Mobile Backend And API Development — small scale stack.
For each requirement below, pick the option that fits your build — recommended first, then free and cheaper alternatives — or skip what your project doesn't need. Tap the info icon next to any requirement to see why it matters.
BaaS Platform / MBaaS Core
A piece of your stack you may or may not need, depending on scope. Pick the option that fits — or skip it if your project doesn’t require this capability yet.Pricing & free-tier limitsSupabase Free: 500MB DB, 1GB file storage, 50k MAU, 2 edge functions, 500k edge req / Pro $25/mo: 8GB DB, 100GB storage, 100k MAU, 2M edge req $0.025/10k over, backup $0.125/GB. Firebase Spark Free: 1GB Firestore, 5GB storage, 10GB hosting, 50k reads/day, 20k writes/day / Blaze Pay-as-you-go: $0.18/GB Firestore storage, $0.06/100k reads, $0.18/100k writes, $0.026/GB file storage. AWS Amplify Free 12mo: 5GB storage, 1000 build-min/mo / $0.01/build-min after, $0.15/GB hosted, AppSync $4.00/M queries. Back4App Free: 25k req/mo / Shared $19/mo 1M req $0.001 per 1k over.
Authentication & Identity (Auth + MFA)
How users sign up, log in, and are authorized. Getting roles and access control right early prevents painful rewrites.Pricing & free-tier limitsFirebase Auth Free: 50k MAU, unlimited anonymous, email/pass, social logins / Identity Platform: $0.0055/MAU after 50k, MFA SMS $0.06/verify, TOTP $0.02. Supabase Auth Free: 50k MAU included in project / Pro: 100k MAU included $0.00325/MAU over. Clerk Free: 10k MAU, 3 social providers / Pro $25/mo + $0.02/MAU over 10k, $10 per 1k orgs. Auth0 Free: 7.5k MAU, unlimited social, 2 tenant / Essentials $35/mo: 500 MAU then $0.07/MAU over, B2C Pro $240/mo 1k MAU $0.20/MAU over.
Real-time Sync & Database
Persistent storage for your app’s data — users, products, orders. The single most important architectural decision for most projects.Pricing & free-tier limitsFirebase Realtime DB Free: 1GB stored, 10GB/mo transfer, 100 concurrent / Blaze: $5/GB stored, $1/GB transferred, $0.001 per 1k concurrent-hr over. Supabase Realtime Free: 200 concurrent connections, 2M messages/mo / Pro $25/mo: 500 concurrent, 10M msgs/mo $2.50/M extra, 500 channels. Pusher Free: 200k msgs/day, 100 concurrent, 2k msg size / $29/mo: 1M msgs/day, 500 conn $0.05/10k extra msgs. Ably Free: 6M msgs/mo, 200 conn, 200 channels / Standard $99/mo: 20M msgs, 1k conn $0.75/M extra, $5 per 1k extra conn.
Push Notification Service (FCM/APNs/Web)
Reaches users on their phone via SMS or push. Useful for verification codes and re-engagement; watch the per-message cost.Pricing & free-tier limitsFCM Free: unlimited Android/iOS/web pushes, 1M topics, no per-message fee, analytics included. OneSignal Free: 10k subscribers, unlimited mobile pushes with branding, 10k emails/mo / Growth $9/mo: 10k included then $0.002/sub over 10k, $6 per extra 1k emails, $0.01 per SMS. Pusher Beams Free: 10k subs / $199/mo: 50k subs $0.002/sub over. Airship: $500/mo starter 50k subs, $0.01 per extra 1k pushes, $0.003 per SMS, $0.005 per in-app.
File Storage for User Content (Avatars, Media)
Where you keep files users upload or you serve — images, videos, documents — and how fast they reach visitors around the world.Pricing & free-tier limitsR2 Free: 10GB storage, 10M Class A ops, 10M Class B reads/mo / Paid: $0.015/GB-mo storage, $4.50/M Class A, $0.36/M Class B, zero egress fee. Supabase Storage Free: 1GB / Pro 100GB included then $0.021/GB-mo over, $0.09/GB egress. S3 Free 5GB 12mo / Standard: $0.023/GB-mo first 50TB, $0.09/GB egress to internet, $0.005/1k PUT, $0.0004/1k GET. Backblaze B2: $0.006/GB-mo storage, $0.01/GB egress, 10GB free forever.
API Gateway + Rate Limiting
Controls and protects your APIs — quotas, abuse prevention, and firewalls. Important once you have real traffic or many clients.Pricing & free-tier limitsCloudflare Free: 100k Worker req/day, 5 WAF rules, 10k KV reads/day / Pro $20/mo: 10M Worker req/mo $0.15/M over, 20 WAF rules, API Shield schema validation, rate limiting 1 free rule 10 rules $5/mo extra. AWS API Gateway HTTP: $1.00/M req first 300M $0.90 after, Free 1M req/mo 12mo, REST $3.50/M req. Kong Konnect Free: 1M API calls/mo / Plus $250/mo: 5M included $0.08/M over, 1 portal, 3 data planes. Apigee Pay-as-you-go $0.60/M req $0.15 per 10k analytics.
