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Hire a Firebase DeveloperHire a Firebase developer for security rules, functions and bills

App369 is one Firebase developer, Simon Dziak, who audits and fixes existing Firebase apps. A Security Rules Audit with a fix pull request is $950 in 5 business days. A Cost-Cut Audit of your bill is $750, 5 business days after read-only access. One bug you can name starts with a $450 diagnosis in 3 business days.

Fixed prices

All fixed-price offers

Something else? Describe your project

Check it yourself

How do you check a Firebase app before hiring anyone?

Firebase’s docs list rules that give every user, or every signed-in user, access to all your data as not recommended. These 3 checks need only your code.

CheckRun thisA pass looks like
Do your rules let anyone read or write everything?grep -rnE "if true|request\.auth != null|request\.auth\.uid != null|allow read, write;|\.(read|write).: *(true|.auth)" --include="*.rules" --include="database.rules.json" . --exclude-dir=node_modules --exclude-dir=.gitLook at every match. A rule that only checks for a signed-in user lets any signed-in user read or change every customer’s data; each rule should compare the user’s ID with the owner of the document. No match isn’t proof your rules are safe: rules that call a helper such as isSignedIn() need reading by hand, and public reads with owner-only writes are fine.
Is a service account private key in the repo?grep -rlE "\"private_key\"|BEGIN PRIVATE KEY" . --exclude-dir=node_modules --exclude-dir=.gitNo matches. Google says to store service account keys separate from source code. If one was ever committed, delete the key in IAM, because removing it from the repo isn’t enough. Code running on Google Cloud can use an attached service account instead of a key.
Where is the Firebase web API key, and is it restricted?grep -rn "apiKey" . --include="*.js" --include="*.ts" --include="*.dart" --exclude-dir=node_modules --exclude-dir=.gitA match is normal: Firebase says its API keys are safe to include in code. Grep can’t show restrictions, so open the key in the Google Cloud console: Firebase calls API restrictions critical, because an unrestricted key can be used to access any API enabled for the project.

What gets fixed

What does a Firebase developer fix?

Market rates

What does it cost to hire a Firebase developer?

Hire marketplaces fill page 1 for this search, and most quote by the hour. These figures come from their own pages, read November 8, 2026.

  • Lemon.io: senior engineers from $55 an hour

    Lemon.io’s Firebase page lists senior engineers from $55 an hour, and its budget calculator shows a typical range of $41 to $60 for a senior developer with 6 years’ experience. Work starts with a paid trial of 20 prepaid hours.

  • Toptal: no published rate

    Toptal’s Firebase page publishes no hourly rate and starts each engagement with a trial period of up to two weeks.

  • App369: $950 for a rules audit and fix

    One fixed price for a scoped result, paid before it starts: the emulator test suite, a severity report and a pull request that passes it, in 5 business days. At Lemon.io’s from-rate for senior engineers, $950 buys about 17 hours.

    See the Rules Audit offer
  • Firestore
  • Cloud Functions
  • Firebase Authentication
  • Cloud Storage
  • Security Rules
  • Firebase Emulator Suite
  • Cloud Run
  • Flutter
  • Node.js

Error fixes

Firebase errors Simon fixes

Each page covers one Firebase error, with Google’s docs as the source and what to check first.

FAQ

Questions before you start

How much does it cost to hire a Firebase developer?

App369 publishes fixed prices: a Firebase Security Rules Audit with a fix pull request is $950, a Firebase Cost-Cut Audit is $750, and one named bug is an App Fix Ticket, a $450 diagnosis credited toward the $1,200 fix. Lemon.io lists senior Firebase engineers from $55 an hour.

Which offer fits my problem?

If you worry one customer can see another’s data, start with the Rules Audit. If the Google bill keeps growing, start with the Cost-Cut Audit. If one thing is broken and you can describe it, start with an App Fix Ticket.

Will you touch my production data?

No. Rules are tested on the Firebase emulator or test data, the cost audit uses read-only access, and fixes arrive as pull requests you deploy yourself.

What isn’t included?

New features, rewrites or migrating off Firebase, app refactors, infrastructure outside Firebase, making the changes the Cost-Cut Audit recommends (a fixed-quote add-on after the audit), negotiated discounts or Google Cloud credits, guaranteed app store approval, compliance certification, changes to your production data, and calls, except paid consultations ($100 per 15 minutes, paid upfront).

Who does the work?

Simon Dziak, who founded App369, does the work himself, in writing by email. He built and runs Workspace369 on Firebase, Cloud Functions and Cloud Run.

Sources

Not a fixed-price job?

Describe it and get a written quote

Send what you need built or fixed. You get a written scope, a fixed price and a timeline; Simon replies by email, usually within one business day.

Describe your project Instant quote

Prefer a call? Consultations are $100 per 15 minutes, paid upfront.