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Your lockfile's dev/prod split won't tell you which licenses your app must credit
A record of classifying every dependency in a production project to decide what belongs on an app's license screen, and where the copyleft findings and the actual shipped artifact turned out to disagree.
Four Countries, Not the World: Checking Which of My Six Apps the September 30 Deadline Actually Touches
Android developer verification goes live on September 30, 2026 in Brazil, Indonesia, Singapore, and Thailand. Here's how to decide from your own install data whether that date is urgent for you, and what actually blocks indie developers.
Switching to Signed URLs Killed My Image Cache — Decoupling expo-image Keys from the URL
Signed URLs rewrite their query string on every expiry, so a URL-keyed cache never hits. Here is how to pin the key with source.cacheKey, what the cache read and write APIs actually return, and what changed when I re-ran the measurements.
Measuring Hermes Bytecode Delta Updates: One Added Module Cost 29x More Than One Changed Line
I measured OTA delta sizes against a 2.4MB Hermes bytecode bundle. Changing one line cost 2,104 bytes; adding one module cost 61,197. The widely repeated advice about stable module IDs turned out to matter least.
The 429s Kept Coming After Recovery: Measuring Retry Jitter Across 2,000 Clients
My backend came back but the 429s did not stop. I rebuilt the scenario in a 2,000-client discrete simulator and measured what plain exponential backoff, delay caps, 10% jitter, and honoring Retry-After cost in seconds — then reran everything with server capacity that degrades under load.
Cutting MCP Tools Didn't Make Anything Lighter — 2,377 Bytes of Definitions vs 110,298 Bytes of Response
I wrote a minimal MCP server for a wallpaper catalog and measured the byte cost of tool definitions against the byte cost of responses. Here is which side actually matters, and the real reason to merge tools.
Deciding overlay text legibility at ingest time instead of on device — four metrics measured side by side
Moving the question of whether text stays readable over a wallpaper out of the device and into the content pipeline. Four candidate metrics measured across 240 images, including what downscaled judging actually computes.
A JSON File 19% Smaller That Ships Only 3% Smaller — Measuring Catalog Payloads Against gzip
Five payload formats measured on a 20,000-item wallpaper catalog. Key shortening saves just 3.2% after gzip, while a columnar layout cuts 26.8%. Real numbers for Brotli, paging, and JSON.parse time.
Exactly 20 Characters, Still Rejected: Putting Character Counting Behind One Boundary
Emoji and combining marks make your client and your server disagree about length. I measured four counting methods on Node v22 and found 75.6% of naive truncations split a grapheme and 36.1% produced replacement characters over UTF-8. Here is the shared-module design that fixed it.
When 1.10.0 Gets Locked Out: Measuring Four Version Comparison Approaches for Forced Updates
A remote-config gate for minimum supported version, rebuilt after measuring four version comparison approaches. Includes the cases where localeCompare reports equality, the fail-open boundary, and the incident caused by gating on a build still in review.
When Two-Character Queries Silently Return Nothing: Measuring Japanese Search Indexes in an Expo App
SQLite FTS5's trigram tokenizer returns zero rows for Japanese queries shorter than three characters, without raising anything. I benchmarked linear scan, a bigram inverted index, and FTS5 over a 20,000-item catalog to find the real threshold.
Every Experiment Kept Landing on the Same Devices: Hash Choice and Salt Position, Measured Across a Million IDs
On-device experiment assignment looked fine in isolation, then collapsed the moment two experiments ran side by side. Here is what one million IDs revealed about four hash functions, why the culprit was the concatenation order rather than hash quality, and the implementation I settled on, with the measured numbers.