Blog — page 25 of 38
Sandboxing AI-Agent 3D Rendering and Asset Pipelines in MicroVMs
Your agent writes a Blender script and something has to run it. Meanwhile the scene file it was handed can execute Python the moment it opens. Give that job a machine you can throw away.
Processing PHI in Per-Job microVMs: Isolation for Regulated Healthcare Data
The senders are hospitals with 1998-era interface engines, the formats are containers full of compressed pixel data and XML, and the parsers are C. Give every PHI job a machine you can afford to lose — and know exactly which parts of compliance that does and does not buy you.
Firecracker vs Xen: two generations of the same idea
Xen taught the industry what "cloud virtualization" meant. Firecracker came out of the same company with a deliberately narrower answer. This is not old vs new — it's two architectures tuned for different eras.
Nested virtualization and Firecracker: what actually works
"Can I do nested virtualization with Firecracker?" is two completely different questions wearing one trench coat. One has a yes-with-caveats answer. The other is a flat no, and that's usually fine.
What Runs as PID 1 Inside a MicroVM (and Why It Matters)
The kernel boots, mounts a rootfs, and executes exactly one program. That program's job description is short, strange, and easy to get wrong — which is why sandboxes hang, leak zombies, lose their last log line, or take thirty seconds to stop.
virtio-blk Discard and TRIM in Firecracker, Explained
A job downloads 6 GB, does its work, deletes it, and the host-side image is still 6 GB. Deleting a file is a metadata edit in the guest's own allocator; the host never hears about it unless somebody issues a discard. Every link in that chain fails silently.
Landlock explained: unprivileged filesystem sandboxing in the Linux kernel, and where it stops
Landlock is the rare Linux security module that needs no root and no sysadmin: a process hands the kernel a list of directories it promises never to leave, and the kernel holds it to that promise forever. Excellent inside a boundary. Not a boundary.
The Best Ephemeral CI Runner Platforms in 2026
A shared CI runner is a build cache, a credential store, and a mutable filesystem that every pull request gets to write to. Ephemeral means one job, one fresh machine, destroyed after — the interesting question is what that costs you.
Running Fuzzing Harnesses and Crash Reproduction in MicroVMs
A fuzzer is a professional vandal you hired on purpose. Its entire job is to push your parser into states the author never imagined — so don't run it on a kernel you share with anything you care about.
Isolating Per-Tenant CSV and Bulk Import Pipelines in MicroVMs
Your "Import your data" button accepts arbitrary bytes from anyone with a trial account. Zip bombs, 4GB single lines, formula injection, and a spreadsheet parser made of C. Give it a machine you can throw away.
Database Branching with Copy-on-Write MicroVMs
Branching a database means giving someone a private, writable, instantly-available copy of real data. There are two ways to build it: copy-on-write at the storage page level, or forking the entire machine — disk and memory — so the branch inherits the warm buffer pool and a postmaster that never noticed it was cloned.
Isolating Smart Contract Simulation and Forked-Chain Testing in MicroVMs
Simulating a contract means running two kinds of untrusted code: the bytecode, and the ordinary JavaScript that deploys it. One of those can read your archive-node API key out of the environment. Give each simulation its own machine, exactly one upstream, and a pinned block height.
Firecracker Hugepages for Guest Memory, Explained
Backing guest RAM with 2 MiB hugetlbfs pages means one page fault covers 2 MiB instead of 4 KiB — 512x fewer faults to populate the same memory on restore. The part nobody documents: hugepage-ness is a property of the snapshot, not a runtime flag, and Firecracker will only restore such a snapshot through the userfaultfd backend.
What's Actually Inside a Firecracker Snapshot
One file is kilobytes of structured VMM state. The other is a flat, sparse copy of every byte of guest RAM. Almost every clever thing anyone has ever done with microVM snapshots is a trick played on the second file.
Firecracker Metrics and Logger FIFOs, Explained
Firecracker has no /metrics endpoint on purpose — it pushes JSON to a file descriptor your supervisor owns. Which means your collector is now load-bearing infrastructure, and a named pipe nobody is reading can wedge a running microVM on a write(). Here's the design, the footgun, and the collector loop that survives it.
Firecracker vs AWS Nitro Enclaves: Two Different Threat Models
One protects your host from other people's code. The other protects data from your own operators — including you. People reach for the wrong one constantly, and only find out when they try to SSH into an enclave that has no network, no disk, and no shell.
PandaStack vs GitHub Codespaces
Both give you a computer in the cloud with your repo in it. One is optimised for a person with an editor; the other for a program spawning hundreds of VMs an hour. The tell is whether a `for` loop is creating them.
Best Sandbox APIs for TypeScript AI Agents in 2026
You're building an agent in TypeScript — Vercel AI SDK, LangChain.js, Mastra, or a hand-rolled tool loop — and something has to run the code the model wrote. This is about the SDK you'll actually live in: typed results, streaming, AbortSignal, ESM, bundle size, plus an honest pass over the field.
Per-Tenant AI Voice Transcription in MicroVMs
Your transcription service holds a customer's support calls, a clinic's dictation, and somebody's deposition in the same Python process, with ffmpeg parsing whatever container format arrived. A malformed .wav is an unsolicited code-execution proposal. One microVM per tenant makes it a boring one.
Running Per-Tenant Billing and Usage Metering in MicroVMs
Most isolation bugs leak data. This one mails a customer an invoice built partly from a competitor's usage. The only bug class where the incident review includes your CFO — so make cross-tenant reads structurally impossible, not merely unlikely.
Testing Browser Extensions with AI Agents in MicroVMs
An extension gets content-script access to every page you visit, your cookie jar, and a background worker that can phone home. Installing one to 'just test it' on your laptop is a trust decision. Do it in a microVM you throw away.
How to Sandbox an Untrusted composer install
`composer install` is a build step the way a stranger's USB stick is a file transfer. Scripts and plugins run arbitrary PHP before your app loads a single class — here's how to contain that.
Firecracker vs Amazon ECS Anywhere: Two Different Questions
ECS Anywhere answers "can AWS schedule things on my hardware?" Firecracker answers "can each workload get its own kernel?" They're not competitors — they're answers to different questions, and the crux is that external ECS instances run containers on your shared host kernel, not Fargate's microVMs.
Firecracker virtio-net RX/TX Queues Explained
A virtqueue is a ring buffer with commitment issues. Here's how a packet actually crosses the guest/host boundary in Firecracker, why there's one RX/TX pair per net device and no multi-queue, and the tuning levers that really exist — plus how to measure instead of guess.