

John McEvoy
71 posts

@johnmarkerpen
Indie iOS developer. Founder and builder of @trymomego










what separates juniors from real fullstack devs → • safe db migrations • cache invalidation strategies • rate limits & abuse prevention • background jobs with retries + idempotency • file uploads at scale (multipart, presigned urls) • observability (logs, metrics, traces) • feature flags & staged rollouts • handling concurrency & race conditions • blue-green / canary deploys • postmortems & rollback discipline



@JordanMorgan10 What are you talking about, it’s there!










@levelsio How does it scale though?




@levelsio Started off with a $5 VPS on DO in 2013, now running 20 dedicated servers on OVH/Hetzner behind a geo load balancer from Cloudflare. All automated, all optimised to pipe as many requests as possible with the lowest latency. Started small, made mistakes and grew organically.

