Building in public
The Erebos Lab Build Log
A year of shipping a studio of apps in the open — the bugs, the bad architecture calls, the metrics that read zero, and the honest lessons behind them. 365 posts across 12 months, written as @caelum0x42.
Month 1: The Machine That Builds the Apps
the studio itself. How one person runs a monorepo, a multi-agent build loop, and a shared core without drowning.
Day 1–30 · 30 postsMonth 2: Aether: Building a Wallet I'd Actually Trust
self-custody engineering. Keys, cost-basis P&L, RBF, curve-only pricing, the DeFi knowledge graph — and the paranoia of holding someone's money.
Day 31–60 · 30 postsMonth 3: Verification Is the Product
not getting fooled. When an agent writes the code and grades its own homework, the only thing between you and a green-checkmark disaster is a gate
Day 61–90 · 30 postsMonth 4: Cipher & the Retention Loop
a daily code-breaking game as a distribution experiment. Habit design, shareable results, generating puzzles legally, and why retention is harder
Day 91–120 · 30 postsMonth 5: The App Store Gauntlet
the craft between "works on my simulator" and "a stranger installed it." Privacy manifests, account deletion, Sign in with Apple, RevenueCat wiring
Day 121–150 · 30 postsMonth 6: Huddle: Real-Time Is Hard
self-hosted team chat on Matrix + LiveKit. Federated messaging, 3-level notifications, read receipts, screenshare, and the distributed-systems
Day 151–175 · 25 postsMonth 7: Knowledge Graphs: Model the Relationships
the shared idea under CalDesk's "healthier swaps" and Aether's DeFi graph. Ontology design, entity resolution, GraphRAG, and why the questions worth
Day 176–200 · 25 postsMonth 8: Making It Pay
monetization plumbing. RevenueCat entitlements, AdMob placement, paywall design, free-trial psychology, and the bracketed post I most want to earn
Day 201–225 · 25 postsMonth 9: Distribution Is the Actual Boss
the fight I dodged for 8 months. 0 users, landing pages, SEO, launches, the cold-start problem, and the humbling truth that shipping was the easy 20%.
Day 226–250 · 25 postsMonth 10: Where the Data Lives
offline-first vs cloud-first, the decision that shapes every syncing app. Echo's cloud-synced voice journal, Calc+'s local vault, conflict
Day 251–275 · 25 postsMonth 11: Infinite Content, Zero Theft
procedural and generative content done legally. The engine behind Cipher's puzzles and Vertex's levels — compute it or compose it originally, never
Day 276–300 · 25 postsMonth 12: The Honest Ledger
the year-in-review. What shipped, what died, the real numbers, the hard lessons, and what's next. No spin — the truest post is the hardest one. (65
Day 301–365 · 65 postsFollow along
New notes land as the build continues. Follow the day-to-day on X: @caelum0x42 — or [email protected] for anything else.