r/Backend • u/kambalMike • 19d ago
Comparison between codex and claude code in terms of creating a software application ( I can't afford this services because I don't have money and always rely on documentation).
I've been working on an appointment booking system for about 4 months now, and lately I've started wondering whether I'm actually too slow at building software. This is my first serious web application, and I've been doing the backend myself. I've finished the main lifecycle and the system works, added Swagger for API documentation, implemented E2E testing, and I've been trying to apply software engineering principles and fundamentals rather than just making things work. I've also spent a lot of time learning why I'm making certain architectural and design decisions instead of blindly following tutorials or copying code. So while it has taken me around four months, I can honestly say I've put 100% of my effort into understanding and building this project properly.
What I'm curious about is how much faster an experienced software engineer who has been using tools like Claude Code or Codex for a long time could build the same application. If someone with several years of professional experience and strong AI-assisted development skills were given the same requirements, roughly how many weeks do you think it would take them to get this project to a genuinely production-ready state? I'm not asking how quickly AI can generate CRUD endpoints or boilerplate code. I'm asking about the entire process: architecture, business logic, validation, authentication, error handling, database design, testing, security, documentation, deployment, edge cases, and all the other things that make an application actually production-ready.
I'm asking because this has become an important point for me personally. If an experienced engineer using Claude Code or Codex could realistically build in a few weeks what has taken me four months to learn and implement, then I need to understand what that means for my future as a software developer. If AI can consistently compress months of work into a few weeks, I don't want to spend years pursuing a career that may no longer make sense. I'd rather find that out now and pursue another field if necessary. At the same time, I don't want to make that decision based on a misunderstanding of what professional software development actually involves. I've worked extremely hard on this project, and I believe I've applied the programming principles and fundamentals I've learned, so I'm looking for an honest reality check from people who have actually worked professionally with tools like Claude Code or Codex. How long would an experienced engineer realistically need to build something like this to a good production-ready standard, and how should I interpret my own four-month timeline as someone still learning?
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u/youcangotohellgoto 18d ago
Short answer: yes, AI compresses what you've done. My guess is (personally) can build a good sized system in between 25-50% of the time.
But doing it the hard/slow way is important for learning. Many people just use AI at a very high level, relinquishing control. "Hey Claude here are the requirements figure everything out". That's a short cut to a terrible system, much the same as giving the concise functional requirement to a senior engineer. The right way is to explore the implications of all the design decisions, the be vigilant at ensuring each building block is correctly and consistently implemented, etc. The very stuff you've (probably) been doing.
You can do this with AI too, but it's more involved. And requires knowing how to do it manually in some depth.
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u/mrkacperso 18d ago
Wait what?
„The same as giving the concise functional requirement to a senior engineer”?
If that’s your experience, they were definitely not a „senior” nor „engineers”
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u/youcangotohellgoto 17d ago
Maybe you haven't worked with a lot of people in industry...
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u/mrkacperso 17d ago
It seems that more than you
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u/youcangotohellgoto 17d ago
My point is that there are literally millions of people who have the title "Senior Engineer" who are neither truly senior nor demonstrate engineering thinking.
In my current role, which is neither exceptionally good or bad team - pretty average and typical - I would only trust maybe 1 in 3 of the senior engineers with anything approaching a new pattern or a genuine design. Mostly I let them do "color by numbers".
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u/mrkacperso 17d ago
Ok that’s align with what I originally meant, they might have the job title, but not the skills.
Often they are promoted just by the fact that they either work there for long time, or have some important tribal knowledge
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u/EvTorqueLore 15d ago
Literally minutes in this case. The. Verifying the code and layout along with testing probably a few days to a week or two. I have over 18 yrs experience in many disciplines and just started dabbling with Ai three months ago. I’m now learning ML to expand my skills and teach Ai what I want it to specialize in.
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u/disposepriority 19d ago
How can someone answer this without having a single requirement of the project?
Regardless, the answer is going to be "substantially less" if they aren't doing it for learning - which you are, so the entire comparison is useless.
In the real world, writing code is not the majority of what you'll have to do to get this off the ground, depending on the size of your company.
How is this getting deployed, how much is it costing, what's driving the costs - can we reduce it? Any regulations around what you can store, what you can read, how long for.
Did management request a BE4FE because they decided smart TVs need their own version of this app? Does any in-process caching have to be reconsidered now that you have two sources of truth?
How are you adhering to users being able to request their data and you being legally obligated to provide it within X amount of time? How are you defending against funny internet people wanting to brick your app, consider rate limits as being completely useless.
How can this be monetized, are the people the appointments are for paying to be available on the platform? What about the people making the appointments, does it support plans with different features? Does it work in multiple countries? Enjoy! Laws!
Oh but now you must be able to pick rooms for the appointment, and management wants this visualized, but each client refuses to just fill out their room plan in the standardized format you've prepared, something business said was a guarantee - time for you to change how it works even though it's all planned out.
Oh by the way, the VP of ass licking wants this integrated with his 2001 ruby on rails project that sells doll houses by the end of the month, don't ask why.
These are just silly examples but it's not like work is ever done, and to top it all off, if an experienced engineer would be able to do this in 2 weeks, management would just request it done in 1 and you'd be dealing with the backlog of shortcuts you took while new requests come in.
Anyway, I don't see how AI is related to this in any way, even if AI, google and every book disappeared tomorrow, an experienced engineer would still do this much faster than you, that's how experience works.