Node.js, Laravel, Firebase, PostgreSQL
Hire Backend and Node.js Developers Who Build for Mobile Clients
When you hire backend and Node.js developers through us, you get engineers who design APIs around the realities of a phone: flaky networks, offline queues, old app versions still in the wild, and push notifications that must arrive once. You read the CVs, you run the interview, and the first two weeks are a trial on your own tickets.
This page covers the skills matrix by seniority, the interview questions worth asking, typical tasks and a two-week onboarding plan. For the delivery side, see our mobile app backend development service.
- Node.js on LTS releases, TypeScript first
- Laravel and Firebase when they fit better
- Two-week trial on your own tickets
- Code and cloud accounts stay yours
Why mobile apps need a different kind of backend developer
A backend for a website can assume a fresh client on every page load. A mobile backend cannot. Users keep old versions installed for months, so your API needs versioning and backward compatibility. Requests arrive from patchy connections, so endpoints must be idempotent and retries must not double-charge anyone. And a lot of the product lives outside the request cycle: push notifications, background jobs, webhooks from payment providers and admin tools for your operations team.
We screen for that mindset as much as for framework knowledge. Most of our backend work is in Node.js with TypeScript, with Laravel for teams already on PHP and Firebase when a managed backend gets you to launch faster. If you have not chosen yet, our guide to the best backend for mobile apps compares the options.
On runtime hygiene: according to the Node.js release schedule, production should run Active or Maintenance LTS releases only, and as of October 2026 v24 is the latest LTS. A developer who deploys a Current release to production is a yellow flag.
Backend developer skills matrix by seniority
Most mobile products need one mid-level backend developer with a senior available for architecture and security review, not a team of seniors.
| Skill | Junior | Mid-level | Senior |
|---|---|---|---|
| Node.js and TypeScript | Express or NestJS routes, async/await, typed DTOs | Event loop awareness, streams, error handling that does not crash the process | Service boundaries, queue design, choosing when Node.js is the wrong tool |
| API design | CRUD REST endpoints from a spec | Versioning, pagination, idempotency keys, OpenAPI docs | Designs APIs for offline-first clients and multiple app versions in production |
| Databases | Queries and migrations in PostgreSQL or MySQL; basic Firestore | Indexes, transactions, N+1 detection, Firestore security rules | Data modelling for growth, read replicas, migration strategy without downtime |
| Auth and security | Implements JWT or Firebase Auth from a pattern | Refresh tokens, role-based access, rate limiting, secrets management | Threat models auth flows; aligns API controls with OWASP MASVS for the app side |
| Integrations | Calls third-party APIs with retries | Payment webhooks, push via FCM and APNs, email and SMS providers | Designs reconciliation, dead-letter queues and failure handling across providers |
| Laravel / PHP | Controllers, Eloquent, Blade admin screens | Queues, policies, API resources, testing with Pest or PHPUnit | Upgrade planning across yearly Laravel majors; multi-tenant design |
| DevOps and observability | Runs the app in Docker locally | CI pipelines, environment config, structured logs, Sentry | Owns deployments, backups, monitoring alerts and incident runbooks |
Rates depend on seniority, hours and engagement length. Request a quote and we will price the exact profile you need.
Typical tasks for backend developers on a mobile product
These are the tickets a backend developer most often picks up in the first months.
REST or GraphQL APIs
Endpoints the mobile team can build against, documented in OpenAPI and covered by integration tests.
Auth and user accounts
Sign-up, social login, token refresh, roles and the account deletion flow Apple requires for apps with accounts.
Admin panels
Internal tools for support and operations. See our admin panel and dashboard development work.
Payments and webhooks
Stripe or local gateways, webhook verification and reconciliation. Details on payment gateway integration for mobile apps.
Notifications and jobs
Push via Firebase Cloud Messaging, scheduled jobs, queues and email or SMS triggers.
Performance and cost
Slow query fixes, caching, and cutting cloud bills that grew faster than the user base.
Interview questions to ask when you hire backend and Node.js developers
Ask for reasoning and follow up on anything vague. The goal is to see how the candidate thinks about failure, not whether they recall API names.
- What blocks the Node.js event loop, and how would you find it in production? Listen for CPU-heavy work, synchronous file or crypto calls, worker threads, and profiling or event-loop lag metrics.
- A mobile client retries a payment request after a timeout. How do you stop a double charge? Idempotency keys stored server-side, provider idempotency support, and returning the original result on retry.
- How do you change an API response when version 1 of the app is still installed on thousands of phones? Additive changes, versioned routes or headers, deprecation windows, and a minimum supported version check.
- Walk me through how you would design token refresh for a mobile app. Short-lived access tokens, rotating refresh tokens, revocation on logout and device loss, secure storage on the client.
