Stock Trading Web App Upgrade

I have a live, fully functional stock-trading web app that now needs a top-to-bottom refresh. The scope is threefold:

1) User interface
The dashboard layout, interactive charts and graphs, and overall navigation must become cleaner, faster and more intuitive, without losing our current branding. Responsive behaviour on desktop and mobile is essential.

2) Trading algorithms and strategies
I want the existing strategies retained but enhanced. Please refactor the code, add meaningful logging, tighten risk controls and deliver measurable speed-ups in execution. Any quick-win quantitative improvements are welcome, provided the core logic remains recognisable.

3) Backend performance & scalability
Under load the app slows down, so database queries, API endpoints and overall architecture need profiling and optimisation. Prepare the stack for horizontal scaling—caching, load-balancing or containerisation as appropriate.

Deliverables
• Implemented UI overhaul that matches approved mock-ups
• Refactored algorithm module with benchmark report showing improved latency and accuracy
• Backend performance report plus deployment scripts that prove scalability in load-tests

All work will be pushed to our private Git repository as incremental pull requests, each with clear commit messages and unit tests. In your proposal, outline the tools or frameworks you prefer and your estimated timeline so we can align on approach quickly.