Hiring Experienced in Quality and Performance

I am in need of a VFX Artist who is experienced in creating high quality effects, BUT is also very experienced in OPTIMIZING for performance.

Project I'm currently developing a Firefighter game where players extinguish burning buildings.

What's your job? I need you to create just 2-3 particle effects for now (If I need more I will let you know, and will increase your pay depending on the scope)

The current VFX needed are:

My current fire system uses a large number of particle emitters which takes a massive toll on performance, and I'm looking for someone who can either:

Design visually impressive yet highly optimized particle effects,

OR

Suggest better VFX techniques/workflows that significantly reduce performance cost while maintaining quality.