibility, and internationalization.
  • Enabled Advantys' internal team to add new features to the new codebase without friction.

Platforms

  • MobileMobile

Tech Stack

  • TypeScriptTypeScript
  • GraphQLGraphQL
  • React NativeReact Native
  • ApolloApollo
  • ReduxRedux
  • ExpoExpo
  • React QueryReact Query
  • React NavigationReact Navigation

Client Endorsement

Overall Review Rating

5star

Timeliness

Cost Rating

Willing to Refer

Quality of Deliverables

The Callstack team achieved all our project goals and impressed us with the quality of their collaboration and strong technical skills. Our internal management has extensive industry experience and confidently recommends their services.

Arnaud Bezançon

Co-Founder & CTO

Note: This endorsement is based on publicly available client feedback from external review sources.