BUILDING SINCE 2015 · NOT REVIEWED BY ANTOINE
Antoine
van der Lee
“Founder of SwiftLee, Indie Dev behind RocketSim”in their words · github.com
almost $100K ARR
RocketSim revenue
stated · Mar 2026almost $25K
From Side Project to Going Indie, total so far
stated · Dec 202410
products
2015
building since
Career
Every main product, who ran it, and when it changed hands.
Swift Concurrency Course2025 →
NOW
From Side Project to Going Indie2024 →
NOW
SwiftLee Weekly2020 →
NOW
RocketSim2020 →
NOW
SwiftLee2015 →
NOW
Side projects5
201520172019202120232025
Antoine runs ita new owner runs itsold, with the stated priceshut downside project
RocketSimRUNNINGsince Jan 2020
$4,512
MRR
Jan 2024 · old
almost $100K
ARR
Mar 2026
Figures Antoine stated, each measuring something different. We don’t draw a line between them.
The journey
RocketSim MRR $80 (2022) to $4,512 (2024); went indie in 2024
Milestones
almost $100K
ARR · RocketSim
Mar 2026 · stated
almost $25K
total · From Side Project to Going Indie
Dec 2024 · stated
$4,512
MRR · RocketSim
Jan 2024 · old
$69
MRR · Stock Analyzer
Dec 2022 · old
Latest
Mar 2026On RevenueCat's Launched podcast, with Charlie Chapman
Dec 2025Swift Concurrency Course: Completed by over a thousand engineers
Sep 2025On Dev Conversations #14, Swift Toolkit
Mar 2025Launched Swift Concurrency Course
Dec 2024RocketSim: RocketSim for Teams, the business version, first went live
How sure are we?
9 verified by someone other than Antoine78 stated by Antoine in public9 outdated, older than our limits
Read on 11 Oct 2026 · more data coming