What are pros and cons of Hackathons on implementing a DevOps culture? I am curious about the efficacy of using a "hackathon" to focus development early in a new project before moving a more formal DevOps process.  

Does letting things start out fast and loose to get things going hamper later efforts to add process?
If so, how does one weigh the benefits of building that early momentum vs. establishing a good DevOps process?
If the project is for a startup's minimum viable product or some other sort of sanity-check/proof of concept effort - hackathon before DevOps is often recommended - basically in the "fail-fast/fail cheap" lean startup strategy.

Some might recommend hackathon before DevOps in other situations as well, for time-to-market reasons. But if DevOps doesn't followup fast enough that initial market bridgehead can easily collapse. Possible reasons for that include:


that early momentum can be ephemeral - easily lost as soon as the DevOps process starts to be established ("it's too hard, it's slowing us down")
typically hackathons cause accumulation of technical debt. The cost of managing and eliminating it can outweighs the benefits of that early momentum.