Dark's goals are to remove accidental complexity from writing backends, via:
- Instant infrastructure: create and scale infrastructure without thinking about it
- Deployless: Changes are safely deployed to production instantly
- making APIs as easy to call as functions
- Trace-drive development: use live requests to speed/improve development
- Integrated tooling: by integrating the editor, programming language and infrastructure, reducing a huge amount of surface area that can cause mistakes or take significant coding time.
Currently, we get 10 user signups a day, and on average, 0 of them stick. We do have developers who love Dark, but not enough.
The specific problem is that developers trying Dark today must trade one set of accidental complexity for another. While they get the advantages of Dark and they typically resonate with them, they also lose the advantages they have in most alternatives:
- developers need access to a large library of functions/modules/packages to access 3rd party services, such as Stripe, Twilio, Slack, etc -- this sort of thing is trivial in almost all other languages
- developers need to be able to trivially set up a user account system for their users (such as what they can accomplish using Firebase, Rails, Django, etc)
These are believed to be the major missing features. However, these missing features -- in order to be implemented with a great UX -- need the language and platform to expand to support having them be a great experience.
"v1" of Dark refers to the current state of Dark in August 2020. While this isn't really a v1, it serves as a reference point to discuss the shortcomings and challenges that we discovered by people using, creating, and maintaining it. Most parts of this document start by listing the problems in v1, and this document attempts to discuss overarching problems that users experienced.
Dark v1 is very much a "product" - each feature was built and supported directly. Dark v2 attempts to be more of a platform, where more and more features are built in a way that they can be extended, or their own versions created.
For example, instead of having a dozen built-in refactoring commands, we'll expose the Dark language within the editor, allowing people to write transformations in the editor, in Dark itself.
Many of the things that are built into Dark could be put in the package manager, such as refactoring commands, templates, etc. That way developers could add refactoring tools that would allow them or other to , for example, create handlers to receive API-specific webhooks, build CRUD generators, build tooling to automatically create entire API modules from swagger files, or automatically upgrade from deprecated interfaces to newer ones.
In the platformizing spirit, we also want to write as much of Dark in Dark as possible. Since Dark is much easier to write than most other languages, writing as many features as possible in Dark will lead to faster iteration cycles and so better outcomes. It will also allow contributors to contribute more easily to core services and features.
A core tenet of Dark is that everything is live. That means we need robust ways to carefully make changes to running applications. We have some already:
- all stdlib functions are versioned
- basic feature flag support exists
- static assets are all versioned
However, we want to support a situation where any change can be made carefully and incrementally, such as:
- versioning functions
- support carefully changing other features, such as types, secrets, and handlers
- db migrations
The rule here should be that all changes that affect the observable system to grandusers should be controllable and slow launched by the developer.
Right now, there are no access types and Dark can only be accessed by signed-in users. We want to support:
- users trying dark without logging in
- using the editor (including live values) embedded in other docs
- public canvases that can be edited by anybody (safely, that is, so solving things like access to traces, passwords, etc)
- granular ACLs for organizations
Dark v1 was built quickly and hackily, and was brittle in a number of senses. We cut every corner we could in an effort to get Dark far enough along to get feedback about how it works. Though we went back and reworked several components (in some cases several times) and iterated quite broadly, many problems surfaced because components of Dark were MVP quality.
This is true of product and language features (eg the error rail and feature flags), as well as simple usability (eg traces can be created, but not edited, searched, graphed, named, saved, etc). In a sense, we often only implement the "C" and "R" of CRUD.
I want to fully think through the problem spaces and their solutions, to deliver an excellent experience.
A number of examples:
- use a real type system to avoid all the hacks in v1
- use an async language/framework so that things like calling HTTP functions do not use all the resources, and so that functions like
sleepcan be supported
- abandon OCaml for a place with more mature libraries & community (probably rust or F#)
- GraphQL: one reason that Dark isn't as robust as it could be is due to the overhead of supporting each CRUD operation in the client is that we need to create APIs for everything. I want to look at using GraphQL to ease that.
Dark feels unsafe to users. They feel reluctant to make changes because they don't know if they will work, or if they'll break things. We need ways to make this safer:
- unit tests on functions and handlers will make users feel safe
- type checking:
- by having type checking on functions and handlers, users can feel confident that their code will work
- error tracking
- highlight (and email users about) errors in their apps
- highlight data being sent that isn't being used by the app (eg form fields)
- is this the same as warn/error log messages?
- application understanding
- email users about their traffic so that they understand that their code works
- allow people search their traces for
- feature flags:
- make feature flags global and easier to use and understand
- fix size of traces
- fix editor layout
- the layout of the canvas
- education so that users can understand