- How would you find and fix an N+1 query? Query logging, eager loading or joins, and a test that fails if the query count grows.
- When would you choose Firebase over a custom Node.js backend, and when would you regret it? Speed to launch and realtime sync on one side; complex relational queries, reporting and vendor lock-in on the other.
- How do you handle a webhook that arrives twice, or out of order? Signature verification, storing event IDs, idempotent handlers, and state machines rather than assumptions about order.
- How do you keep secrets out of the repository? Environment variables or a secret manager, separate keys per environment, rotation, and scanning in CI.
- Describe a production incident you handled. Hands-on experience shows here: how they detected it, rolled back, communicated and prevented a repeat.
- How do you test an endpoint that calls a third-party API? Contract tests, mocks at the HTTP boundary, sandbox environments and a small number of real end-to-end checks.
Pair the questions with a review of one existing pull request from your codebase. How someone critiques code tells you more than any whiteboard task.
Shortlist backend developers you can interview this way
Send your stack, seniority and the first month of work. We will match profiles against it and include our own interview notes for each candidate.
Onboarding plan for the first two weeks
The two weeks double as the trial. A written plan makes the end-of-trial decision about evidence rather than gut feel.
Days 1–2: access and a local environment
Repository, cloud console with least-privilege roles, staging database, logs, Slack and the ticket board. Goal: the API runs locally against seeded data and the tests pass.
Days 3–4: read and fix
An architecture walkthrough, then a small bug fix merged through your normal review and deployed to staging. This tests the whole loop.
Days 5–7: first endpoint
A scoped endpoint with acceptance criteria, OpenAPI docs and tests, agreed with the mobile developer who will consume it.
Days 8–10: operations
Reviewing logs and alerts, fixing one slow query or noisy error, and documenting one undocumented part of the system.
Day 10: trial review
A short call to review pull requests, communication and estimates. You continue, request a replacement or stop.
How hiring works through us
You send a brief covering stack, seniority, hours and the first month of work. We return a shortlist with screening notes, you run the technical interview, and the developer you approve starts a two-week trial. The full process and vetting steps are on our hire mobile app developers page.
Backend developers often join a wider unit. If you need mobile, backend and QA together, a dedicated app development team may suit you better than separate hires. The trade-offs between models are on our app development engagement models page.
We sign your NDA before anything is shared, and the contract assigns all code to you. Cloud accounts, databases and API keys stay in your name; see NDA and IP protection.
What you get
- You interview every candidate
- Two-week trial on your tickets
- Code in your repository from day one
- Least-privilege access to your cloud
- Named project manager on our side
- Replacement if it is not working
When you should not hire a backend developer
If your app is a content viewer or a simple form flow, a managed backend set up once by a mobile developer may be all you need, and a full-time backend hire will run out of work. Our comparison of Firebase vs Supabase shows how far a managed backend can take you.
Also skip a dedicated hire if the work is a one-off integration. A short fixed-scope project is cheaper than a developer waiting for tickets.
Questions about hiring backend developers
Do your backend developers only work in Node.js?
No. Node.js with TypeScript is our most common stack, but we also place Laravel developers for PHP teams and developers experienced with Firebase and managed backends. Tell us your current stack and we will match to it rather than push a rewrite. A change of stack should come from a business or technical problem, not developer preference.
Can a backend developer also build our admin panel?
Usually, yes. Most admin panels are CRUD screens, reports and role-based access on top of the same API, which a mid-level backend developer handles well. If the panel is complex or customer-facing, add a frontend developer or designer so it does not become an afterthought.
Will the developer have access to our production servers?
Only the access you grant. We recommend least-privilege roles: staging access from day one, production access scoped to what the role needs, and every change through your CI pipeline. All accounts stay in your name and access can be revoked the moment the engagement ends.
How much does it cost to hire a backend developer?
It depends on seniority, stack, the hours you need covered and the engagement length. We do not publish a rate card, because a junior API developer and a senior who owns your infrastructure are very different roles. Send the brief and we will reply with a written quote and matching profiles.
Can a backend developer work US hours from Pakistan?
Partly. Pakistan is nine or ten hours ahead of US Eastern, so we arrange an evening shift for a two to four hour overlap with your morning, plus written handoffs. On-call cover is an option agreed in the contract, with the escalation plan in writing. If you need someone live for your full day, a local hire fits better.
What if the backend developer is not a good fit?
Tell us during or after the trial. We discuss what is missing, source a replacement you interview again, and arrange a handover. Because code, documentation and tickets already live in your systems, the next developer picks up where the previous one stopped.
Find the backend developer your app needs
Share your stack, seniority and hours. We reply within one business day and follow with matched backend developer profiles and our interview notes.