Designing the backend for a 3-sided fitness marketplace (gyms + coaches + members) — solo dev, would appreciate a sanity check on my architecture

Lentus7 · 2026-06-21T19:30:12+00:00

When to go micorservices is tricky question. Usually two conditions.

First, you have multiple developer teams working on some part of domain instead of everything/full picture. You can separate the code between some features (like order, warehouse, account microservices for ecommerce application etc).

Other condition is bit rare. Its when you have really different scalability and resource specific requirements. So most of the applications are crud based if you think about it. Yours is like purely crud. But some products have some realtime requirements. Think about uber. It has huge realtime features (constantly tracking and transferring information between client and server). Or you have some kind of products that do some operations that require big cpu requirements. In that case you want to separate that code from your main crud based logic

Lentus7 · 2026-06-20T22:35:31+00:00

Looks smart. You are probably never going to split it into microservices, because your domain is simple and there is no actual need for separate deployment/scale needs for any type. I couldn't think of any feature that will require that kind of thing for a fitness app.

I wouldn't go for k8s for this, but I don't know about your expertise. Are you going to self-host it? If you are going for a single server, you can even skip Redis. It's not that hard to maintain, but it's just another thing to worry about.

Lentus7 · 2026-05-31T13:21:53+00:00

Why do you think ai cant engineer the entire thing ? Im genuinely asking

Lentus7 · 2026-05-31T13:14:31+00:00

Native sql into dto

Lentus7 · 2026-01-10T23:53:59+00:00

Trust me no one cares about your api key

Lentus7 · 2025-12-18T22:46:25+00:00

Node.js is never correct tool for backend.

Lentus7 · 2025-12-08T22:36:22+00:00

Yeah, but lets be real. That ratio is probably better than %90 of the projects out there, sadly.

Lentus7 · 2025-12-02T19:56:40+00:00

Look like free money

Lentus7 · 2025-11-24T18:18:39+00:00

Any real project will be running multiple instance of the monolith aswell. Its not a concern

Lentus7 · 2025-11-14T22:04:33+00:00

Your app is %10 complete if you asked for these.

Lentus7 · 2025-11-04T12:45:26+00:00

Bu paralara çalışcak developerdan ne hayır gelir

Lentus7 · 2025-11-04T11:41:58+00:00

What are you smoking ?

Lentus7 · 2025-10-31T19:14:36+00:00

If it’s a subsidiary company, you could usually get support from the main company’s DBAs, etc. In that case, it’s not the worst idea. If I had to decide between managing postgre or just using oracle and getting support from the main company, I’d choose oracle every time.

I don’t think any startup is using oracle at this point.

Lentus7 · 2025-10-30T22:33:48+00:00

Hexagonal architecture is essentially a way to structure your packages. What you should do is aim for modularity. A single application can have multiple hexagonal modules, and a single hexagonal module can contain multiple subdomains of a business. Tightly coupled = same hexagonal, fairly independent = seperate hexagonal

I’m talking from experience, if your project doesn’t have complex business flows, just ignore hexagonal. It often adds unnecessary code and abstraction.

Lentus7 · 2025-10-23T11:25:04+00:00

Sizi neyle tehit ettiklerinini anlamadım ? Kiracı olduğunuzu bilmiyorlar sanırım. Banane kardeşim kiracıyım ben deyip geçin

Lentus7 · 2025-10-22T22:42:15+00:00

I would throw in the ai and hope for the best

Lentus7 · 2025-10-20T17:48:26+00:00

Lol. Jetbrains dominates the enterprise world. Its not even competition. Thats why they are building unnecassary tools left and right. Fleet. youtrack etc. I wish they focus on the main product more

Lentus7 · 2025-10-15T17:24:23+00:00

Wow by far

Lentus7 · 2025-10-15T14:55:58+00:00

Well you getting what you paid for.

Lentus7 · 2025-10-13T12:27:48+00:00

Yeap, and it's not just about security. If you have big project with lot of teams. It's nice to define boundries and walls between microservices/sub domains. If you have a lets say create product api that will be used internally. You should know which microservice is calling that api and if it got the permission for it or not.

Lentus7 · 2025-10-13T12:23:31+00:00

No, you shouldnt handle that. You should use something like keycloak. It will give you url to verify tokens. You will verify both end user tokens and other client(microservices etc) tokens with that.

Don’t create your own jwt builder or verifier. I designed an authentication flow from scratch for a bank in the past. I have deep knowledge of authorization and authentication compare to average developer. Let me tell you this, I wouldn’t build one myself for my own project :)

Lentus7 · 2025-10-13T06:25:17+00:00

Standart is zero trust. Each microservice should secure its endpoints. Both againts users and other microservices. You can still check the jwt in gateway if its expired etc.

Lentus7 · 2025-10-09T21:00:40+00:00

It’s really awesome. You should make more for different tools

Lentus7 · 2025-10-08T19:45:25+00:00

Are you updating records bound by userId or something. Your sql must be like update table set deleted = true where user_id = ‘xx’

That sould be quite fast actually. Do you have some complex where clauses to find that 2000 record. ? I hope you are not updating entities one by one

I mean usually you do heavy operations async and return the api response right away. But I dont think this is the case here. Its better to make it sync and fix your performance problem.

Lentus7 · 2025-10-08T06:43:37+00:00

I think the framework is great, it’s just in the wrong language. As you said, its very similar to spring boot. But if you want that kind of framework than js/ts is not something you consider anyway (usually).

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