From scraping chaos to analytics: finally a stable hourly pipeline

From scraping chaos to analytics: finally a stable hourly pipeline

Hit a milestone this week with my web scraping infrastructure:

:backhand_index_pointing_right: it’s finally stable enough (hourly runs) that I can stop firefighting
:backhand_index_pointing_right: and start building analytics + visualizations to improve it


The last two weeks (real story)

Over the past couple of weeks, I’ve been constantly tweaking the architecture to balance load across:

  • the database

  • 3rd party services (especially Perplexity)

  • the scraper itself

Every time something improved, something else would get overloaded.

Replit did a great job suggesting fixes after each failure, but the pattern was clear:

:backhand_index_pointing_right: some part of the system would always become the bottleneck


The breakthrough

Instead of pushing harder, we dialed everything back and introduced gating:

  • limiting request rates

  • controlling concurrency

  • smoothing load across components

That got us to a point where:

:backhand_index_pointing_right: the pipeline could run on schedule without crashing


Then the direction flipped

Once things were stable, we could finally do the opposite:

:backhand_index_pointing_right: gradually increase load
:backhand_index_pointing_right: increase scraping throughput
:backhand_index_pointing_right: expand event discovery

…but without breaking stability


This is where analytics became essential

To scale safely, we needed visibility into the system.

The key question:

:backhand_index_pointing_right: Where do we have unused capacity?


Example visualization

The chart below shows scraping activity over time:

  • Blue = scheduled runs

  • Orange = pipeline / ad-hoc scraping

  • Red markers = error events (often tied to overload conditions like Perplexity limits)


What this reveals

Two really important things:

1. Whitespace (unused capacity)
There are clear gaps between spikes where:

  • the scraper is idle

  • services are underutilized

:backhand_index_pointing_right: This is where we can safely add more scraping


2. Overload signals
The red error markers tend to cluster around spikes in activity:

:backhand_index_pointing_right: especially when pushing Perplexity too hard

This gives us a visual way to:

  • detect rate limits

  • tune concurrency

  • avoid cascading failures


What I’m building now

Using these visuals to guide:

  • where to increase load

  • where to back off

  • how to balance across services

  • how to maximize event discovery without errors


Why this feels like a turning point

Before:

  • reactive

  • constant failures

  • unclear bottlenecks

Now:

  • controlled

  • observable

  • tunable


My takeaway

You don’t really “have” a data pipeline until:

:backhand_index_pointing_right: it’s stable enough to push harder safely
:backhand_index_pointing_right: and observable enough to know where to push


Curious how others approach this phase

  • How do you detect unused capacity in distributed systems?

  • Any good ways to visualize rate limits / third-party constraints?

  • Do you scale gradually or in larger steps?

Feels like this is where the real optimization work begins.

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In my mind I see you without the suit jacket covered in component dust, and revving the gas pedal of a car just throttling it lol

Yelling at it back and forth lol

Sounds like a fun scraping system…

Mind if I ask what you are using it for?

Edit: I’m having great talks with @mikeamancuso about his pipeline, as according to him, he’s scaling pretty hard right now, and from what I understand is doing some cool stuff. The two of you might want to consider connecting with each other at some point.

Just saying!

I approach development in Replit differently depending on the project. For my main application, I put a strong emphasis on solid architecture and future scale.

I start by ideating and iterating until I’m genuinely happy with the design. Once that’s done, I run the changes through our full CI pipeline to ensure everything passes tests, meets our code quality standards, and survives static analysis. Finally, I feed the code into a “distinguished engineer” prompt (AI review) to catch any brittle patterns and get advice on how we could scale the feature to handle ~1,000 concurrent users if needed.

I’m aware this process is probably a bit overkill for most Replit projects, but at this stage it only adds a couple of hours per feature. The payoff is huge: I ship with a lot more confidence that we’ll be in good shape as the app grows.

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@mikeamancuso

Roman aqueducts Were considered “Overkill” Too
Roman senators said it was excessive. Wells worked. Rivers worked. Why carve stone infrastructure across 90 miles of mountain terrain just to move water?
Same reason you build the pipeline properly the first time.
The aqueduct wasn’t solving thirst. It was enabling everything that depended on water at scale bathhouses, sewage, mills, a city of a million people that couldn’t function any other way. The overkill was the point. They were building for a Rome they were still growing into.

A CLI pipeline gets the same pushback. Just hard-code it. Just do it manually, it’s a one-time thing. Then the one-time thing runs every day for four years and the pipeline is the only reason nobody’s touched it since. You forget it’s even there, which is exactly how it’s supposed to work.

Each command does one job. Data flows one direction. The segments don’t know about each other and they don’t need to. That’s not a technical constraint, that’s a philosophy. The Romans figured it out in stone and mortar before we figured it out in bash.

They eventually built eleven aqueducts for one city, intentionally overlapping. Not because they ran out of ideas. Because the engineers understood something the senators didn’t: redundancy at scale isn’t paranoia, it’s just good thinking dressed up in expensive clothes.

Build for the data volume that isn’t there yet. The water will come.​​​​​​​​​​​​​​​​ The vibes will flow :wink:

This is a nice analogy seeing as I’m currently staying in Morgex in the Aosta valley only a few miles away from a Roman Terme. There’s also an aqueduct a little further down the valley. Lots of water in the Italian Alps right now as the snow starts to melt. LocalMusicX.com is a website information aggregator model. In our current use-case it’s discovering local music events in online calendars and publishing links to them in one place in case you want to go listen to some music tonight wherever in the world you happen to be. From an architectural point of view the application and the data pipeline are highly distributable, even down to each city. So we’ll be scraping cities more and more independently and parallel as we scale. This is documented in our “future features” and I expect Replit will be building it for us by the end of this quarter’s LiftedViz.com Marketing Analytics Internship program. Currently we’re scraping 70 curated cities twice a month along with any just-in-time new cities triggered by a user music event search with a very modest scraping cost per city.

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This is 100% unrelated.

You need to take pictures of said

And the

Just to share one loser on the internet who really gets off on that kind of thing lol One thing I will have to say about the engineering of their day (Peak Rome).

There’s a solid case (in the civil engineering world) for it being done too well.

Meaning:

1.) What was that formula for the cement y’all used? Cause dang. lol

2.) It’s outlived the intended time span. Cool but hard to take down, maintain, remove, replace. We put a life span on these things for a reason I suppose lol

Either way super cool.

As for the music app you got going on. That’s super cool. I listen to everything. You’ll notice I love adding music to everything. Love the concept.

In terms of developing:

1.) Are you saying right now your scraping engine basically a.) runs the scrape via google search → b.) catalogs → c.) organizes → d.) produces your intended outcome? (Very over simplified I know)

2.) What’s your traffic like?

3.) How has your group considered sustainability, or do you have plans to monetize?

4.) How big is your team?

Our scraping currently is pretty evolved after 5 months of trial and error. It uses Perplexity, Google Places, headless browsing, Google custom search and other services and APIs. This started as a no-code AI test project for our LiftedViz.com analytics internship program and now we have about 1000 hours and $5000 in Replit Agent and managed services into it. This Spring quarter we’ve got 3 new interns who will be focusing on using AI to do marketing and marketing analytics for the product launch.

John F Bremer Jr

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Congratulations, I’ve been seeing you post your journey. I hope you continue to do so.

I’m rooting for you. I wish you and your team success.