Svelte is everything a developer could ever want for flexible, scalable frontend development. I feel like React has reached a maturity level where there needs to be new syntactic sugar added (I'm looking at you, hooks!). I love how Svelte sets out to rebuild a new language to write interfaces in from the ground up.

Generally I would advise you pick Node.js for your backend if you want to run a GraphQL service. The main reason for this is the tooling and support you get from the language around GraphQL and the native feel due to the spec being initially written in JavaScrip for JavaScript. However that isn't to say that you couldn't use Go for a service underneath your GrahpQL layer - but I would say that's probably complicating it too much to begin with.

Node.js has great support for reading from databases and using a server such as Koa will give you great performance (we operate several Node.js services in Koa with over 1000req/s). Additionally it keeps your initial simple stack in the same language so it will be easier for you to jump backwards and forwards.

If you were not to use GraphQL then I'd say it's really up to you whether you want Go in your ecosystem or not. It's a fantastic language and super performant, along with being more memory efficient than Node (if you are worried about costs at large scale).

If you're at infancy stages and haven't picked certain parts - and this is a customer facing application - then I would recommend you look at Preact instead of React and URQL (instead of Apollo Client). Both are great libraries that are very performant and don't need much advanced learning. Additional swap out MySQL for PostgresSQL (they are interop primarily, but offers you more features as you grow) for its ACID compliance, better performance at scale and support for NoSQL if you were to go that way.

It purely depends on your app needs. Does it need to be scalable, do you have lots of features, OR it is a simple project with very simple needs - many of those parameters clarify which technologies will fit.

If you are looking for a quick solution, that reduces lot of development time, take a look at postgraphile (https://www.graphile.org/postgraphile/). You have to just define the schema and you get the entire graph-ql apis built for you and you can just focus on your frontend.

On frontend, React is good, but also need to remember that it is popular because it introduced one way data writes and in-built virtual dom + diffing to determine which dom to modify. Though personally I liked it, am recently more inclined to Svelte because its lightweightedness and absence of virtual dom and its simplicity compared to the huge ecosystem that React has surrounded itself with.

In all situations, frameworks keep changing over time. What is best today is not considered even good few years from now. What is important is to have the logic in a separate, clean manner void of too many framework related dependencies - that way you can switch one framework with another very easily.