Backend & API for Mobile Apps

Robust, secure, and infinitely scalable server-side systems that power your mobile app's data, logic, and integrations — engineered to perform reliably from day one through millions of users.

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Used by 150+

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The engine behind every great mobile app — built to handle real data, real users, and real business complexity without breaking a sweat.

At Webtech Nepal, we design and build the backend systems and APIs that make mobile apps function the way users expect. Every feature your app delivers to a user — authentication, data sync, payments, notifications, real-time updates, third-party integrations — depends entirely on a well-architected backend. A poorly designed server layer is the single most common reason great-looking mobile apps fail in production: they crash under load, leak data, or take too long to respond. We build backends that don’t just work — they scale, recover, and stay secure as your user base grows.

Whether you need a lightweight API to support a simple mobile utility or a high-throughput distributed system handling thousands of concurrent requests, we architect the right solution for your current needs and future ambitions. Our backend engineering combines deep expertise in Laravel, Node.js, and cloud-native services with a practical understanding of how mobile clients actually consume data — so every API we build is fast, predictable, and genuinely pleasant for mobile developers to work with.

We provide tailored solutions built on creativity, precision, and trust - ensuring quality results and a smooth experience every step of the way.

92%

Client satisfaction rate, fostering long-term relationships and repeat business

100+

Active users experiencing our design every day via products we made

30K

Delivered a high-quality project with exceptional attention to detail

We deliver creative solutions with quality results that make an impact.

Fields of Expertise

We build reliable, high-performance backend systems and APIs that give mobile apps the data, security, and scalability they need to serve real users at any scale.

Custom REST API Development

Well-structured, versioned REST APIs designed specifically around how mobile clients consume data — with consistent response formats, meaningful HTTP status codes, pagination, filtering, and field selection built in from the start. We follow REST best practices and document every endpoint with OpenAPI specifications so your mobile developers can integrate quickly, confidently, and without constant back-and-forth clarification.

GraphQL API Development

Flexible, query-driven APIs that let mobile clients request exactly the data they need — nothing more, nothing less. GraphQL eliminates over-fetching and under-fetching, reduces the number of round-trips on slow mobile networks, and makes it straightforward to evolve your data model without breaking existing clients. Ideal for apps with complex, interconnected data or multiple client types consuming different data shapes from the same backend.

Authentication & Authorization Systems

Secure, standards-compliant identity systems using JWT, OAuth 2.0, and OpenID Connect — with mobile-optimized token refresh flows, biometric authentication support, social login (Google, Facebook, Apple Sign-In), multi-factor authentication, and granular role-based access control. We design authentication flows that are secure without being tedious, keeping legitimate users moving and unauthorized access firmly blocked at every entry point.

Real-Time Backend & WebSocket Systems

Event-driven backend systems that push live data to mobile clients — powering chat, live notifications, collaborative features, live dashboards, and real-time order or delivery tracking. We implement WebSocket servers, Server-Sent Events, and managed real-time services like Firebase Realtime Database or Pusher — selecting the right technology for your latency requirements, concurrent connection volume, and infrastructure cost constraints.

Payment Gateway Integration

Secure server-side payment processing integrated with eSewa, Khalti, ConnectIPS, IME Pay, Stripe, and other gateways relevant to your market. We implement payment initiation, webhook verification, transaction status management, refund handling, and idempotency logic entirely on the server — keeping payment credentials and sensitive transaction data off the mobile device and ensuring no payment is counted twice or silently lost during network failures.

Push Notification Backend

Reliable, scalable notification delivery systems built on Firebase Cloud Messaging (FCM) and Apple Push Notification Service (APNs) — with device token management, topic-based broadcasting, user segmentation, notification scheduling, delivery tracking, and retry logic for failed deliveries. We build notification backends that handle millions of messages reliably, giving your app a direct, permission-based channel to re-engage users long after they close the app.

Database Architecture & Optimization

Thoughtful data modeling and database design using MySQL, PostgreSQL, MongoDB, or Redis — selected and structured for your app's specific query patterns, relationship complexity, and read/write ratios. We design schemas that stay performant as data volumes grow, implement strategic indexing, query optimization, and caching layers, and establish backup and replication strategies so your data is always fast to access and impossible to lose unexpectedly.

Offline Sync & Conflict Resolution

Server-side sync architectures that reconcile data between mobile clients and the backend after periods of offline use — handling conflict detection, resolution strategies, delta sync, and optimistic concurrency control. Reliable offline sync is technically one of the hardest problems in mobile backend development; we design systems that handle edge cases gracefully so users never lose data and never see inconsistencies, regardless of how poor their connection was when they made changes.

