Software Engineer, Payments Platform

What you'll be doing:

• Build a billing platform that scales from two countries to six. Make the right abstractions now so adding a new market is a config change, not a rewrite.
• Design and ship core billing capabilities: annual and monthly payment schedules, the Insify platform fee, VAT logic across jurisdictions, fee waiver rules, pro-rata refunds and renewals.
• Own our dunning flow across Adyen (credit card) and Twikey (SEPA): failure classification, retries, settling checks, partial payments and country-specific legal compliance (NL 14-day statutory warning, FR mise en demeure, and whatever comes next).
• Build resilient integrations with payment, banking and tax providers, and keep them observable, secure and easy to swap out.
• Handle multi-entity invoicing across Insify B.V., Insify Holding B.V., Insify NLD Agent B.V. and the entities we will add as we expand.
• Partner with finance, legal and compliance to turn regulatory and accounting requirements into clean, testable systems. Be the engineer in the room who can credibly push back when something doesn't make sense.
• Set the bar for engineering quality in the billing domain: idempotency, correctness, observability, recoverability. This is a domain where bugs cost real money.
• Own incidents and operational health. When something breaks in billing, the business notices, and you'll be one of the people who fixes it.

What you'll need:

• 3+ years of professional software engineering experience, ideally with TypeScript and AWS (Lambda, DynamoDB, event-driven architectures).
• A serious bar for correctness. You think in terms of edge cases, idempotency, consistency, retries, partial states and audit trails. You understand that "mostly works" is not acceptable when money moves.
• Strong fundamentals in distributed systems, data modelling and API design. You can spot the abstraction that will hold up across five countries and four payment providers.
• Comfort with complexity and ambiguity. Billing sits at the intersection of code, accounting, tax and law. You enjoy that instead of running from it.
• Ownership instinct. You think of the system as yours, not as someone else's ticket queue.
• Clear communicator. You can sit with finance, legal or a carrier and translate fuzzy requirements into a working system.
• AI in your workflow. You actively use AI for coding, debugging and tooling to move faster.

Nice to have:

• Experience with payment providers (Adyen, Stripe, Mollie, Twikey or similar), SEPA and card payment flows.
• Background in fintech, insurtech, billing, subscriptions or accounting systems at scale.
• Experience expanding a product or platform into new countries, including localisation of payments, tax and invoicing.
• Familiarity with VAT and multi-entity invoicing across EU markets.
• Strong observability instincts (Sentry, Datadog) and a track record of operating.

We offer:

Competitive compensation that reflects responsibility and impact. For mid-level engineer we have a range between 65-85k per year. 
Trust and autonomy: you’ll have real ownership and room to make decisions Space to grow and shape your role as Insify evolves.
A steep learning curve, with support from experienced teammates.
The opportunity to share in what we’re building, with equity for eligible roles once there’s mutual conviction on fit and impact.
A welcoming, central Amsterdam HQ where we work closely together: shared lunches, dogs in the office, whiteboards, and fun end-of-week drinks.
An international, ambitious team that enjoys building meaningful things together.