# May 31th, 2016

## Agenda

1. Retrospective on last week:
	- What went well?
	- What was challenging?
	- What did you learn?


## What went well?

@robrix:

- As of this morning we’re pushing data to graphite.
- There's a 2 hour window of when data is pulled in to graphite.
- We have a much more thorough understanding of the shape of the SES problems.

@rewinfrey:
- Came away with a much more thorough understanding of SES.
- Pairing with Rob on the profiling issues.

@joshvera
- Exploring the current productions of tree-sitter output.
- Got an airbnb for the Mini-Summit.


## What was challenging?

@robrix:
- SES performance has been a problem. Briefly confused into thinking we had solved the problem. We’re profiling semantic-diff-tool and running the tests on semantic-diff. If we don’t clean semantic-diff-tool then it doesn’t know that semantic-diff has been rebuilt and it doesn’t try to relink it. Happens specifically when changing branches. 
- SES performance depends on O(n) cost function.

@rewinfrey:
- Heartbreaking to discover that a huge performance win was a bad build.
- Felt like it was hard to contribute to the deployment and build process.
- Do we have a fallback in place in case S3 fails?

@joshvera:
- Error productions from tree-sitter are difficult to debug and obscure diff summary output.
- Understanding and communicating how our deployment process works to other people. Maybe this means we need better documentation?


## What did you learn?

@robrix:
- Learning about parallelism because we have large asymptotic factors in SES.
- Developed a stronger intuition for why cost has to be linear with respect to the size of the diff tree.

@rewinfrey:
- Learned a lot about profiling in Haskell.
- Learned how to use Profiteur to visualize the space and time costs for a given computation.
- Trying to use the Eval monad to parallelize the Minimax algorithm.

@joshvera:
- Learned about designing CRISPR proteins that can be edited into bacteria to defend against viruses and plasmids.
- Read up on GHC's Core language in order to understand some of the optimizations GHC performs.


## Other Items

- Mini-Summit plans set for the week of June 20th.
- Rob on vacation starting Tuesday June 7th! :sunglasses: