Contract board
scheduledTier 6

Zigzag Timetables

Client: Coastline Bus CompanyIntercity coaches · Accra to Takoradi

Coastline Bus Company depot, Kaneshie, Accra · Quiet, deliberate

Coastline Bus Company runs coaches between Accra and Takoradi. A contractor 'optimised' the timetable export, and now it comes out in zigzag rows and shuffled columns. Passengers keep missing buses.

Who you'll work with

Ada MensahYour lead

Engineering Lead

Dry, warm underneath, short sentences. Notices how you did. Never gushes.

Mr. Kobina Mensah

Route Planner, Coastline Bus

Precise, patient, owns three watches.

Tunde Bakare

Senior Developer

Friendly rival. Competitive banter, always generous in the end.

The client's system

Zigzag and grid

Rail fence with growing row counts, keyword columnar transposition, and the contractor's pipeline that hides a transposition inside encodings.

Rail fenceColumnar transpositionScrambled pipeline

6 tickets in the sequence · every developer gets unique keys and tests · the rules come out in the tickets

Opens in

…
Pay / ticket
40–80
Band
2,500+
Scored tickets
6
Your time
120h

0 devs on this contract

Performance bonus · top 10

+220 gems to 1st

  1. #1+220
  2. #2+150
  3. #3+110
  4. #4+44
  5. #5+44
  6. #6–10+44 each

Ship 3+ tickets for a +15 completion bonus.

The shortlist stays hidden until wrap-up. Only the first 6 tickets count.