Third-Party API & Service Integration

Seamless server-side connections to the external services your app depends on — mapping services, SMS gateways, email providers, CRM platforms, ERP systems, social platforms, analytics pipelines, and cloud storage. We build integration layers with proper error handling, rate limit management, credential rotation, and response caching so your app's dependency on external services never becomes a point of fragility or unexpected downtime for your users.

API Security & Rate Limiting

Comprehensive API security hardening — including rate limiting and throttling to prevent abuse, input validation and sanitization against injection attacks, CORS policy configuration, API key management, request signing, and protection against common OWASP mobile API vulnerabilities. We treat security as a foundational engineering concern, not a checklist item — building defenses into the API architecture rather than patching them on after the fact.

API Documentation & Developer Experience

Comprehensive, accurate API documentation using OpenAPI (Swagger) specifications, with interactive testing environments, code samples in multiple languages, authentication guides, error code references, and versioning changelogs. Well-documented APIs dramatically reduce mobile integration time, eliminate ambiguity between frontend and backend teams, and make your API a reliable, professional product — whether consumed by your own developers or external partners and integrators.

Backend Maintenance & API Support

Ongoing care to keep your backend healthy, secure, and evolving with your product. We provide dependency updates, security patching, database performance tuning, API versioning management, infrastructure scaling, error monitoring and resolution, and feature additions as your app grows. A mobile app is only as reliable as the backend powering it — our maintenance plans ensure server-side issues are caught and resolved before your users notice them.

Our Process

Requirements Analysis & API Scoping

We begin by mapping every feature your mobile app needs against the backend resources, data flows, and business logic that must support it. This involves detailed conversations with your mobile development team, product stakeholders, and any existing system owners — producing a comprehensive API requirements document that specifies every endpoint, data model, authentication flow, and integration dependency before architecture decisions are made. Misaligned expectations between frontend and backend teams are the leading cause of costly rework; thorough scoping eliminates this risk at the cheapest possible stage.

Architecture Design & Technology Selection

We design the server architecture — selecting the right framework (Laravel, Node.js/Express, or NestJS), database stack, caching strategy, message queue, and hosting environment for your app's specific load characteristics, team's existing skills, and long-term maintainability requirements. We produce a system architecture diagram, entity-relationship diagram, and technology decision log before writing a single line of production code — giving all stakeholders a shared understanding of what is being built and exactly why each technical choice was made.

API Contract Definition & Mock Server Setup

Before backend implementation begins, we define the full API contract using OpenAPI specifications — documenting every endpoint, request and response schema, authentication requirement, error code, and pagination behavior. We then stand up a mock server from this specification, allowing your mobile development team to begin building against realistic API responses immediately — in parallel with backend development. This contract-first approach eliminates the most common bottleneck in mobile projects: frontend teams blocked waiting for a backend that isn't ready yet.

Backend Development & Database Implementation

Our backend engineers implement the API in sprint cycles — building endpoints, business logic, data models, authentication systems, and integrations against the agreed specification. We write automated unit tests and integration tests alongside the implementation code, not as a separate afterthought, and maintain a staging environment that mirrors production throughout development. Code reviews, static analysis, and security scanning are embedded into every pull request, ensuring quality is built in rather than inspected in at the end of the development cycle.

Integration Testing & Mobile Client Validation

We conduct end-to-end integration testing with the actual mobile clients — validating that every API endpoint behaves correctly under real network conditions, including slow connections, request timeouts, partial responses, and retry scenarios common in mobile environments. We specifically test authentication edge cases (expired tokens, concurrent sessions, forced logout), offline-to-online sync flows, and error state handling — the scenarios that are trivial to overlook but catastrophic for users when they occur in production with real data on the line.

Performance Testing & Security Audit

Before any production deployment, we conduct load testing to validate API response times and error rates under realistic concurrent user volumes — identifying slow queries, missing database indexes, memory leaks, and N+1 query problems that only manifest at scale. We also perform a targeted API security audit against OWASP API Security Top 10 vulnerabilities — including authentication bypass, excessive data exposure, injection risks, and improper rate limiting — producing a documented finding report with remediation actions completed before the API goes live.

Deployment, Monitoring & Ongoing Support

We deploy to production using automated CI/CD pipelines with zero-downtime deployment strategies — blue-green or rolling releases depending on your infrastructure — and activate full observability from the first real request: API response time monitoring, error rate alerting, database query performance tracking, and cost anomaly detection. Post-launch, we provide structured backend support covering dependency updates, security patching, query optimization, scaling adjustments as traffic grows, and new endpoint development as your app's feature set evolves with user needs and business priorities.