A guide to hiring an SMS developer
Text messages reach people who do not open email, which is why so many products use them for codes, reminders and alerts. Adding them looks like a small task, until the first message arrives late or twice. An SMS developer builds the sending, receiving and tracking so that texts behave like a dependable part of your product. The sections below explain the work, the signs of a strong candidate and the habits that make remote work go well. They are written for founders and product leads who depend on messages reaching customers.
What happens when a text is sent
Your system builds the message and hands it to a provider through an API. The provider passes it on and later reports what happened. Your system receives that report, often through a webhook, and saves it. If the customer replies, the provider sends the reply back to a web address you set up. Every one of these steps can fail on its own, so each needs a plan.
The jobs people hire for
Some teams want a first set of messages added to a new product, such as sign-in codes or order updates. Others want a two-way channel, where customers reply and staff answer from a screen. A third group needs a repair, because texts arrive late, arrive twice or leave no trace in the logs. Others need to change provider. Say which job you have, since each one asks for a different style of work.
Where an SMS developer fits among other roles
An API developer connects many services and may add messaging as one of them. A Node.js developer or other back-end developer builds the server that runs the queues and webhooks. The SMS developer sits between your product and the messaging provider and cares most about what happens to each message. For smaller products one person often covers all three roles.
When an SMS developer makes sense
- Customers say they never received their code or reminder.
- Your team cannot see which texts were delivered or failed.
- Replies from customers go nowhere or land in a personal phone.
- You want to change provider without a gap in service.
- Messages are sent by hand or by a spreadsheet, and you want them automatic.
If you only need a simple campaign to a list, a marketing tool may be enough. A developer who tells you so before you spend money is a good sign.
Ask about the failures
Anyone can send one message. Ask what the candidate did when texts stopped arriving, or arrived twice. A strong answer names the cause, such as a webhook that timed out and was retried, and the fix. Ask how they would know about a problem before a customer complained. People with real experience have a short list of stories and a habit of adding logs first.
Reading an SMS developer’s background
Request examples of messaging features they built, the provider they used and how they handled errors. Good answers include design choices, for instance how they avoided duplicate sends. Treat with care a background that only says a provider name. Calling an API is simple, and the care lies in what surrounds the call.
Questions to ask in interviews
- How do you stop a retry from sending the same text twice?
- How do you check that a webhook really came from the provider?
- Where would you store delivery reports, and how would your team read them?
- What do you do when the provider is down for an hour?
- How do you test messaging without sending real texts?
Good answers are specific and include real cases. Be wary of anyone who talks only about the happy path.
Try a paid mini project
Give each finalist one small piece of your own system. Good examples are a queue that sends test messages with retries, a webhook that saves delivery reports, or a screen that lists messages for one customer. Pay for the time spent. Then compare how the person tests, how readable the code is and how clearly they explain their choices.
Agree who owns the messaging accounts
Your provider account, keys and phone numbers should belong to your company. Give the developer access through their own login, and store keys in a safe place and not in the code. Agree who sees message content, since texts can hold personal details. Keep the code in a repository your company owns, and ask for a short note that explains how sending and receiving work.
Working with your team
Walk your developer through the real reasons customers get texts, and the questions they ask afterward. A brief weekly meeting and one shared list of tasks keep the whole team on the same page. Share your support team’s complaints early, because they point to the cases that matter most.
Common mistakes
- Sending straight from a web request with no queue or retry.
- Saving no record of delivery reports.
- Putting provider keys in the code or in a shared chat.
- Testing only with one phone number and one short message.
Looking at a wider role? Take a look at our API developers for many kinds of integrations, or our back-end developers for the server side.