How to competently implement a portfolio for a backend developer in order to interest the customer?

Question

Freelance

I’ll note right away: please pay attention to interest the customer - this is the focus of the issue. That is, we are not talking about what kind of work you can create for a portfolio / training.

Back-end development is a kind of "invisible front", so it is very difficult to implement work for a portfolio on freelance. The problem is that buyers often look at work from a design perspective, which is not the job of a back-end developer.
Accordingly, the issue becomes very acute when there are projects for 2-3 months, and the customer, with a desire to save money, decides not to take the design, but prefers to take something from the same Bootswatch , or some low-quality free template.
The themes themselves are good, but without the "wow effect", besides, they are too "hackneyed". And if there are several such works in the portfolio, it can reach the point that clients can say "some works of the same type", although theirs may differ by 70-80%. As a result, a decent time may come, and the portfolio of work is getting older and older.
Of the options, I see switching to a market that doesn’t care much about the visual effect, namely: parsers and interaction with API / Webhook (connection of payment systems, bots, functionality associated with the API of a service).
UPD: The emphasis in the question is the lack of attachment to any freelance exchange.

Answer 1

The external supply of the product is not everything, although of course it is essential.
You can show the performance of your solutions, the ability of your backend to perform complex tasks in real time, "instant" response to user requests, task parallelization, fault tolerance - the ability of the service to work even despite bugs or failures in individual modules.
these are very important parameters that the customer can evaluate, of course, trying to climb into the market of developing landing pages, blogs on WordPress or online stores on Joomla as a backend developer - there should be a taboo for you there, the value of an intelligent backend developer tends to zero. You should not position yourself in a market where you are not needed and cannot have any advantages.
In the portfolio, also indicate about your "domain knowledge" in the subject area, this is also very much appreciated.

Answer 2

Are you sure that you need clients who expect a "wow effect" from the backend?
Anyone who is looking for a backend developer should already understand what he is, otherwise he will be required to design and layout and fix the printer

Answer 3

In my opinion, the best way to design a portfolio is in the form of cases (Case Study).
The following information is usually indicated:
- Name (not necessarily the technical name of the product, it can be in the style of "How I helped a large retailer save 100 million rubles a year");
- Client (company name, location, brief description);
- The problem with which the client came to you;
- The solution to this problem (can be accompanied by flowcharts and prototypes / screenshots of the UI);
- Your role + List of used technologies;
- The result that turned out as a result (if possible, give numbers before / after);
- If possible, provide feedback from the client;
You need to write in such a way that a non-technical person understands what it is about and how your solutions can help solve their problems. Issue - either on the site or make up in pdf.

Answer 4

Therefore, freelancing is very difficult to implement work for the portfolio.

A backender's portfolio is just a description of the projects they have been involved in.
Of course, there can be no references to "funny pictures" like a front-ender / designer here.
It's enough.
During the initial contact, a backender is often asked for an example of his code.
If the customer forgives you for an example of a site but not your code , then ... here my grandmother really said in two.