Backend, API & Integrations

Backend, API & Integrations

The part you never see, and the part that wakes you at 3am.

The API, database and infrastructure your app runs on: built to stay fast as you grow, built to connect to the systems you already run, and built with the bill capped before launch day.

Your cloud accounts, in your name, from week one. Your code, your data, your keys.

52+
Apps and products delivered
7+
Years
Top Rated
Upwork agency
100%
Job Success
54
Client reviews

Products running on backends we built

What usually goes wrong

What clients say, and what it actually means

What we hearWhat it really means
Does it allow you to set a billing limit, or is it one of those exciting cloud services where no matter what you do you are always one mistake away from losing your house?Nobody capped the bill. The bill that arrives when you are not looking
I am outsourcing my first app and want to know who hosts all the database and images. I am guessing it is me?Nobody told them who owns the infrastructure. Your accounts, your keys, your data
Vendor lock-in. When Google or Firebase says jump you have to say how high.The convenient choice became the permanent one. Firebase, Supabase, or your own
Migrating data and moving to your own solution might be a problem later.The day-one decision was never revisited. Firebase, Supabase, or your own

Who you’ll actually work with

Anand Yadav, Founder of SightInfusion Infotech

Anand Yadav

Founder, SightInfusion InfotechUpwork Top Rated100% Job Success54 client reviews52+ apps and products delivered

The backend is where I get called in after somebody else built it. Almost always for one of two reasons: the bill went somewhere nobody expected, or the thing that worked with a thousand users stopped working with fifty thousand.

Both are decisions, not accidents. Both are made in the first two weeks, usually by somebody moving fast, and both are cheap to get right at the start and expensive to fix later.

So on this service I will tell you the boring version. Where your data lives, whose name is on the account, what it costs at ten times your current size, and what it would take to move away from us. If a developer will not answer those four questions, that is your answer.

Cost control

The bill that arrives when you are not looking

Cost control is part of the build, not an afterthought.

This is the number one fear in this market, and it is not irrational. Documented, public cases:

What happenedThe billSource
A runaway recursion on Google Cloud Run and Firestore. The bill went from $5,000 to $72,000 in two hours. The team did not find out until the next day.$72,000 (later waived by Google)The Register
A forgotten public API key was found and hit with 60,000+ requests, straight through a $1,400 spending cap.$18,000+ on a $7 budgetTom's Hardware
A running catalogue of the same failure: infinite loops, unbounded queues, bandwidth blowouts.$8.8K, $36K, $46K, $100KServerlessHorrors

The uncomfortable detail: in the named cases above, the client had some form of budget in place. Spending caps on cloud platforms are usually alerts, not brakes. They tell you afterwards.

So this is what we do before launch, on every backend we build:

  • Hard instance and concurrency limits on every service that can scale: the actual brake, not the alert.
  • Rate limiting per key and per user, so one leaked key cannot become a bill.
  • Key rotation and secret scanning in the pipeline, so a key never reaches a public repository.
  • Per-service budget alerts at 50%, 80% and 100%, to you, not only to us.
  • A costed load test: we tell you what 10x your traffic costs before you have 10x your traffic.
  • We show you where the switches are and put them in the runbook, so it is not knowledge that leaves when we do.

It takes about half a day. It is the cheapest insurance in the project.

When you should not hire us

Firebase, Supabase, or your own backend? An honest answer.

Use Firebase or Supabase when

  • You are building a first version and speed matters more than anything. Real-time sync, auth and storage arrive on day one instead of week three.
  • Your data shape is simple and your queries are predictable.
  • You would rather pay per use than pay for a build.
  • You accept that the ceiling exists, and you would rather find it with real users than guess at it now.

Build your own when

  • Your queries have outgrown it. Filtering data on multiple nested conditions gets slow and awkward without fetching half the database.
  • The bill has stopped tracking your revenue. As your application scales you will not like the invoices you get every month.
  • You cannot afford the platform's decisions to be yours. When Google or Firebase says jump, you have to say how high.
  • You need to be somewhere specific: data residency, an on-premise system, or a client who requires it.

That is a genuinely good trade, and on most MVPs a managed platform is the one we recommend.

