Your developer says the new booking app will be "serverless", and the quote has a line for cloud costs that nobody can pin down. You want to know what is serverless in plain words, who pays for what, and whether the monthly bill will surprise you.
This guide answers that for a shop, clinic, cafe or small factory owner. It uses only AWS and Google's own pricing pages and docs, so you can check every number yourself.
Quick answer
What is serverless, in plain words?
Serverless is a way of running your app where the cloud company owns, patches and scales the servers for you. Servers still exist. You just never rent one by the month, and you pay only for the time your code actually runs.
AWS describes it as "an abstraction of virtualized computing" where "the cloud provider manages the server resources your application runs on". In normal words: someone else worries about the machine.
What a "server" means here
A server is a computer in a data centre that stays on all day to answer your customers. With normal hosting (the rented computer your website lives on), you pay for it every hour, even at 3 a.m. when nobody visits.
What changes with serverless
With serverless, your code sleeps until a request comes in. A request is one action by a user, such as a form being sent or a payment alert arriving. The cloud wakes the code, runs it, and charges you for those few milliseconds.
Serverless vs a rented server: which fits your business?
A rented server is a fixed monthly cost for a computer that is always on. Serverless is a variable cost that follows how much people use your app. For low or uneven traffic, serverless is often cheaper; for steady all-day load, a server can be simpler to plan.
| Point | Serverless (for example AWS Lambda) | Rented server (for example AWS Lightsail) |
| How you pay | Per request and per millisecond of run time | Fixed price per month |
| Idle time | Free | Still billed |
| Busy festival day | Scales up by itself | Can slow down if the plan is too small |
| Who patches the system | The cloud company | Your developer |
| Time limit per task | 15 minutes on Lambda | No such limit |
| Smallest AWS price, Oct 2026 | Free up to the monthly allowance | US$5 a month for the smallest Lightsail plan |
When serverless makes sense
When a normal server is the better pick
How does AWS Lambda pricing work?
AWS Lambda bills you two things: the number of requests, and the run time multiplied by the memory you give the code. In the Mumbai region, as of October 2026, that is US$0.20 per million requests and about US$0.0000167 per GB-second. A monthly free allowance comes off first.
The two numbers on your bill
- Requests: every time the code is started, it counts as one request. AWS charges US$0.20 per million.
- Run time: AWS measures how long the code runs, rounded up to the nearest millisecond. That time is multiplied by the memory you chose, from 128 MB up to 10,240 MB.
- The result is in GB-seconds. One GB-second is code using 1 GB of memory for one second.
- The free allowance of 1 million requests and 400,000 GB-seconds a month comes off first.
Two worked examples (Mumbai region, October 2026)
These use AWS's own published rates. They cover the Lambda part only.
| Example | Requests a month | Run time and memory | Lambda bill |
| Clinic booking app | 3 lakh | 0.2 seconds, 512 MB | US$0, inside the free allowance |
| Busy shop app | 50 lakh | 0.3 seconds, 1 GB | About US$19 a month |
For the second example: 50 lakh requests at 0.3 seconds and 1 GB is 15 lakh GB-seconds. Take off the free 4 lakh, and 11 lakh GB-seconds cost about US$18.33. The 40 lakh paid requests add US$0.80.
The costs that sit outside Lambda
AWS's pricing page warns that using other AWS services, or sending data out, can add charges. So the database, file storage and data sent out to users are billed on their own. Ask your developer to list these as separate lines in the quote.
If you are planning a booking, billing or order app, ask for the hosting cost line by line before you sign. To have that worked out for your own app, see The Beyond Horizon's custom software development service for Indian businesses.
What about the new AWS Free Tier?
AWS changed its Free Tier for new accounts in July 2025. New customers now get US$100 in credits at sign-up and can earn up to US$100 more. The free account plan ends after six months or when the credits run out, whichever comes first.
Over 30 services, Lambda among them, still have an always-free monthly allowance. A practical tip: open the AWS account in your company's name and with your own email ID, then add the developer as a user. If the developer leaves, the account and the bills stay with you.
What is serverless outside AWS?
The same idea exists on other clouds. Google Cloud has Cloud Run, which Google calls "a fully managed application platform" for running code. Google's docs say that if there are no incoming requests, "even the last remaining instance will be removed", and you are not charged while it sits unused.
Cloudflare Workers and AWS Amplify are other common choices. The idea is the same everywhere: no server to look after, and the bill follows use.
What we have built on serverless platforms
Here are a few real projects from our own work.
What can go wrong with serverless?
The two common problems are a slow first request and a bill nobody is watching. Both are easy to manage once you know about them, and neither is a reason to avoid serverless for a small business app.
The slow first request
When code has not run for a while, the cloud has to start it fresh. AWS calls this a "cold start". AWS says cold starts typically happen in under 1% of calls and take from under 100 ms to over 1 second.
The bill nobody watches
Pay-per-use also means a bug that calls the code in a loop can run up a bill. Ask your developer to set a monthly budget alert in AWS Budgets on day one.
It can email you when spending passes, or is forecast to pass, the amount you pick. AWS notes there can be a delay between a charge and the alert.
Questions to ask your developer before you agree
- Which parts of the app will be serverless, and which will run on a normal server?
- What will the monthly cloud bill be at today's traffic, and at five times today's traffic?
- Which costs sit outside the compute bill: database, storage, data transfer?
- Is the cloud account in my company's name, with my email as the owner?
- Is a budget alert set, and who gets the email?
Getting the setup right
Once you know what is serverless and what a server costs, the choice comes down to your traffic. Serverless is a good fit for many small business apps, as long as someone has done the maths for your numbers. If you want a second opinion on a cloud quote or a plan for a new app, call or WhatsApp The Beyond Horizon on +91 75973 92744.