HardenBackend

$2,590Delivered in 4 weeks once your details are in30-day cover

What this package is

Harden is for systems where a mistake costs money. It covers taking payment so that if the bank reports the same one twice, nobody is charged twice, which a great many systems get wrong because every provider repeats a notification when a connection stumbles.

It moves heavy work into the background so nobody sits waiting, holds off bursts and floods so the system stays up, and logging with alerts when something goes wrong.

It finishes with a security review of the system I am about to hand you, run with the same tooling I use for clients in the security service, delivered with the findings and what was already fixed.

See it working

Three things that cost money when they go wrongPress all three and watch what the system does. No technical vocabulary needed.

Simulated eventsYour system

0Reports received

0 ordersRecorded as

The first one causes the most damage when it is missing. Every payment provider repeats a notification when a connection stumbles. A system not built for it records two orders and charges twice.

What the system did

Nothing pressed yet. Try the buttons above.

This mirrors the screen of the delivered system. Everything here lives in this page and is connected to no bank and no system. All three are things I have built against real money, and a security review is attached to the work at handover.

Everything you get

This list is the entire scope of the package. Nothing is hidden in a contract.

Everything in Admin
Takes payment, and if the bank reports the same one twice it is not charged twice. One payment provider connected.
Heavy work runs in the background, so nobody sits watching a screen
Bursts and floods are held off, so the system stays up for everyone else
The monthly summary sent to you by email, so nobody has to remember to open it
An immediate alert when a figure looks wrong, up to three conditions you choose
Logging and alerting when something goes wrong
A security review of the system I am handing you
60 days of support after handover

Not included in this package

Front-end design and build. This service covers only what sits behind it. If you need both sides, look at the business website or the booking system, which ship with a front end.
Monthly server and third-party costs, paid from your own accounts so the system genuinely belongs to you. I estimate the figures before we start.
Migrating data out of an old system with a complicated structure. Ordinary spreadsheets I move for free; pulling through a legacy API is quoted separately and told to you first.
Mobile apps. That is the Android service, which can call the API built here.
A registered company on my side. I am one developer working under my own name in Thailand, and the contract is with me personally.

What I need from you before starting

Every question needs an answer, because these are the settings your system is built from. None of them can be skipped. If one is not settled yet, put down what you know today and we adjust it when work starts.

Everything Admin needs Required

The data shape, the roles and the admin still have to be known.

How do you take payment Required

Each provider reports back differently and retries under different conditions. Doing this correctly means knowing the real one.

What is slow enough that people sit waiting Required

Those are the jobs that belong in the background. Without knowing which, I cannot know what to move.

How many people use it at once, and when does it peak Required

It sets the rate limits. Too low and real customers are blocked; too high and nothing is protected.

Who should be told when something breaks, and how Required

An alert nobody sees is not an alert. It has to arrive where somebody actually looks.

Is there a security standard you have to meet Required

If something has to be passed, building to it from the start is far cheaper than retrofitting.

How the work runs

Send me what already exists

The front end you have built, the spreadsheet you run on, or the old system still in production. Any one of those is enough to start scoping.

We agree the data shape before code is written

You get the data structure and the list of what the system will do, to review first. Changing it as a document takes ten minutes. Changing it halfway through the build takes three days.

Your team uses the real thing while it is still being built

The system and its documentation open up in stages, so front-end work runs alongside rather than discovering a mismatch at the end.

Handover somebody else can pick up

Source code, API documentation, tests, deploy instructions and an admin manual, plus support after delivery.

Paying and getting started

Full price of this package$2,590

Paid in full at order The price is fixed and the scope is written out. No numbers appear later.
Work starts as soon as it lands No call to book and no quote to wait for.
30 days of cover after delivery Anything wrong with my work is fixed at no charge.

Bank transfer or PromptPay. A receipt is issued every time, and a stamped work contract if you want one.

How to reach you

Your namePhone, LINE or email

Questions about this package

How do you stop a repeated call charging twice?

Every money-related request carries an identifier. The system remembers which identifiers are done and returns the original result rather than repeating the work. It sounds simple; where people get it wrong is deciding at which layer to remember and for how long, which I have already worked through on systems handling real money.

How is the included security review different from your security service?

This one reviews the system I have just built, before handover, and covers what I wrote. The separate service reviews systems built by others or already in production, which is broader and includes testing from outside.

Do background jobs need another server?

Usually not. At this size a queue service with a free tier is enough. If volume grows past that I give you the figure in advance, and it is a third-party cost paid from your own account rather than mine.

If it goes down at three in the morning, who is watching?

This package makes the system able to raise an alert. It does not include somebody watching around the clock. For ongoing cover after handover, that is the monthly care service. I keep them separate so you are not paying for monitoring inside a one-off price.

Why buy this if it already works from the first package?

If your system does not touch money and traffic is modest, the first or second package really is enough and I will say so. This one exists for when a single mistake has a price: charging twice, going down as a sale opens, or leaking customer data. All three cost far more to fix afterwards than to prevent.

Often booked together

android-app platform monthly-care

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