Backend and Cloud Development for Mobile Apps

Why the backend decides how your app performs and scales

Users judge an app by the screens, but the screens are a thin layer over the backend: authentication, data, sync, notifications, payments and the integrations to everything else you run. Slow screens are usually slow queries. Lost data is usually a sync rule nobody wrote. A surprising cloud bill is usually an architecture chosen for launch and never revisited.

Tepia builds the backend as part of every app it delivers and scopes it during Discovery, not after the designs are finished. The answers decide between a managed platform like Firebase and a custom service, and between one cloud and another.

Tepia has run this decision across consumer apps, enterprise tools, IoT products like Maximum Controls and grocery ordering like MNC Go, and the stack below is the result of thirteen years of building and then supporting what was built.

Firebase versus a custom backend: the comparison

Firebase is the right backend for many first versions and the wrong one for many third versions. Tepia uses the table below to make the choice explicit, and often starts on Firebase with a plan to move specific services to a custom backend when the numbers call for it.

Tepia’s rule of thumb: Firebase when speed matters more than query flexibility and the data is simple; custom when the app is the business’s system of record, has reporting needs, touches payments or PHI, or integrates with more than two external systems. Many Tepia apps use Firebase Auth and Messaging alongside a custom API, which takes the best of both.

What Tepia builds into a mobile backend

A production backend from Tepia includes the pieces that are easy to skip at launch and painful to add later.

• Authentication and accounts. Email, phone, Apple and Google sign in, SSO for enterprise apps, role based access enforced on the server, and account deletion flows required by the App Store and Google Play.
• APIs. REST or GraphQL with versioning, pagination, rate limits and documentation, so the mobile app, a web portal and partners can share one backend. See API development and integration.
• Offline first sync. Queued writes, conflict rules and background refresh for apps used in the field, in plants or in buildings with poor signal.
• Push notifications. Segmented, scheduled and triggered notifications through Firebase Cloud Messaging and Apple Push, with analytics on opens, because notifications are the most direct retention lever an app has.
• Media and files. Upload, resize and serve through S3 or cloud storage with a CDN.
• Payments and integrations. Stripe, Square, Shopify, Salesforce, HubSpot, QuickBooks, ServiceTitan, Twilio, SendGrid, and Zapier or Make for lighter automations.
• Observability. Logging, error tracking, uptime checks and alerts, plus dashboards your team can read.
• Infrastructure as code. Environments for development, staging and production defined in code, with automated deploys and backups.

For AI features, Tepia adds a separate service for model calls, retrieval augmented generation and vector search against OpenAI and Anthropic APIs, kept apart from the core backend so it can change independently. Details are on AI integration services.

How Tepia approaches backend and cloud development

Backend work runs inside Tepia’s six phase process. During Discovery, Tepia’s system investigation covers your existing data, any current backend, hosting accounts and every third party integration, and user interviews surface the workflows that must be fast or must work offline.

Design for a backend means the data model, API contracts and sync rules, documented alongside the wireframes so the mobile and backend engineers build to the same spec. Development and Testing runs on Alpha and Beta schedules with a test plan that includes load testing, failure testing (what happens when a third party API is down), security checks and restore drills for backups, in addition to functional and user acceptance testing.

Training covers any admin console and the runbooks your team needs if you will operate the system. Launch includes data migration from spreadsheets or a previous system, the transition period and Tepia support reps on the rollout.

Every engagement has an assigned Tepia project manager, US based design and engineering leadership, and hand picked engineers working in US overlapping hours. The process is described at tepia.co/process.

Choosing AWS, Azure or GCP with Tepia

Tepia builds on all three major clouds and recommends based on what you already have. If your company runs Microsoft 365 and Entra ID, Azure usually simplifies identity and procurement. If you want the widest service catalog and most third party tooling, AWS is the default. If the app leans on Firebase, Google’s AI services or BigQuery for analytics, GCP keeps everything in one account.

Whichever cloud you choose, Tepia keeps the application portable with containers and infrastructure as code, so a change later is a migration rather than a rewrite. For the full mobile build that sits on top of this backend, start at custom mobile app development.

Frequently asked questions