/fintech
Posts touching fintech.
17 posts
- March 22, 2026 5 min
Why every fintech startup eventually builds its own ledger
FinanceOps started with a third-party ledger. Within 18 months we built our own. Ledger semantics are too coupled to business rules for abstraction.
- /fintech
- /financeops
- /architecture
- /postgres
- /blog
- December 22, 2025 5 min
Building a fintech reconciliation engine that handles ten million transactions a day
PostgreSQL partitioned tables, Node.js worker pools, idempotent batch processing, and a custom diffing algorithm. Sub-minute reconciliation at ten million daily transactions.
- /fintech
- /financeops
- /postgres
- /architecture
- /node
- September 24, 2025 5 min
What payment reconciliation systems teach you about distributed consistency
Eventual consistency in payment reconciliation is a business requirement, not a technical compromise. Idempotency keys and reconciliation windows replaced two-phase commits.
- /fintech
- /financeops
- /architecture
- /postgres
- /blog
- July 21, 2025 4 min
Fintech compliance is not a checkbox. It is an architecture constraint.
Compliance that lives in code survives team turnover. Compliance that lives in spreadsheets does not.
- /fintech
- /architecture
- /financeops
- /blog
- April 28, 2025 5 min
The compliance audit that exposed every shortcut we took in our first year
Our first formal compliance audit surfaced 23 findings. Hardcoded keys, PII in logs, missing audit trails. None malicious, all "we will fix that later." The remediation sprint that followed.
- /fintech
- /security
- /cross-functional
- /architecture
- /experience
- January 27, 2025 5 min
DeepSeek R1 and the moment I realized open-source AI would change how we build internal tools
DeepSeek R1 shipped as a 671B open-source model matching GPT-4o benchmarks for under $6M training cost. Self-hostable reasoning models change the calculus for regulated fintech.
- /ai-ml
- /architecture
- /fintech
- /decision-making
- /blog
- January 6, 2025 5 min
AWS re:Invent announcements that actually matter for a three-person fintech team
Aurora DSQL, S3 Tables, Amazon Nova. re:Invent 2024 dropped a firehose of announcements, but most solve problems we will not have for years. Three that actually changed our roadmap.
- /aws
- /architecture
- /fintech
- /decision-making
- /blog
- November 25, 2024 4 min
Why our compliance team rewrites my API specs and I have learned to be grateful
In fintech, your API surface is a regulatory document. Our compliance officer started redlining my OpenAPI specs and improved our API design more than any tech review.
- /api-design
- /fintech
- /cross-functional
- /security
- /experience
- September 25, 2024 4 min
The night our database ran out of connections and what I learned about pooling
At 2am our payment processing froze. Every database connection was consumed by long-running report queries sharing a pool with transactions.
- /postgres
- /node
- /architecture
- /fintech
- /experience
- September 11, 2024 4 min
PostgreSQL 17 just dropped and COPY performance alone makes the upgrade worth it
PostgreSQL 17 shipped with 2x COPY performance, JSON_TABLE, and MERGE with RETURNING. The COPY improvement cut our nightly import from 12 minutes to under 6.
- /postgres
- /fintech
- /architecture
- /blog
- August 28, 2024 3 min
Why every API endpoint at FinanceOps returns the same error shape
Our frontend had seven different error format handlers. I standardized every endpoint to return the same discriminated union error shape.
- /api-design
- /typescript
- /node
- /fintech
- /blog
- August 14, 2024 4 min
The PostgreSQL query that took 47 seconds and how I got it to 3 milliseconds
A financial report query joined five tables across 2 million rows and took 47 seconds. The fix was not adding an index.
- /postgres
- /architecture
- /fintech
- /blog
- July 10, 2024 4 min
Building a payment reconciliation engine that catches every penny
When your product handles financial transactions, close enough is not a rounding strategy. Here is the three-way reconciliation engine I built.
- /fintech
- /financeops
- /postgres
- /architecture
- /blog
- June 12, 2024 4 min
How I use PostgreSQL as a job queue and why you probably should too
Every guide says use Redis or BullMQ for background jobs. I used PostgreSQL SKIP LOCKED and it handled thousands of jobs per day with zero additional infrastructure.
- /postgres
- /node
- /architecture
- /fintech
- /blog
- May 8, 2024 4 min
Designing a multi-tenant PostgreSQL schema that does not make you cry at 3am
Shared database, shared schema, row-level security. That was the bet. Here is how it played out.
- /postgres
- /architecture
- /fintech
- /api-design
- /blog
- May 1, 2024 4 min
What nobody tells you about building fintech: compliance is a product feature
I walked into FinanceOps thinking I was building software. Six months later I realized I was building a compliance platform that happens to have software around it.
- /fintech
- /financeops
- /startup-life
- /experience
- April 3, 2024 4 min
Why I chose PostgreSQL over MongoDB and how it shaped our entire fintech stack
Every fintech startup I talked to was defaulting to MongoDB. I went the other way and bet on PostgreSQL with strict schemas from day one.
- /postgres
- /architecture
- /fintech
- /decision-making
- /experience