Callstack

BACKGROUND

Please describe your company and your position there.

Associate Director of App Development

OPPORTUNITY / CHALLENGE

For what projects/services did your company hire Callstack, and what were your goals?

We asked Callstack to:

• Migrate our super app and one mini app to Re.Pack
• Create in-house MoMo development platform
• Prepare documentation of the super app and mini app migration process
• Prepare and conduct an upskilling workshop for our developers

To achieve the following goals:

• migrate the MoMo super app and mini app to the separated repository with the help of Re.Pack library
• create a working sandbox development platform for MoMo available also for the third-party developers (outside MoMo)
• prepared a whole documentation for the chunk loader and end-to-end mini app migration process
• upskill the MoMo dev team by organizing a workshop session focused on migrating mini apps with Re.Pack

SOLUTION

How did you select this vendor and what were the deciding factors?

Very high level of technical skills

Describe the scope of work in detail, including the project steps, key deliverables, and technologies used.

At the beginning of our cooperation, the Callstack team did a huge research to first find out what needs to be done to successfully proceed the migration process. As a result, they divided the project into four main deliverables:

• Migration of platform (super app) and one mini app to Re.Pack
• Creation of the in-house development platform
• Prepare documentation of the migration
• Prepare and conduct upskilling workshop for MoMo developers team

How many resources from the vendor's team worked with you, and what were their positions?

One software engineer.

RESULTS & FEEDBACK

Can you share any measurable outcomes of the project or general feedback about the deliverables?

• Migration of platform (super app) and one mini app to Re.Pack
• Creation of a chunk manager  
• Integration of the chunk manager with the current manager
• Creation of the working assets loading mechanism for mini apps
• Creation of the in-house development platform
• Research on how to integrate a mini app with the development platform
• Setupping Re.Pack to build mini apps’ bundles.
• Handling RN debugger support, hot module reloading and devtools support.
• Prepare documentation of the migration
• Creation of the docs describing Chunk loader with the use of typedoc and ReadMe doc with the documentation of the migration process.
• Prepare and conduct upskilling workshop for MoMo developers team

Describe their project management style, including communication tools and timeliness.

We’ve had daily standups to determine next steps of the project, evaluate what has been done and to specify what we needed. To manage the tasks for the Callstack team in each of the four deliverables we’ve been using a board in Notion. Each of the deliverables was confirmed by the email. During our daily communication we’ve been using Google chat as it was the fastest way to discuss the current issues.

What did you find most impressive or unique about this company?

• very high level of level of technical skills and the quality of the collaboration
• impressive development pace while maintaining the highest quality requirements
• the development efforts have been wisely evaluated and the final costs are on track with the initial estimates.

We had been struggling with React Native application performance until we met Callstack. With the assistance of their experts and a professional process, our application performance had a significant improvement. Thanks, and I highly recommended them to anyone who was in a similar situation.

Are there any areas for improvement or something they could have done differently?

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BACKGROUND

Please describe your company and your position there.

I’m CTO, Creator of WorkflowGen, Advantys Co-founder. ADVANTYS works with organizations worldwide to address complex business processes with optimal engineering and tools. WorkflowGen is a leading digital process automation solution that lets organizations and IT providers design and deploy business-critical, process-driven web and mobile applications.

OPPORTUNITY / CHALLENGE

For what projects/services did your company hire Callstack, and what were your goals?

We asked Callstack to:

• modernize our WorkflowGen mobile app that relied on the first generation React Native technical stack
• improve the overall performance and UI/UX of their mobile app
• migrate existing React Native / GraphQL architecture with EXPO, Typescript, GraphQL code generator,

React Query and React Native Paper To achieve the following goals:

• make the codebase easier to maintain
• refresh the whole app by upgrading previously used libraries
• and improve the new features’ development velocity.

SOLUTION

How did you select this vendor and what were the deciding factors?

We have discovered Callstack via Open source projects like React Native Paper. The deciding factors were the very high level of technical skills and the overall project team responsiveness.

Describe the scope of work in detail, including the project steps, key deliverables, and technologies used.

Callstack developers joined Advantys’ inhouse devs team as a staff augmentation being the ones responsible for the frontend side of the WorkflowGen app update. Mostly, the cooperation was about discussing different ways for solving current issues and looking for the best possible solutions in terms of performance and UI/UX. The whole project was supervised by me - Co-founder and CTO of Advantys, being a project owner who explained to Callstack developers our needs and technical requirements.

React-Query as a GraphQL client We started from moving from using Apollo Client v1 to React-Query as a GraphQL client. GraphQL code generator has been using to generate from the GraphQL API schema the corresponding Typescript Types and operations. UI/UX Optimization Callstack team refreshed such elements of the app as Snackbar, Button, IconButton and Typography. All these elements were refreshed by using React Native Paper library.

Also, react-native-navigation has been replaced with react-navigation which contributed to the improvement of DX and also contributed to faster development of new features. Changes in react-native-webview code Callstack developers ejected the EXPO app. Luckily, it didn’t have a negative impact on DX so we could keep using EXPO Managed Workflow in the development process and Bare Workflow was used only for final testing and publishing the app. When it comes to Over-The-Air (OTA) updates, both Managed and Bare workflow cooperate with EXPO out of the box.

How many resources from the vendor's team worked with you, and what were their positions?

Two front-end developers.

RESULTS & FEEDBACK

Can you share any measurable outcomes of the project or general feedback about the deliverables?

Our React Native app code base has been migrated from

• javascript / class comp / apollo v1 / redux
• 30K loc to:
  • typescript / hooks / react-query / suspense / Graphql code gen / expo
  • 25K loc It translates to a modern technical stack with an high quality code (Typescript) while reducing the code surface.

The UX experience has been dramatically improved with an efficient data caching and auto re-fetching. The UI has also been improved with dark mode support, modern components and advanced accessibility and internationalization features. Advantys internal development team has been able to add new features to the new code base without frictions.

Describe their project management style, including communication tools and timeliness.

Callstack developers jumped into Advantys’ team structure as a staff augmentation being the ones responsible for the frontend side of the update. Usually, the cooperation was about discussing different ways for solving current issues and looking for the best possible solutions in terms of performance and UI/UX. The whole project was supervised by me (Co-Founder & CTO of Advantys) as a project owner who clearly explained to Callstack developers our needs. In addition to Github (issues, PRs, projects), Notion and Slack collaborative tools have been used to accelerate the team’s responsiveness.

What did you find most impressive or unique about this company?

• very high level of level of technical skills and the quality of the collaboration
• impressive development pace while maintaining the highest quality requirements
• the development efforts have been wisely evaluated and the final costs are on track with the initial estimates.

As a CTO working in the software development field for more than two decades, I can confidently say that I strongly recommend Callstack for any development project related to React Native.

Are there any areas for improvement or something they could have done differently?

Improve development efforts estimates for the automated tests implementation.