Payment API & In-App Purchase Infra
Moves money — charges, payouts to sellers, taxes, fraud checks. Highest-stakes integration: get it wrong and you break compliance or lose revenue.Pricing & free-tier limitsRevenueCat Free: up to $2.5k MTR or 10k MAU, webhooks, integrations / Startup $120/mo: 10k MAU included $0.02/MAU over, 1% fee over $2.5k MTR after. Stripe: 2.9% + $0.30 per charge US, no monthly fee, Billing $0.5% recurring, Radar free $25k, In-app purchase via StoreKit free Apple 15-30%. Paddle: 5% + $0.50 per transaction no monthly, includes tax. Adyen: Interchange++ + $0.11 + 0.06% platform fee, $0.10 per stored card, $150/mo min invoice.
Background Jobs & Queues for push/async
A piece of your stack you may or may not need, depending on scope. Pick the option that fits — or skip it if your project doesn’t require this capability yet.Pricing & free-tier limitsSQS Free: 1M requests/mo always free / Standard $0.40/M requests after, FIFO $0.50/M. Inngest Free: 50k step runs/mo, 1 month retention, 2 concurrency / $20/mo: 100k runs $0.20/1k over, 10x concurrency. Cloud Tasks: $0.40/M tasks + $0.15/M HTTP target invocations, Free 1M ops/mo. BullMQ Cloud $20/mo 100k jobs $0.15/1k over. Sidekiq Cloud $99/mo 100k jobs $0.10/1k over.
Database for Mobile Backend (Primary OLTP)
Where your code actually runs and serves requests. Picking the right host affects speed, scaling, and how much ops work you do.Pricing & free-tier limitsSupabase Free: 500MB Postgres, shared 2 vCPU, 7d backup / Pro $25/mo: 8GB storage, 4 vCPU, PITR 7d $10 per extra 7d, $0.125/GB storage over, $0.10/GB egress. Firestore Free: 1GB storage, 50k reads/day, 20k writes/day / $0.18/GB-mo storage, $0.06/100k reads, $0.18/100k writes, $0.02/100k deletes. PlanetScale Free: 5GB, 1B reads/mo / Scaler $39/mo 25GB 10B reads $0.15/GB over. Neon Free 0.5GB / Launch $19/mo 10GB $0.10/GB over, $5 per 10M compute units.
Mobile API Monitoring & Crashlytics
Tells you when things break and why. You cannot fix what you cannot see — this is how you keep downtime short.Pricing & free-tier limitsFirebase Crashlytics Free: unlimited crash reports, non-fatals, ANRs, BigQuery export free, 30d retention. Sentry Free: 5k error events/mo, 10k performance transactions, 1GB attachments / Team $26/mo: 50k errors $0.00036/error over, perf $0.00013/transaction over. Datadog APM $31/host/mo, Free 1M APM traces 15d retention $0.10/1k traces over, RUM $1.50/1k sessions. New Relic Free: 100GB ingest/mo, 1 full user / $0.35/GB over, $99/user/mo pro.
Offline Sync & Conflict Resolution
A piece of your stack you may or may not need, depending on scope. Pick the option that fits — or skip it if your project doesn’t require this capability yet.Pricing & free-tier limitsWatermelonDB OSS MIT free local SQLite + sync adapter DIY. PowerSync Free: 2k MAU, 500MB sync storage, 5M sync ops / Starter $49/mo: 10k MAU $0.015/MAU over, 5GB storage, 50M ops $0.10/M over. Couchbase Capella Free: 5GB / $32/mo cluster credit ~ 1GB RAM, $0.09/GB storage. ObjectBox Sync Free: offline only / $499/mo server unlimited devices up to 5k, then $0.08/device/mo over 5k. AWS AppSync offline $0.50 per 1M offline syncs.
Secrets Management & Env Config
Stores API keys and credentials safely, separate from your code. Leaking secrets is one of the most common breaches.Pricing & free-tier limitsInfisical Cloud Free: 2 projects, 100 secrets / Starter $19/mo/user 10 projects $0.02/secret over. Doppler Free: 100 secrets, 1 environment / Team $8/user/mo 5k secrets, audit logs $0.50/100 secrets over. AWS Secrets Manager: Free 30d trial / $0.40/secret/mo + $0.05/10k API calls, 10k free calls. HashiCorp Vault Cloud $0.32/hr cluster ~ $230/mo Standard + $0.40/secret/mo HSM, Enterprise $0.60/hr.
CI/CD for Mobile API Deployments
Automates testing and deploying your code. Saves enormous time and prevents “works on my machine” releases.Pricing & free-tier limitsGitHub Actions Free: 2k Linux min/mo, 500MB storage / Team $4/user/mo 3k min, $0.008/min Linux over, $0.16/GB-month storage, $0.008/min macOS M1 $0.12/min. GitLab Free: 400 CI min/mo / Premium $29/user/mo 10k min $0.008/min over. Codemagic Free: 500 min/mo macOS / Pay-as-you-go $37.50/mo 2500 min $0.05/min over. CircleCI Free: 6k credits/mo ~1k min / Performance $15/mo 25k credits $0.00006/credit over.