The migration is real, and we will not pretend otherwise. Developers who move off Firebase describe going through months of work migrating everything to their own backend because of constant hassle at scale. Moving later is a project, not an afternoon. That is not a reason to avoid Firebase. It is a reason to decide on purpose rather than by default, and to design the data layer so that moving is possible.

How we design for the exit from day one: all data access goes through one layer of our own, not scattered through the app. It costs a few extra days at the start, and it is the difference between a migration that takes weeks and one that takes months.

Integrations

Connecting to everything else you already run

An app that does not talk to your other systems creates work instead of saving it. Somebody always ends up copying data between screens.

What we connectIncludes
PaymentsStripe, Razorpay, PayPal, in-app purchases. Subscription and billing logic lives on SaaS Development.
Business systemsCRM, ERP, accounting, inventory, HR, including the old one nobody wants to touch.
IdentitySocial sign-in, biometrics, SSO, KYC providers.
MessagingPush, email, SMS, WhatsApp.
Logistics and fieldShipping, tracking, mapping, device and IoT feeds.
AI servicesModel APIs, vector search, and the usage caps that keep them from becoming a runaway bill.

What we deliver with every integration, and what most quotes leave out:

  • What happens when it is down. Every external system fails eventually. The integration map says what your app does when it does: queue, retry, degrade, or tell the user honestly.
  • What happens when it changes. Version pinning and a monitored alert, so a provider's API change is a ticket and not an outage.
  • What it costs per call, where the provider charges per call.
Proof

Tata Power SolaRoof, an enterprise field application integrated with the systems the client already ran. Lead-to-order 45% faster, asset tracking 99% accurate, KYC from days to minutes.

See the case study

Standards

How we work to spec

  • Every merge reviewed by a person. AI writes code here, it does not approve it.
  • The API is documented as it is built, not written up at the end.
  • Backups are configured and restored once, as a test, before handover. An untested backup is a rumour.
  • Load tested at 10x current volume, with the results written down.
  • Secrets in a manager, never in the repository, with scanning in the pipeline.
  • Staging environment that matches production, that you can access.
  • Your accounts, your keys, your data, from week one.

Standards

Standards for the API itself

  • REST or GraphQL, chosen for your case, and we will tell you why, in plain words.
  • Versioned from v1, so tomorrow's change does not break yesterday's app.
  • Consistent error responses, so the app can behave sensibly instead of guessing.
  • Pagination and rate limits designed in, not added after the first slow screen.
  • Authentication and roles decided before the first endpoint, never retrofitted.
  • A test suite that runs on every push.

Industries

Industries we serve

IndustryWhat we have builtProof
Fintech and bankingWallets, lending, KYC, crypto, real-time settlementFidex Wallet · QuickChain · Hindustan Loan
Legal-techCase data, document systems, auctionsGavel Auctions · DigitsLaw
Energy and utilitiesEnterprise integration, field data, asset trackingTata Power SolaRoof
Retail and POSInventory, multi-platform syncVencru POS
CRM and internal toolsData-heavy systems that grew 100xPM Fund Manager · FMSoft CRM
Events and communityReal-time chat and messaging at scaleVirtue Insight
Healthcare and wellnessOpen, no case study yetNo claim made

What sits behind the app

The part nobody sees is the part that wakes you up

Screens fail politely. Backends fail at three in the morning, for everyone at once. The standards below exist because of that difference.

A broadcast mast transmitting from a phone

Process

How we work

1

First call

What the app has to do, and honestly whether a managed platform like Firebase would do it.

30 min
2

Data and integration map

Every entity, every external system, every failure case, on one page.

3 to 5 days
3

Architecture decision, written down

Including what it costs at 10x and what leaving us would involve.

2 to 3 days
4

Accounts opened in your name

Before any code. Cloud, monitoring, error reporting.

1 day
5

Build the API in two-week blocks

Documented as it goes, with a staging environment you can reach.

2 weeks each
6

Integrations, one at a time

Each with its down-behaviour defined.

2 to 5 days each
7

Load test and cost test

10x volume. You get the numbers and the monthly cost at that volume.

2 to 3 days
8

Caps, alerts, backup restore test

The spending brakes and the restore drill, both checked before handover.

1 day
9

Handover and runbook

Deploy, roll back, who to call, what the alerts mean.

