TWIL July 10th 2026

• Writing tests for a migration from qs to URLSearchParams takes way longer than the actual changes
  • But probably saves even longer than that in future emergency debugging
• Old browsers used to accept ; as a separator in query strings rather than ?
• Apparently asking the user for their login info so you can reproduce the issue is a valid solution
  • Admittedly their account is entirely unusable and we have no idea what's happening after weeks
• Microservices work much better if they're actually separate; i.e. changing a user's unconfirmed email doesn't require manually propagating that change outside the user service
• Aaaand the long running support ticket my team was flummoxed by was also caused by the user service/main app separation
  • A user created their account with an @gmail address
  • Sometime later they created another account
    • That account was somehow created on the user service but not propagated to the main app
  • They changed the original account's email to @gmai (no 'l')
    • That was also not propagated to the main app
  • They changed the new account's email to the email of the original account (with @gmail)
  • They tried logging in to their new account to access one of our other apps; that app crashed because it tried to get data from the main app for a user the main app doesn't think exists
  • They contact us; a week+ of confusion ensues because the uid of the user we were provided with was the original account, which on the main service still had the @gmail address despite it being @gmai on the user service
    • We had no idea the other account existed at the start, despite it being the one the user was logging into
    • So we initially thought the user service was issuing tokens for some other random user
• Would've been much easier to solve if we had visibility into emails on the user service; they're in the admin UI on the main app but for the actual user service we can't even query them (normally)
  • luckily I still have my old Platform team access, so I could query the DB directly and see the @gmail/@gmai difference
• Sometimes it's good to clarify 'common knowledge' you're not 100% sure of the accuracy of
  • So you can avoid causing issues promising something that's only an internal SLO
• Another one for the 'annoyingly unstylable inputs' collection; you can't manually position a placeholder by styling the placeholder
  • It's just positioned with the input's padding, which is annoying if your placeholder starts with a full-width Japanese bracket (「)

Links

• Time-based background colour transitions with Temporal and CSS color-mix - Sophie Koonin

Cool background-color transitions with the new Temporal API.

• Proxy & Reflect - Mat Marquis

I now know slightly more about how mobx (probably) works, which is still considerably less than I should for something Vault relies on so heavily.