CDN & Edge Caching for API
Where you keep files users upload or you serve — images, videos, documents — and how fast they reach visitors around the world.Pricing & free-tier limitsCloudflare Free: unlimited bandwidth, 3 page rules, 10MB max upload, cache everything / Pro $20/mo WAF + 100MB upload $5/mo per 10 extra page rules. Bunny.net $1/mo min: $0.01/GB NA/EU $0.03/GB Asia $0.06 SA, $0.005/1M requests, free SSL. Fastly $50/mo min includes $50 usage: $0.12/GB NA $0.19 Asia $0.008/10k req, TLS $20/mo domain. Akamai Enterprise $500/mo min $0.08/GB delivery $0.02/1k req over.
Search & Indexing for Mobile
Lets users find things fast. A slow or missing search directly costs engagement and conversions.Pricing & free-tier limitsTypesense OSS free self-host / Cloud Free: 0.5GB RAM 10k docs / $40/mo: 2GB RAM 500k docs, 100k searches/mo $0.03/10k over. Meilisearch Free: 10k docs 10k searches / $30/mo: 100k docs, 500k searches $0.20/10k extra. Algolia Free: 10k records, 10k search req/mo / Grow $0.50 per 1k records/mo + $0.50 per 1k search req, base $35/mo. Elastic Cloud Free 14d / $95/mo 2GB RAM 48GB storage $0.15/GB over.
Analytics & Event Ingestion (Mobile)
Lets external services notify you of events in real time. Core to integrating payments, KYC, and third-party workflows.Pricing & free-tier limitsPostHog Free: 1M events/mo, 5k session replays, 1M feature flag req / $0.000248/event after 1M, $0.005/replay over. Firebase Analytics Free: unlimited events (500 distinct event names), BigQuery export $0.02/GB storage + $5/TB query. Mixpanel Free dev: 100k MTU/mo / Growth $20/mo base + 100k MTU $28/mo $0.28/1k MTU over. Amplitude Starter Free 50k MTU / Growth $995/mo 300k MTU $0.0035/MTU over, $0.08 per 1k extra events.
Email & OTP Delivery Service
Where you keep files users upload or you serve — images, videos, documents — and how fast they reach visitors around the world.Pricing & free-tier limitsResend Free: 3k emails/mo, 1 domain, 1k contacts / Pro $20/mo: 50k emails, $0.0008/email over, $0.0015 per attachment. AWS SES Free 3k msg/mo from EC2 / $0.10/1k emails after $0.12/GB attachments, 62k free if on EC2 62k included. Twilio Verify: $0.05 per SMS verify, $0.02 per email OTP, WhatsApp $0.07, silent network $0.05. SendGrid Free 100 emails/day / Essentials $19.95/mo 50k emails $0.0006/email over, dedicated IP $30/mo.
Deep Linking & Attribution Infra
A piece of your stack you may or may not need, depending on scope. Pick the option that fits — or skip it if your project doesn’t require this capability yet.Pricing & free-tier limitsNative App Links free (hosting needed). Firebase Hosting for App Links Free: 10GB transfer/mo / Blaze $0.15/GB transfer, $5/GB storage. Branch Free: 10k MAU, 500 referrals / Growth $59/mo: 30k MAU $0.005/MAU over $0.02/1k deep link events over. AppsFlyer Free: 500 non-organic installs / Growth $0.06/install $300/mo min $0.03 per install over. Adjust Starter $1299/mo 15k attributions $0.06/attr over, fraud $250/mo add-on.
API Documentation & SDK Generation
A piece of your stack you may or may not need, depending on scope. Pick the option that fits — or skip it if your project doesn’t require this capability yet.Pricing & free-tier limitsSwagger UI / Redoc OSS free self-host on GitHub Pages. Mintlify Free: 1 public project / Pro $120/mo: 5 projects, unlimited views $0.10 per 1k views over 50k, SSO add-on $50/mo. ReadMe Free: 3 spec versions / Pro $99/mo/maker: 10k API calls included $0.01/1k over, metrics $29/mo. Speakeasy Free: 1 SDK target / Pro $250/mo: 3 SDKs, $0.15 per generation over 500, $500/mo enterprise 10 SDKs.
How this small scale mobile backend and api development checklist works.
Each requirement below is something a small scale mobile backend and api development build typically needs. Pick one of the four researched options — recommended, free, cheaper or paid — add your own with "Other", or skip the requirement if your project doesn't need it. Nothing is mandatory; the plan on the right tracks what you've decided so nothing gets forgotten.
Your picks are saved in this browser automatically, so you can come back anytime. Options are researched per build level and refreshed as vendors change their plans — always verify details on the provider's page before committing.