2 to 3 days

Engagement

How we work together

ModelBest forHow it works
Backend reviewYou have a backend and you are worried about cost, speed or scalePaid, fixed price, fixed length, credited back in full against work that follows.
Fixed-scope buildThe data and integration map is agreedOne price, one date.
Two-week blocksThe product is still movingPriced per block, stop whenever you like.
Monthly retainerOngoing scale, monitoring and integrationsSee Mobile App Maintenance & Optimization.

No minimum contract size.

What changes the price

Pushes it up

  • Real-time features: chat, live tracking, settlement
  • Many integrations, especially with old systems
  • Regulated data
  • High volume or heavy reporting
  • Data residency requirements
  • Migrating off an existing backend

Pulls it down

  • A managed platform is genuinely enough
  • Few integrations
  • We also built your app
  • Your data model is already stable
  • You have no legacy system to talk to

You get a fixed number after the data and integration map: three to five days. Before that, anyone quoting you is quoting a guess, and on backends the guess is usually wrong by a multiple, not a percentage.

What clients say

I recently collaborated with Anand and his team on creating my finance mobile application and I was thoroughly impressed. Their technical expertise ensured seamless updates, and their proactive communication kept me informed throughout the process.

Client name neededFlutter mobile application developer for a fintech projectRead on Upwork

Anand is a highly knowledgeable Flutter developer that provided valuable and fast help on our project.

Very responsive and hard working person. He is dedicated to his work and can certainly do all the allocated task.

Stack

Tech we use

Backend
Node.jsTypeScriptFirebaseSupabase
Databases
PostgreSQLFirestoreRedis
Cloud
Google CloudAWS
APIs
RESTGraphQLWebhooks
Payments
StripeRazorpayPayPal
Messaging
PushEmailSMSWhatsApp

APIs versioned and documented. CI/CD, staging that matches production, error monitoring, uptime and budget alerts, on every project.

FAQ

Questions buyers actually ask

Who hosts my database, is it me?

Yes, and that is deliberate. Cloud accounts are opened in your company name in week one and billed to you. We work inside your accounts. See how we work to spec.

Can I just use Firebase?

Often, yes, and on a first version we will usually tell you to. The honest version of when it stops being the right answer is in Firebase, Supabase, or your own.

What stops me getting a $70,000 bill?

Hard instance and concurrency limits, per-key rate limiting, secret scanning, budget alerts at three thresholds, and a costed load test before launch. And the uncomfortable fact that platform spending caps are usually alerts, not brakes. See the bill that arrives when you are not looking.

Will I be locked in to you?

No. Your accounts, your repository, your keys. Data access goes through one layer, so moving is a project of weeks rather than months. Replace us and you change one password. See how we work to spec and Firebase, Supabase, or your own.

Why does the invisible part cost as much as the app?

Because it is where scale, cost and reliability are decided. Uptime, success rate under bad conditions, speed of the one operation that matters, and behaviour at 10x volume: those numbers are what you are actually buying.

How do I judge backend work if I cannot see it?

Uptime, success rate under bad conditions, speed of the one operation that matters, and behaviour at 10x volume. We hand you all four in writing.

Can you connect to the system we already use?

Almost certainly, including old ones. What matters is what happens when that system is down. We define that for every integration. See connecting to everything else you already run.

What happens if a provider changes their API?

Versions are pinned and monitored, so it becomes a ticket rather than an outage.

Do you do REST or GraphQL?

Both. We pick per project and explain the choice in plain words. See standards for the API itself.

Are my backups actually working?

They are on our projects, because we restore one as a test before handover. An untested backup is a rumour.

What does it cost to run each month?

You get the figure at todays volume and at 10x volume, before launch. It is step 7 of how we work.

Can our own developer take it over?

Yes. Documented API, runbook, and accounts already in your name. Handover is a normal ending, not a penalty.

Do you build the admin panel too?

That is a separate service, Web Apps & Admin Panels, usually scoped together with this.

Do you handle subscription billing?

The payment integration, yes. The billing logic, proration, dunning, upgrades mid-cycle, is its own hard problem and lives on SaaS Development.

Have something in mind

Tell us the problem. We bring the engineering.

A short call, an honest answer on whether we are the right team, and a scope you can hold us to.

Start a project