IPAL by ALCAD

The challenge

ALCAD had a legacy iOS app, written years earlier in Objective-C by an external provider. The VoIP stack relied on a third-party video-call SDK that routed traffic through external services, leading to critical issues, dependency on a vendor outside ALCAD's control, and compatibility problems with recent iOS versions. The situation put at risk the service delivered to clients in sensitive sectors such as healthcare. The team needed a senior iOS engineer capable of entering legacy code, diagnosing root causes and redesigning the most critical part of the product: the real-time video call against ALCAD's intercom hardware, eliminating the third-party SDK dependency.

The solution

AtalayaSoft assigned Francisco José García Navarro as a senior iOS engineer for a focused engagement to stabilize the product and modernize its architecture. The scope covered two fronts:

1. Video-call architecture refactor

As senior iOS reinforcement, Francisco redesigned and implemented the entire video-call stack 100% natively, in two layers:

• Media capture and playback with AVFoundation (Apple's framework for real-time audio and video capture, processing and playback), removing the commercial SDK dependency carried by the previous version.
• Video and audio stream transport through a native connection against ALCAD's own server, without going through external video-call services (Twilio, Agora, Sinch or equivalents).

The result is an architecture where both the media and its transport are handled within ALCAD's perimeter, integrating directly with their VoIP intercom system and the physical hardware installed in buildings.

2. Legacy code stabilization and modernization

In parallel, Francisco worked on the existing Objective-C base to:

• Resolve critical VoIP bugs affecting remote door entry and call quality.
• Update the app to support recent iOS versions and keep its App Store presence.
• Implement client-requested feature improvements without rewriting the full project.

Featured technical achievements

Zero third-party dependencies in the multimedia stack

Implementing both media capture/playback (with AVFoundation) and stream transport (against ALCAD's own server) without relying on external SDKs eliminated three risks at once: extra binary weight, vendor-forced SDK updates and dependency on an external service for a critical product feature. ALCAD gained full control of the video-call stack, with no external licenses, no third-party services on the media path, and an architecture aligned with Apple's platforms for the long term.

Continuity on production Objective-C code

Rather than proposing a full rewrite (with its cost, timeline and risk), Francisco worked within the existing codebase, modernizing only the critical piece. This pragmatic approach allowed ALCAD to keep the service running in production while the underlying issues were resolved.