We offer 99.9% uptime guarantee by default. This can be extended with contracts and SLA. Our uptime page is available here
Our reverse geocoding requests typically take 50-100ms to process. The latency between your server and our endpoints is another variable the affects the response time. We can improve response times with dedicated instances, priority access, and custom sub-domains.
Please write to us via our contact page or email us at hello@locationiq.com with your requirements and we'll make it happen.