code review

codereview.md

config

• ensure config is loaded/tested in correct env

arithmetic/math

• check for divide by zero
• is integer division/rounding accounted for?
• what happens if inputs are very small/very large? or negative?
• what happens if results are negative (even though this "should never happen")
• integer overlow (in languages where matters)
• catastrohpic cancellation and other floating point concerns

db

• is a transaction necessary? can races be handled without a transaction?

background jobs

• can it be idempotent?
• do other jobs depend on this completing in a certain amount of time, or order?
• if we change this job, will already-enqueued things fail because they're expecting different params?

general

• make assumptions explicit -- what happens when things that should never happen happen?

strings

• handling unicode correctly?
• is db column large enough to store it?
• can it fit into UI?
• do you need to strip whitespace?

naming

• possible collision with language or framework, e.g. type columns could conflict with rails

HTTP endpoints

• are params sanitized?
• will params be shown to a user ever?
• what if we receive two simultaneous requests from the same user?

data from the API

• validate it as it enters the system?
• if we are storing it, how often will it need to be refreshed?
• rate limiting
• errors and retrying
• tracking failures

time

• can it happen in the past? should it happen in the past?

remote API requests

• will we hit a rate limit?
• what happens if the request succeeds but we never get a response due to network error?