What can we do to increase security and prevent Bitcointalk suffering something similar in future?
Why asking this question when Bitcointalk has been able to remain operational since over 15 years ago? Did you think there were no hackers that tried to take over this forum? You are an old member, you know this.
Theymos really tried letting this forum be where it is today.
Yes Theymos and team have done a great job and I'm sure they have really hardened their cyber posture since 2015. Btalk has some pretty serious bounties for finding flaws in the system so they are doing that too. What i do wonder is if there have been any external penetration tests done with remediation and patch work, I'm sure they have been all over it though.