employed.

ace the interview.
one puzzle at a time.

duolingo-style daily drills for google, meta & quant trading interviews. coding + quant tracks. streaks, xp, elo. get hired.

download on theApp Store

📱mobile only. no desktop version.

9:41
good morning,
lsoffice.
coding
quant
today's challenge
⚡ daily challenge
difficulty ramp · stay sharp
1.1× xp
7
day streak
level 4
analyst
620 / 900 xp
rank
analyst
🔥 7d streak
top skills
big-o1280
probability1145
debug1060

two tracks.

train for the interview
you're actually facing.

coding

google & meta prep

leetcode-style intuition, no typing required

builds the fast mental models that get you through google/meta screens

  • big-o analysis
  • debug the code
  • predict output
  • data structure matching
  • pattern identification
  • system design
  • sql
  • fill the blank
  • order the steps
quant / trading

trading floor prep

mental math, probability & logic for buy-side interviews

drills the fast-twitch intuition that trading floor screens demand

  • mental math
  • probability
  • expected value
  • sequences
  • logic puzzles
  • brain teasers
  • market intuition
  • speed approximation

how it works.

five minutes.
every day.

9:41
good morning,
lsoffice.
coding
quant
today's challenge
⚡ daily challenge
difficulty ramp · stay sharp
1.1× xp
7
day streak
level 4
analyst
620 / 900 xp
rank
analyst
🔥 7d streak
top skills
big-o1280
probability1145
debug1060
×
⚡ daily challenge
2/7
+8 xp
complexitydifficulty 3
what is the time complexity of binary search on a sorted array of n elements?
O(1)
O(log n)
O(n)
O(n log n)
practice
choose a mode and drill your weak spots.
daily challenge
5 min · difficulty ramp
🔥
quickfire blitz
10–15s · speed drill
pro
🧠
deep think
60–90s · interview sim
pro
🎯
precision
30s · targets weak spots
pro
💀
boss round
45–60s · difficulty 5 only
pro
session complete
nice run. 🎉
84%accuracy
+42 xp
🔥 7 day streak
6/7
correct
4m 12s
time
return home →

five game modes.

never get bored.
never plateau.

free

daily challenge

5 min · difficulty ramp · stay sharp

5–9 questions20–45s each

quick warm-ups first, then a tough finisher. pace yourself.

pro
🔥

quickfire blitz

10–15s per question · speed drill · easy wins

8–10 questions10–15s each

rapid-fire easy-to-mid questions. trust your gut and keep moving.

pro
🧠

deep think

60–90s per question · interview simulation · no shortcuts

4–6 questions60–90s each

fewer questions, much harder. reason it all the way through.

pro
🎯

precision

30s per question · targets your weak spots · accuracy focus

7–9 questions25–35s each

mid-to-hard questions aimed at your weak spots. accuracy beats speed.

pro
💀

boss round

45–60s · difficulty 5 only · elite mode

5–7 questions45–60s each

every question is elite-level. no warm-ups. no mercy.

your journey.

start as an intern.
become the citadel final boss.

rank titles

lv 1intern
lv 3analyst
lv 5junior quant
lv 8researcher
lv 10hft engineer
lv 15principal
lv 20wizard
lv 25citadel final boss

streak flames

1–2 days
no multiplier
3+ days
blue flame
7+ days
1.25× xp · gold flame
30+ days
1.5× xp · electric

xp multipliers

4+ day streak1.1× xp
8+ day streak1.25× xp
15+ day streak1.5× xp

elo skill ratings

every puzzle type has its own elo starting at 1000. answer correctly to climb. tracked separately for coding and quant.

elite1500+
strong1250–1499
solid1050–1249
developing850–1049
beginner< 850

friends leaderboard.

prep is better
with rivals.

invite friends, compete on xp, compare your elo ratings skill by skill. no anonymous strangers, just the people you actually want to beat.

  • friends-only leaderboard, not global noise
  • head-to-head elo comparison per skill type
  • share your session score to instagram stories
  • invite via link: friends join your leaderboard directly
coding · all time xpweek 1
🏆
lsoffice.
analyst · lv 4
1,240 xp
2
mark zuckerberg
hft engineer · lv 11
890 xp
3
jeffrey epstein
intern · lv 1
120 xp

tap a friend to compare elo ratings

pricing.

7 days free.
then keep the streak alive.

no free tier. you get a 7-day trial with 1 session per day. no card needed to start.

cancel anytime · billed through apple · cheaper than your morning coffee ☕

base
1 daily challenge · streaks · xp
£2.99/week
£9.99/mo · £89.99/yr
7-day free trial
  • 1 daily challenge per day
  • streak tracking + xp + levels
  • friends leaderboard
  • progress syncs across devices
  • ×all 5 game modes
  • ×unlimited sessions
  • ×quant track
start free trial

£0.43/day after trial

best deal
bundle
base + pro: one price, everything
£4.99/week
£16.99/mo · £149.99/yr
most popular
  • 1 daily challenge per day
  • streak tracking + xp + levels
  • friends leaderboard
  • progress syncs across devices
  • all 5 game modes
  • unlimited daily sessions
  • pro-only elite puzzles
get the bundle

save £0.99/wk vs buying separately

pro upgrade
add-on on top of base
+£2.99/week
+£9.99/mo · +£89.99/yr
  • unlimited daily sessions
  • all 5 game modes
  • pro-only elite puzzles
  • streak freeze protection
  • ·requires base plan
upgrade to pro

save 23% on monthly · save £29.89/yr

quant track
probability · mental math · market intuition
£2.99/week
£9.99/mo · £89.99/yr
  • mental math & speed approximation
  • probability & expected value
  • market intuition & options greeks
  • brain teasers & logic puzzles
  • sequences, patterns & estimation
unlock quant

save 23% on monthly · save £29.89/yr

🧊
streak freeze
one-time consumable · protects your streak if you miss a day
£1.99 one-time

all prices in gbp · subscriptions managed via apple · cancel anytime in ios settings

employed.

your next interview
isn't far away.

five minutes a day is all it takes. start your streak today.

download on theApp Store

available on ios · no web version