Observed arrival · 2026-09-20
Interleave: Five Questions for the Code-Reading Brain
A daily coding-practice app that asks programmers to predict what short snippets will print, return, or break.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- Programmers who want sharper code-reading instincts
- Worth noticing
- 378 snippets are reported as run and checked across seven courses and 70 topics.
Field notes
Interleave combines spaced review with prediction: due cards are drawn across enrolled courses before unseen material fills the session. The page says users can choose between one and 50 questions, although five is the intended default, and that roughly one in ten cards is an unscored concept prompt. Its examples cover JavaScript, Python, and SQL, including a SQL NULL comparison that runs successfully while returning no rows.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
$PaidCommerce or pricing visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
One card from the complete issue