Open-Source DevOps · fission

fission

Fission is an open-source serverless framework that runs on Kubernetes, allowing developers to deploy functions in multiple languages with minimal infrastructure overhead. It abstracts away Docker and Kubernetes complexity, offering automatic scaling and ~100ms cold-start times through a warm container pool.

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Source: GitHub — github.com/fission/fission

8.9k

GitHub stars

789

Forks

Primary language

Apache-2.0

License (OSI-approved)

Key facts

Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.

Field	Value
Repository	fission/fission
Owner	fission
Primary language	Go
License	Apache-2.0 — OSI-approved
Stars	8.9k
Forks	789
Open issues	73
Latest release	v1.27.0 (2026-06-22)
Last updated	2026-07-07
Source	https://github.com/fission/fission

What fission is

Go-based FaaS platform for Kubernetes that isolates language runtimes in environments, maintains warm container pools for fast cold starts, and supports event-driven triggers (HTTP, message queues, schedules). Functions scale automatically based on demand without custom configuration.

Quickstart

Get the fission source

Clone the repository and explore it locally.

terminalbash

1git clone https://github.com/fission/fission.git2cd fission3# follow the project's README for install & configuration

Need it deployed, integrated, or customized instead? DEV.co ships production installs.

Best use cases

Event-driven microservices on Kubernetes

Ideal for organizations already running Kubernetes who need to mix serverless functions with traditional microservices in a unified operational model.

Multi-language function deployments

Suitable for teams requiring polyglot function support (Node.js, Python, Ruby, Go, PHP, Bash) without managing language-specific infrastructure separately.

Fast cold-start requirements

Well-suited for latency-sensitive applications where ~100ms cold starts are acceptable and where warm container pools provide cost efficiency over sustained-running services.

Implementation considerations

Kubernetes cluster required: Fission assumes an existing, operational Kubernetes environment with appropriate resource allocation for function pools and control plane.
Environment/runtime management: Supported languages ship as pre-built environment container images (ghcr.io/fission/*). Custom language support requires environment definition; verify language versions match production needs.
Function trigger configuration: HTTP endpoints, message queue bindings, and scheduled tasks must be explicitly wired; no auto-discovery from code annotations.
Scaling tuning: Warm pool sizing, concurrency limits, and autoscaling thresholds are configurable but require understanding Kubernetes resource requests/limits.
Monitoring and observability: No built-in metrics or logging; integration with Kubernetes-native tools (Prometheus, ELK, etc.) is required for production observability.

When to avoid it — and what to weigh

No Kubernetes infrastructure — Fission requires Kubernetes as a foundation. Organizations without a Kubernetes deployment or expertise should consider managed FaaS platforms (AWS Lambda, Google Cloud Functions).
Ultra-low latency requirements — If sub-50ms cold starts are critical, Fission's 100ms typical latency may not meet requirements. Consider always-warm deployments or alternative platforms.
Minimal operational overhead desired — Fission adds a management layer atop Kubernetes. Teams wanting zero cluster operations should evaluate fully managed serverless offerings instead.
Heavy vendor lock-in mitigation needed — While OSS, Fission is Kubernetes-bound. Portability across cloud providers is contingent on Kubernetes availability; pure multi-cloud FaaS portability is limited.

License & commercial use

Fission is licensed under Apache License 2.0 (Apache-2.0), a permissive OSI-approved license. This allows unrestricted use, modification, and distribution, including in commercial products, provided the license and copyright notices are retained.

Apache-2.0 permits commercial use without restriction. No commercial license or support agreement is mandated by the license itself. However, production deployments may require independent support; confirm support availability and terms with maintainers or third-party providers before commercial rollout.

DEV.co evaluation signals

Editorial assessment — not user reviews. Directional, with an explicit confidence level.

Signal	Assessment
Maintenance	Active
Documentation	Adequate
License clarity	Clear
Deployment complexity	Moderate
DEV.co fit	Good
Assessment confidence	High

Security considerations

Fission inherits Kubernetes security posture (RBAC, NetworkPolicies, Pod Security). OpenSSF Scorecard and CII Best Practices badge presence indicate security awareness. Consider: function code isolation relies on container boundaries; secrets management requires Kubernetes Secrets or external vault integration; no built-in function-level access control separate from Kubernetes. Audit Fission's control plane components and environment images for dependency vulnerabilities before production deployment.

Alternatives to consider

AWS Lambda / Google Cloud Functions / Azure Functions

Fully managed FaaS with minimal operational overhead, better cold-start SLAs, and native cloud integrations. Trade-off: vendor lock-in and higher per-invocation costs at scale.

OpenFaaS

Also Kubernetes-native, simpler operational model, lighter footprint. Trade-off: smaller ecosystem, fewer language environments out-of-box compared to Fission.

Knative

Kubernetes-native serverless built on industry standards (serving, eventing). Trade-off: steeper learning curve, heavier resource footprint, requires deeper Kubernetes expertise.

Software development agency

Build on fission with DEV.co software developers

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fission FAQ

Do I need an existing Kubernetes cluster to use Fission?

Yes, Fission requires a functional Kubernetes cluster. It is not a standalone FaaS platform and does not provision or manage Kubernetes for you.

What languages does Fission support?

Node.js, Python, Ruby, Go, PHP, Bash, and any Linux executable. Language support is pluggable via environment definitions; see official examples repo for community-contributed runtimes.

How does Fission achieve ~100ms cold starts?

It maintains a pool of warm, pre-initialized containers with a dynamic function loader. On first invocation, a warm container is reused and the function code is loaded into memory, avoiding container startup overhead.

Is Fission production-ready?

Yes. It is in active development (v1.27.0+), has known production users (Apple, Unilever, Babylon Health), and is backed by sponsors. Assess operational readiness against your Kubernetes expertise and observability requirements.

Software developers & web developers for hire

DEV.co helps companies turn open-source tools like fission into production software. Our software development services cover the full lifecycle — architecture, web development, integration, and maintenance — delivered by software developers and web developers who ship. Engage our software development agency to implement or customize it for your open-source devops stack.

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