How We Run Firecracker VMs Inside EC2 and Start Browsers in <1s

Re:How We Run Firecracker VMs Inside EC2 and Start Browsers ... by timojeajea on Wednesday June 17, 2026 @04:49PM (#48576681)

We run a screenshot API (ApiFlash) with Chromium packaged in an AWS Lambda container image instead of Firecracker on EC2. AWS Lambda gives you the isolation and autoscaling for free which is ideal for spiky stateless work like screenshots. I believe we get mostly the same benefits compared to browser-use solution but with a much much simpler architecture. The tradeoff is the AWS lambda cold starts, but in practice sequential AWS Lambda invocations actually reuse a hot function. As a result, with a large enough volume, spikes are smoothed and cold starts are not that frequent.

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Re:How We Run Firecracker VMs Inside EC2 and Start Browsers ... by Reformedot on Wednesday June 17, 2026 @05:07PM (#48576935)

Not all use cases require all the features that we built

Few issues we had with lambas: - Limited running time (15 min), we support up to 4 hours (we can run longer if needed) - Price - Lack of snapshotting mechanisms - Lack of low-level control over the running host

But yeah, lambda is way more than enough for most common use cases automating the web

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Re:How We Run Firecracker VMs Inside EC2 and Start Browsers ... by epolanski on Wednesday June 17, 2026 @05:41PM (#48577303)

Your solution sounds very expensive.

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Re:How We Run Firecracker VMs Inside EC2 and Start Browsers ... by timojeajea on Wednesday June 17, 2026 @05:58PM (#48577501)

From our production stats, a median screenshots capture is 5.7s. Browser-use bills per minute, not per millisecond like lambda does. As is, it's around 2x more expensive than Lambda for our use-case.

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Re:How We Run Firecracker VMs Inside EC2 and Start Browsers ... by Reformedot on Wednesday June 17, 2026 @06:48PM (#48578082)

Fair. We bill by minute cause our main use case is web automation. If you compare per minute, Lambdas are 4-6x more expensive than our solution

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Re:How We Run Firecracker VMs Inside EC2 and Start Browsers ... by y2244 on Thursday June 18, 2026 @03:35AM (#48582064)

Doesnt lambda use Firecracker under the hood?

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Re:How We Run Firecracker VMs Inside EC2 and Start Browsers ... by QGQBGdeZREunxLe on Thursday June 18, 2026 @09:45AM (#48585223)

Yes

https://aws.amazon.com/blogs/aws/firecracker-lightweight-vir...

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