A while back I started building a small tool to download TikTok videos without the watermark, mostly because I was annoyed at how clunky the existing options were. What started as a weekend script turned into something I've now been maintaining for a long time, and it taught me way more about backend reliability than any tutorial ever did.
I'm not going to pretend this was some clean, well-architected build from day one. It wasn't. The first version was basically one script calling one endpoint and praying it wouldn't time out. It worked fine until it didn't. The platform I was scraping from changes things often enough that you can't just build once and forget about it.
Why one server was never going to be enough
Somewhere around the time traffic started picking up, I noticed requests would randomly hang. Not fail, hang. Turns out hitting an external API from a single server gets you rate limited fast once you're past a certain volume, and there was no graceful way to know that was happening until users started complaining.
So I ended up spreading the load across multiple servers instead of relying on just one. If one gets flagged or slows down, requests fail over to another instead of just hanging forever.
I'll be honest, the failover logic isn't elegant. It's a fairly blunt "if this one fails or times out, try the next" setup. I keep meaning to rewrite it with something smarter (maybe a proper health-check + queue system) but it's been "good enough" for over a year now so it keeps getting deprioritized. If anyone's dealt with this at bigger scale I'd genuinely like to hear how you approached it.
Locking things down
Once you've got multiple pieces talking to each other internally, you realize pretty fast you can't just trust incoming requests blindly. I added request signing between the layers, so anything hitting the backend has to prove it actually came from the right place first.
Sounds like overkill for a "just download a video" tool until you get your first bot scanning your endpoints trying to skip the frontend entirely and hit things directly. Then it stops feeling like overkill.
The abuse problem nobody warns you about
Free tools attract abuse. Not in some dramatic way, just constant low-level scraping and automated hammering from bots trying to bulk-pull content. I ended up building out a proper tracking system for flagged IPs instead of a flat ban list, something that actually records why something got flagged and when, so I'm not just guessing later.
I also added a softer middle ground for borderline cases, a slowdown instead of an outright block. It's cut down on a lot of false-positive complaints from real users stuck on shared IPs (university networks, corporate VPNs, that kind of thing).
Some things are still slow and I know it
There's a specific link type on the platform I support that still takes an extra round trip internally before it can resolve. I've got a partial fix cached in the meantime, and I know the "proper" fix, I just haven't fully trusted it in production yet. Sometimes the correct fix takes longer to ship than the hacky one you already know works.
Where it's at now
Nothing here is groundbreaking, honestly. It's mostly just the accumulated result of things breaking in production and me patching them one at a time over months. If you're building anything that scrapes or proxies third-party APIs at real volume, the two things that mattered most to me were:
- Don't assume one server/IP will hold up under real traffic, even if it feels fine in testing
- Log more than you think you need to. Half my debugging time gets saved just because I logged why something failed instead of just a generic error
If you want to see the actual thing, it's live at tikvidly.com. Still working through a few rough edges on newer features.
Would love to hear if anyone else has dealt with similar rate-limit/abuse cat-and-mouse games on scraping-adjacent projects.
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