Senior Backend Engineer, Ledger
Own the double-entry core that every card, bill and bank line in Finly lands in.
Amsterdam · Hybrid, three days in office · Full-time
Salary band · published
€78,000 – €96,000
EUR per year · Senior · IC4
Role at a glance
- Team
- Ledger
- Reports to
- Ruth Adeyemi, Engineering Manager
- Level
- Senior · IC4
- Location
- Amsterdam, three days a week in the office
- Band
- €78,000 – €96,000 EUR per year
- Equity
- Options in the offer, four-year schedule
- Start
- From September 2026
About the role
The ledger is the part of Finly that nothing else works without. Every card authorisation, every supplier payment and every bank line lands in it, and the close our customers buy us for is only ever as good as what the ledger did the moment each of those arrived.
You would own that path end to end — the double-entry core, the matching engine that reconciles a bank line against what we already posted, and the migration that takes two years of a customer's history and makes it agree with ours. It is unglamorous, heavily tested work, and it is the reason a controller can shut a month in three days instead of twenty-one.
What you'll do
- Own the double-entry core and the invariants that keep it honest under concurrent writes.
- Extend the matching engine so a bank line, a card authorisation and a supplier payment reconcile without anyone touching them.
- Take a customer's two years of history through migration until both books agree, then retire the old one.
- Design the schema and the backfills for new ledger accounts, entities and currencies.
- Carry the ledger pager one week in six, alongside four other engineers.
What you'll bring
- Five or more years writing backend services that other people depend on being correct.
- Deep comfort with a relational database — transactions, isolation levels, and what actually happens under contention.
- Experience in money, accounting or another domain where approximately right is simply wrong.
- The habit of writing the test that fails loudly before the code that makes it pass.
- Enough written English to explain a decision, and the alternative you rejected, to someone who was not in the room.
Nice to have
- Worked with double-entry accounting, or had to explain a trial balance to an auditor.
- Kotlin or Go — the ledger is Kotlin, but we care far more about what you have shipped than what in.
- European bank feeds, PSD2, or the several ways SEPA settlement is not instant.
How we hire
Four steps, and a decision either way.
The same four for every role.No take-home that eats a weekend, and no round that exists to see whether you will put up with another round.
- Intro
A thirty-minute call
With the hiring manager, never a recruiter. You ask about the work, we ask what you have actually owned.
Same week you apply
- Craft
One piece of real work
A ninety-minute exercise taken from our own backlog — paid at your day rate if you would rather it were.
90 minutes, paid
- Team
Meet the three people
The ones you would sit beside, including whoever would review your code or sign off your ledger.
Two hours, one day
- Offer
A yes or a reason
A yes carries the band and the start date. A no carries why. Nobody is left to work it out from silence.
Inside two weeks
Benefits
Eight things you get on day one.
The same eight in Amsterdam and Lisbon.Nothing here is discretionary and nothing is a perk you have to ask twice for.
- Salary band, published
- Every advert carries its range. The same band in both cities, adjusted only for local tax.
- Equity in every offer
- Options on a four-year schedule with a one-year cliff, and ten years to exercise them.
- Three days in, two out
- Tuesday to Thursday in the office. Nobody schedules a meeting on the other two.
- Thirty days off
- Plus public holidays where you work, and the week between Christmas and New Year.
- Pension and health cover
- Employer pension contribution and full health insurance in both the Netherlands and Portugal.
- €2,000 a year to learn
- Conferences, courses and books. The budget renews each January and needs no approval under €500.
- Twenty weeks parental leave
- Fully paid, whichever parent you are, with a phased return across the month after it.
- A month in the other city
- Flights and a flat covered, once a year, in whichever office is not your own.
Apply
Send it and we will read it.
A CV or a link is enough —no cover letter, no form with fourteen fields.Every application gets a reply from the hiring manager, including the ones that are a no.