Ask HN: Has AWS ever surprised you with a bill?

Posted by noway_bro on Sunday July 06, 2025 @08:30PM
from the ask-hn dept.

I’m validating a small tool that could’ve caught a $42k DynamoDB spike before it snowballed — within 10 minutes, via Slack alert.

Trying to talk to 10 devs or engineers who’ve been hit by unexpected AWS charges (Lambda loops, S3 egress, log retention, etc).

Not selling anything. Just want to understand:

- What caused it? - How you found out? - What you tried after? - Would a $15/mo tool with IaC cost-diff + Slack alerts have helped?

If that’s you (or your team), I’d love to hear from you.

( 13 comments | 4 points | on HN )

Re:Ask HN: Has AWS ever surprised you with a bill? by muzani on Sunday July 06, 2025 @10:33PM (#44486207)

Yeah, it's a meme at this point that if you're learning AWS, expect to be homeless because you left the EC2 on. Maybe not that bad, but I feel like most people have the logging to detect spikes etc, except those who don't know how to do logging.

[ Parent | on HN ]

Re:Ask HN: Has AWS ever surprised you with a bill? by scarface_74 on Monday July 07, 2025 @12:32AM (#44486777)

Funny enough, AWS has added recursive lambda call prevention within the last two years.

https://docs.aws.amazon.com/lambda/latest/dg/invocation-recu...

[ Parent | on HN ]

Re:Ask HN: Has AWS ever surprised you with a bill? by shiva0801 on Monday July 07, 2025 @07:40AM (#44489247)

Yep — we got hit with a ~$1.8k bill spike on AWS due to a Lambda function caught in a recursive loop during a staging deploy. It kept calling itself due to a misconfigured trigger — we didn’t catch it for ~6 hours because it wasn’t high-traffic, just persistent.

[ Parent | on HN ]

Re:Ask HN: Has AWS ever surprised you with a bill? by noway_bro on Monday July 07, 2025 @08:10AM (#44489517)

And $15/m would be interesting to not have this problem ever again? Is there anything else that would be cool to have with that?

[ Parent | on HN ]

Re:Ask HN: Has AWS ever surprised you with a bill? by codingdave on Monday July 07, 2025 @11:32AM (#44491417)

I would not pay anything for a tool to fix this because you can handle it yourself with logging, budgets, and various alerts. The people who are willing to pay for this would likely only pay for it for a few months, until they learn AWS enough to protect themselves from it on their own.

So while the road you are looking down has some validity, it is also a high-churn product idea that only holds value for people who are brand new to AWS. I'd be hesitant to dedicate much time to such a narrow market.

[ Parent | on HN ]

Re:Ask HN: Has AWS ever surprised you with a bill? by tom_m on Monday July 07, 2025 @09:36AM (#44490254)

No, only Datadog has done that to me.

[ Parent | on HN ]

Re:Ask HN: Has AWS ever surprised you with a bill? by idontwantthis on Monday July 07, 2025 @01:08PM (#44492413)

DynamoDB got me for a couple hundred in college after I used it for a hackathon. Fortunately support was kind to me and wiped it after I explained.

[ Parent | on HN ]

Re:Ask HN: Has AWS ever surprised you with a bill? by noway_bro on Monday July 07, 2025 @01:13PM (#44492475)

And $15/m would be interesting to not have this problem ever again? Is there anything else that would be cool to have with that?

[ Parent | on HN ]

Re:Ask HN: Has AWS ever surprised you with a bill? by idontwantthis on Monday July 07, 2025 @05:04PM (#44494657)

No that wouldn’t be worth it at all.

[ Parent | on HN ]

Re:Ask HN: Has AWS ever surprised you with a bill? by ActorNightly on Monday July 07, 2025 @02:12PM (#44493142)

Nope.

I personally don't use any AWS constructs, just reserve EC2s as needed and host everything myself.

[ Parent | on HN ]

Re:Ask HN: Has AWS ever surprised you with a bill? by graealex on Monday July 07, 2025 @02:23PM (#44493238)

"Not selling anything" is a wild take on "would you pay $15 per month".

[ Parent | on HN ]

Re:Ask HN: Has AWS ever surprised you with a bill? by noway_bro on Monday July 07, 2025 @02:26PM (#44493265)

I'm doing research, I literally don't have anything to sell

[ Parent | on HN ]

Re:Ask HN: Has AWS ever surprised you with a bill? by vijit-singh on Monday July 07, 2025 @03:31PM (#44493842)

hi there, this is a problem I have been thinking about a lot lately as a recent entrepreneur. I would love to chat more and collaborate, please feel free to mail me (email in profile). thank you.

[ Parent | on HN ]