John Jayasankar
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Labs

Instruments I shipped. Independent products, built end-to-end.

Consumer tools, a live football command center, and a native macOS app, each designed, built, and shipped live. Separate from the day job. No demos. These four have case studies; all eight are on Labs.

Visit Labs (opens in a new tab)See them on Work

01 / Consumer

RideLens

Every ride, one comparison.

Live roads. Real rate cards. Uber, Lyft, Empower, and Curb ranked before you open four apps and guess.

  • Map the trip once on live roads, then line up four providers side by side
  • Rank the same quotes by Price, Soonest, or Value
  • Estimates move with traffic, time of day, hotspots, and weather
  • 4providers, one board
  • 3ways to rank a trip
  • Honestranges stay ranges
Read the case studyOpen RideLens (opens in a new tab)
Illustrative: fare and wait traded off. Ranges stay ranges.Illustrative quote types, not live fares · the final fare is always confirmed in the provider app

02 / Native

Daylight

Your screen, through the day.

Warmth and brightness on a schedule you set: gradual, offline, and honest about what it is doing and why.

  • Shift warmth and brightness gradually on a schedule, or follow the sun
  • Decide every control on one printed, six-layer ladder
  • Read back after every write, and say so when another app took over
  • 6layers, one fixed order
  • 3levels of certainty
  • 263tests, no dependencies
Read the case studyOpen Daylight (opens in a new tab)
Asked, accepted, confirmed: an API returning success is not evidence the display changed.Schematic · step values from the Balanced preset · the sentence is one the app writes

03 / Consumer

RailDrop

Know when your train gets cheaper.

Book the trip. Watch every bookable Amtrak option across your window. One email when a listed fare actually drops.

  • Watch every bookable rail option across the day before, the day, and the day after
  • Scan immediately, then again morning, afternoon, and evening
  • One email when a listed fare beats what you paid
  • ±1 daydefault watch window
  • 1 emailonly when it improves
  • 0invented prices
Read the case studyOpen RailDrop (opens in a new tab)
Illustrative: one email when a listed fare beats what you paid. Confirm on Amtrak.Sample board from RailDrop’s own site · listed fares · confirm on Amtrak

04 / Live data

Gridiron

Every game. Every drive. One view.

A live NFL and college football command center: a 3D field for every game, with the reported ball spot, win probability, and odds beside it.

  • Follow every live NFL and college game, each on its own 3D field
  • Draw only reported spots: the ball, the line of scrimmage, the line to gain
  • Put ESPN win probability, DraftKings lines, and Kalshi prices beside the score
  • 3sources, each named
  • 0guessed ball spots
  • 669unit and integration tests
Read the case studyOpen Gridiron (opens in a new tab)
A 5-yard touchdown run, announced once, and ESPN’s model moves ARI +5 on the play.Captured real games from Gridiron’s NFL Week 1 replay · figures as ESPN, DraftKings, and Kalshi reported them · not betting advice

Each figure here is counted from the product’s own repository, or dated where it cannot be counted. Last checked 25 September 2026.

What they share

One discipline, four ways. Honest about what they know.

Each draws a hard line between what it knows and what it would be tempting to guess.

  • RideLens · Consumer

    Ranges stay ranges.

    When a fare is a range, both ends stay on the board. RideLens never invents a midpoint to look decisive.

  • Daylight · Native

    Success is not evidence.

    Daylight separates what it asked for, what macOS accepted, and what it could read back and confirm.

  • RailDrop · Consumer

    Never an invented price.

    If the live board is down, RailDrop says so. It never guesses a fare, a change fee, or an itinerary.

  • Gridiron · Live data

    Reported, never guessed.

    Every spot, clock, and chance comes from a source that reported it. A missing ball spot says so; it is never guessed to midfield.

labs.johnjayasankar.com

Every build lives on Labs.

The Labs site keeps the whole bench in one place, each product one click from live.Visit Labs (opens in a new tab)

j / k products · Enter opens the case · 1-4 phases · ⌘K jump