Fintech products built for trust and scale
Specialist work falls apart when it never leaves the demo stage. Anything in production still needs auth, data handling, monitoring, and an interface people can use.
We document the prompts, tools, schemas, and day-to-day runbooks so your team can run the system after we hand it over.
Most people who reach this page are fintech startups and financial product teams. Secure fintech software development covering dashboards, payments, compliance-minded architecture, and AI-assisted workflows.
What you get
- Payment and billing systems
- Secure auth and audit trails
- Admin and customer portals
- API-first product platforms
- Documented handover and runbooks
- Help getting it deployed
How engagement works
Projects are shaped around fintech startups and financial product teams, so scope stays realistic, the first release comes quickly, and there is room to improve without a rewrite.
- 01
Discover
Goals, constraints, data sources, and success metrics, all settled before we touch architecture or prompts. Nothing here waits on a handover between separate teams.
- 02
Design
System design, AI/tool boundaries, interface direction, and interaction prototypes. On fintech software development projects we favour practical architecture over trendy defaults.
- 03
Build
Modern stack, clean architecture, evaluated AI behavior, and iterative demos you can react to. The work for teams in Berlin stays tied to the outcome you asked for.
- 04
Launch
Ship, monitor, harden, and keep improving models, tools, and product after go-live. You see progress on the critical path every week.
How we build it, and why
The stack is chosen per project, not applied from a template. For fintech software development work these are the defaults, and the reason each one is on the list.
- Next.js
- server rendering and static generation in one framework, so marketing pages stay fast and app routes stay dynamic
- NestJS
- structure and dependency injection on the backend, which keeps a growing API from turning into a pile of route handlers
- PostgreSQL
- relational integrity for data you cannot afford to get wrong
- Stripe
- payments, subscriptions, and the tax and invoicing edge cases you do not want to build
- AWS
- the services you grow into, once a managed platform stops being enough
What the first weeks look like
- Week 1
Spike the risky part
We build the thinnest possible version of payment and billing systems against your real data. If it is going to be a problem, it is better to know in week one than week six.
- Weeks 2-3
Harden the integration
Auth, rate limits, error paths, and the data contract. This is the work that separates a demo from something you can leave running.
- Weeks 4-6
Wire it into the product
The fintech software development stops being a standalone service and becomes a feature people use, with the interface and permissions that implies.
- Ongoing
Evaluate and tune
Behaviour gets measured against cases you care about, and we tune from that rather than from impressions.
Weighing up your options
There are three realistic ways to get this built. Each is the right answer for someone.
A solo freelancer
Cheapest per hour and fine for a contained task. The risk on fintech software development is breadth — one person covering design, backend, infrastructure, and launch usually means one of them is weak, and there is no cover when they are unavailable.
A local agency in Berlin
Same timezone and a face to meet, which genuinely matters for some teams. You are also paying Berlin startups hiring for shipping speed and modern stacks. rates for the whole team including the layers that never touch your fintech software development, and a local shortlist is a small shortlist.
Arcode
A small senior team. The people who scope the fintech software development write the code, you get weekly demos instead of status decks, and the engagement ends when the thing is live and handed over.
Work we have shipped
React Email Templates
Email systems · Resend
Reusable React Email templates sent through Resend for production transactional mail.
Freelance email kit using React Email, Resend, TypeScript, and Tailwind to create and send branded emails from a React app.
- · Reusable email templates
- · Resend delivery integration
- · TypeScript-safe composition
- · Tailwind-styled layouts
React Email · Resend · TypeScript · Tailwind
Horizan Labs
Frontend · Internship
Marketing website contribution during the Arsol internship, focused on responsive UI and frontend delivery.
Early-career site work at Arsol using React, Next.js, and Tailwind to help ship the Horizan Labs web presence with the team.
- · Responsive marketing pages
- · Team-based frontend delivery
- · Modern React/Next stack
- · UI performance and accessibility focus
React · Next.js · Tailwind · MySQL
Case Management Hub
Full-stack engineer · NestJS · Next.js
HIPAA-compliant healthcare SaaS for 150+ US organizations, with dual databases, realtime collaboration, billing, and secure client portals.
Enterprise case management platform for healthcare and social-work organizations with encryption, realtime messaging, Stripe billing, Zoom, and calendar sync.
- · HIPAA-ready architecture with encryption and audit logging
- · Realtime collaboration via Socket.io + Redis
- · Client portal and role-based access control
- · Stripe billing and document workflows
Next.js · NestJS · TypeScript · MongoDB · Redis · Socket.io
Working with teams in Berlin
Berlin startups hiring for shipping speed and modern stacks. We work with clients in Berlin remotely and keep overlapping hours in CET/CEST. We usually collaborate in German/English.
How we work with Berlin teams
Berlin is three to four hours behind us, so there is a full shared afternoon. Berlin teams tend to move fast and decide in writing, which suits the way we run a backlog.
What Berlin clients usually need
Berlin is the most startup-weighted market we work in outside the US: early-stage products that need to be live before the next raise, and AI features added to products that already have traction.
Contracts, data, and compliance
We invoice in EUR with reverse-charge VAT. GDPR is scoped into the build, with EU-hosted data by default and a DPA provided as standard rather than on request.
