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★ Fintech app · stack

Best Tech Stack for a fintech app MVP

My opinionated stack for a fintech app MVP, layer by layer, with why I'd pick each tool and what would change my mind. Adjust the answers to fit your team.

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1What are you building?

Used for the cost estimate link below. The stack itself comes from your answers.

2Who's building it?
3Where does it run?
4What does it need?
5Any regulated data?
6How big in year one?
7How tight is the budget?

Your stack

Tech stack for Fintech app

10 layers, picked for your answers. Boring where it should be, so your effort goes into the product.

Cost this out →
  • Finance: treat your ledger as append-only, reconcile against the payment provider daily, and plan for a SOC 2 audit early.
  • Frontend

    Next.js (React + TypeScript)

    Server rendering for SEO, file-based routing and the biggest React ecosystem. TypeScript end to end catches whole classes of bugs before users do.

    What would change my mind
    A purely internal tool with no SEO needs, where a plain Vite + React single-page app is simpler.
    Alternative
    Vite + React SPA, or Remix / React Router
  • Mobile

    React Native with Expo

    One TypeScript codebase for iOS and Android that shares types, API clients and logic with the web app. Expo handles builds, signing and over-the-air updates.

    What would change my mind
    Heavy graphics, AR, or deep hardware integration, where native code earns its cost.
    Alternative
    Flutter
  • Backend / API

    Separate TypeScript API service (Node.js + Fastify)

    A dedicated service you can scale, monitor and audit on its own, sharing TypeScript types with the frontend.

    What would change my mind
    An early MVP with modest traffic, where Next.js route handlers inside the web app are enough.
    Alternative
    NestJS, or Go for a hot path
  • Database

    PostgreSQL on AWS RDS / Aurora

    Managed Postgres in your own cloud account with encryption, point-in-time recovery and audit logs. Financial data deserves transactions and constraints, which Postgres does well.

    What would change my mind
    Very early validation with synthetic data only. A serverless Postgres is fine until real customer data arrives.
    Alternative
    Google Cloud SQL for PostgreSQL
  • Auth

    Auth0 (or WorkOS for enterprise SSO)

    Hosted auth with MFA, audit logs and compliance attestations, so you aren't building security-critical login code yourself.

    What would change my mind
    Cost at large user counts. Revisit pricing tiers before you scale past the free and starter plans.
    Alternative
    AWS Cognito
  • Payments

    Stripe (Razorpay if your customers are mostly in India)

    Let a licensed provider hold the money movement while you keep your own ledger table in Postgres as the source of truth for balances.

    What would change my mind
    A market or payment method Stripe doesn't serve well, or merchant-of-record needs (tax handled for you), where Paddle or Lemon Squeezy fit.
    Alternative
    Paddle (merchant of record)
  • Hosting

    AWS or Google Cloud (SOC 2-ready setup)

    Customers and partners will ask about security controls. A major cloud with infrastructure-as-code makes audits far easier.

    What would change my mind
    Pre-revenue validation, where Vercel + a managed database gets you to the first users faster.
    Alternative
    Vercel for the frontend + AWS for the API and data
  • Background jobs

    Inngest or Trigger.dev

    Durable background functions with retries, schedules and a dashboard, written in the same TypeScript codebase.

    What would change my mind
    Very high throughput or strict data residency, which points to a queue in your own cloud.
    Alternative
    BullMQ + Redis
  • Analytics

    PostHog

    Product analytics, funnels, session replay and feature flags in one tool, with a generous free tier.

    What would change my mind
    A marketing-only site, where a simple privacy-friendly counter like Plausible is enough.
    Alternative
    Plausible (simple), or Mixpanel
  • Email

    Resend

    Reliable transactional email with a clean API and good deliverability defaults.

    What would change my mind
    Marketing campaigns and newsletters, which belong in a separate tool.
    Alternative
    Postmark

This is the stack I'd pick.

Want me to build on it? I ship MVPs on exactly this kind of stack.

Start with a scoping call
01

What makes a fintech app different

Fintech architecture starts with the ledger: an append-only record of every balance change, reconciled against the bank and payment provider. Everything else, including the UI, sits on top of that trust.

02

Risks to plan for

Mutable balances

Updating a balance column loses history. Record every movement as an entry and derive balances from them.

Reconciliation gaps

Your numbers, the bank's and the provider's drift apart. Automate daily reconciliation and alert on mismatches.

Security reviews

Partners will ask for SOC 2 and penetration tests. Infrastructure as code and audit logs make that survivable.

03

The stack at a glance

With the preset answers for a fintech app (you can change them above), this is the stack layer by layer.

Recommended stack by layer
LayerPickAlternative
FrontendNext.js (React + TypeScript)Vite + React SPA, or Remix / React Router
MobileReact Native with ExpoFlutter
Backend / APISeparate TypeScript API service (Node.js + Fastify)NestJS, or Go for a hot path
DatabasePostgreSQL on AWS RDS / AuroraGoogle Cloud SQL for PostgreSQL
AuthAuth0 (or WorkOS for enterprise SSO)AWS Cognito
PaymentsStripe (Razorpay if your customers are mostly in India)Paddle (merchant of record)
HostingAWS or Google Cloud (SOC 2-ready setup)Vercel for the frontend + AWS for the API and data
Background jobsInngest or Trigger.devBullMQ + Redis
AnalyticsPostHogPlausible (simple), or Mixpanel
EmailResendPostmark

Want the price tag too? Run the same product through the Fintech app cost estimate.

04

Questions founders actually ask

Can I use a backend-as-a-service for fintech?
For a demo, yes. For real customer money, use managed Postgres in your own cloud account so you control encryption, backups, access and audit logs.
Should AI touch financial calculations?
AI can read messy data and explain issues, but the arithmetic should stay in deterministic, tested code.
Do I need a banking licence?
Most MVPs partner with a licensed provider instead. The rules vary by country, so check with a lawyer early.
Why does the picker recommend boring technology?
Because an MVP's job is to find out whether people want the product. Mature, widely used tools have answers on the first page of search results, easy hiring and few surprises, so your risk stays in the product rather than the infrastructure.
Is this stack good enough to scale?
For the vast majority of startups, yes. Postgres, a mainstream framework and managed hosting carry companies a long way. When something does need to change, it's usually one layer at a time, and the picker shows what would trigger that change.
05

Stack by product type

Or start from a blank slate with the full tech stack picker.

06

More from the workbench

01 · Plan & scopeMVP Cost EstimatorPick features and who builds it. Get an hour-by-hour estimate, not an agency teaser.12 · Plan & scopeIdea → MVP SpecDescribe the idea. Get user stories, a must/should/won't list, a data model and a 6-week plan.02 · AI & LLMsLLM API Cost CalculatorYour monthly bill across Claude, GPT, Gemini and open models, side by side.

Fine print

Tools: on the house.
Engineer: by the hour.

The opinion was free. The implementation is where I come in.

I'm Himanshu, an AI and full-stack engineer. I build MVPs, AI agents and the growth plumbing around them for early-stage startups.

Hire me →My projects