Scalable Architecture Code Optimization

My production platform has grown rapidly and the cracks are starting to show. It was built over time in Python, Node .js, JavaScript and a legacy PHP layer that still serves parts of the front end (HTML/CSS). We are in the maintenance phase, yet demand keeps climbing, so scalability is now the priority.

What I need is a seasoned software architect who can dive into the existing codebase, profile real-world traffic, and refactor or redesign the pieces that limit horizontal growth. The database layer is holding up for now; the bottlenecks are mostly in application code—tight loops, blocking calls, duplicated logic and a few monolith-style services that should be broken out or made asynchronous. Experience with high-throughput data processing, machine-learning pipelines and load-aware API design will be valuable because those paths process the bulk of our traffic.

Deliverables
• Architecture review document that pinpoints scalability risks and explains proposed fixes
• Refactored or modularized code (Python / Node .js / PHP where relevant) with clear comments and test coverage
• A migration or rollout plan that lets us deploy improvements without downtime