Today wounded Bitcoin exchange Bitstamp resumed operations and moved to moved infrastructure into San Francisco. In a letter posted on the exchanges's website CEO Nejc Kodrič describes the new Bitstamp is build in a way that seems a bit contradictory:

The Bitstamp systems are running on 100% new hardware deployed from a completely secure backup of our code and data.

and

Bitstamp is now running on Amazon’s world-class AWS cloud infrastructure, architected to be one of the most secure and reliable cloud computing environments available.

These don't seem to be reconcilable points as dedicated hardware and Amazon's hosted web services are different things. Nejc also emphasizes

On January 4th, some of Bitstamp’s operational wallets were compromised, resulting in a loss of less than 19,000 BTC

Even through the difference between 19,000 BTC and the actual 18,867.62695929 BTC lost is a rounding error given the scale of the incredible numbers involved in this loss. Nejc's full message is online here and preserved below for posterity:

Dear Bitstamp customers,

We are happy to announce that we are back open for business with a newly redeployed website and backend systems that are safer and more secure than ever. Thank you for your patience during our temporary disruption of services this week. We’d like to share with our customers and community an update on the events of this week.
What happened?

On January 4th, some of Bitstamp’s operational wallets were compromised, resulting in a loss of less than 19,000 BTC. This breach represents a small fraction of Bitstamp’s total bitcoin reserves, the overwhelming majority of which are held in secure offline cold storage systems. We can assure customers that any bitcoins held with us prior to temporary suspension of services on January 5th at 9am UTC are completely safe and will be fully honored.

Upon learning of the breach, we immediately notified all customers that they should no longer make deposits to previously issued bitcoin deposit addresses. As an additional security measure, we suspended our systems to fully investigate the incident and actively engage with law enforcement officials.

Why did Bitstamp go offline for a few days?

We took the decision to rebuild our systems from the ground up from a secure backup for a few reasons. By redeploying our system from a secure backup onto entirely new hardware, we were able to preserve the evidence for a full forensic investigation of the crime. We have also taken this time to implement a number of new security measures and protocols so that customers can resume using Bitstamp with full confidence and trust. While this decision means we have not been able to provide you with services for a number of days, we feel this extra measure of precaution was in the best interest of our customers.

What’s new?

Our team has been working day and night to rebuild and restore security to the Bitstamp site so customers can resume transacting with us quickly, safely, and confidently. Bitstamp is now fully operational with a number of key improvements:

Multi-sig
* With the integration of BitGo multi-sig technology, Bitstamp is now the first and only major bitcoin exchange to incorporate the industry's best security practices available today.

Completely new hardware infrastructure
* The Bitstamp systems are running on 100% new hardware deployed from a completely secure backup of our code and data.

Amazon Web Services
* Bitstamp is now running on Amazon’s world-class AWS cloud infrastructure, architected to be one of the most secure and reliable cloud computing environments available.

Commission-free trading
* As a note of thanks to our loyal customers, all transactions conducted on Bitstamp through the end of the North American Bitcoin Conference — January 17th (at 11:59pm UTC) — will be commission-free.

We appreciate your patience and understanding during this disruption of services. Since 2011, we’ve worked hard to be one of the largest and most trusted bitcoin exchanges in the world. While this is a time of challenge for our company, we expect to emerge from this experience having set an even higher bar than before for trust and confidence in our services.

On a personal note, I’d like to thank the incredible teams at Bitstamp and at our lead investor Pantera Capital who have worked around-the-clock from multiple time zones in the last few days. I’m incredibly proud of the herculean work of this extended team, and grateful to the phenomenal show of support from customers, friends, and partners in the bitcoin community.

We look forward to serving you!

For additional information, please refer to our customer FAQ or contact our support team at support@bitstamp.net.

Thank you,
Nejc Kodrič
CEO of Bitstamp