How should a TypeScript finance application handle money accurately?

Avoid ordinary floating-point arithmetic for monetary calculations that require exact decimal behavior. Use integer minor units where appropriate, or a decimal library such as decimal.js with PostgreSQL NUMERIC columns. Define currency precision and rounding rules explicitly, and test serialization boundaries so API consumers do not silently convert exact values into imprecise numbers.

How do we make financial transaction APIs safe to retry?

Use idempotency keys backed by durable storage and uniqueness constraints, rather than an in-memory flag. Define how repeated requests return the original outcome and how conflicting payloads are rejected. In NestJS or Express, keep validation separate from transactional writes, and test concurrent requests plus failures between database updates and external calls.

Can TypeScript developers work within our SOC 2 controls?

We're comfortable working inside a client's SOC 2 security controls. Before access begins, clarify your approval process, repository permissions, development environment, and change-review requirements. For TypeScript services, discuss dependency scanning, secret handling, and production access boundaries. This describes working within your controls, not a claim that NextGen holds SOC 2 certification.

What matters when integrating Plaid into a TypeScript backend?

Keep access tokens on the server, validate incoming webhooks, and model connection states explicitly. For transaction synchronization, persist cursors and handle additions, modifications, and removals rather than assuming every response is new data. Plan for reauthentication and institution outages, and test reconciliation behavior with controlled fixtures alongside Plaid's sandbox.

How should we interview a TypeScript developer for finance software?

Use a small reconciliation or transaction-state exercise instead of only language trivia. Ask about decimal arithmetic, PostgreSQL transaction boundaries, authorization checks, and logs that avoid exposing sensitive account details. Our engineers are senior; many have 10+ years of experience. Book a 15-minute call to discuss the role and matching process.

Are your developers really based in the US?

Yes. Every engineer lives and works in the United States. No offshore subcontracting and no hand-offs to another team. That's written into the contract.

How fast can someone start?

Most teams interview matched engineers within a week of the first call. Start dates depend on your interview process.

US-based TypeScript developers · Finance

Senior TypeScript developers for finance and fintech teams, based in the US

Engineers who understand audit trails, reconciliation, and access controls, and who build systems your compliance team can sign off on.

Every engineer lives and works in the US
Works your hours, joins your standups
NDA and full IP assignment from day one

Book your 15-minute call Free, no-obligation. Takes 15 minutes.

Most teams interview matched engineers within a week

Not the right fit? We bring in a replacement

Book your call: tell us what you need

"NextGen scaled us from 2 to 7 dedicated engineers in under a quarter. Enterprise-grade capacity, zero agency drag."

Director of Engineering · FileForms

Sagemont Tax Services client review — VP, Product · Sagemont Tax Services

Bremar & Armstrong client review — Managing Partner · Bremar & Armstrong

"The AI intake agent handles our tier-1 patient calls with a hand-off cleaner than our old call center."

Head of Operations · Star Health

SEM Restaurant Group client review — COO · SEM Restaurant Group

Trademark Waste Solutions client review — Director of Operations · Trademark Waste Solutions

PlayerTrader client review — CTO · PlayerTrader

Guidant Global client review — Program Director · Guidant Global

PM Insights client review — Head of Engineering · PM Insights

"NextGen scaled us from 2 to 7 dedicated engineers in under a quarter. Enterprise-grade capacity, zero agency drag."

Director of Engineering · FileForms

"The AI intake agent handles our tier-1 patient calls with a hand-off cleaner than our old call center."

Head of Operations · Star Health

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Sound familiar?

Reconciliation and reporting still depend on manual spreadsheet steps.
Audit and access-control requirements slow every release.
Legacy systems hold critical numbers nobody wants to touch.
Offshore teams struggle with the precision financial data demands.

Get matched engineers this week One call. Matched profiles. You pick who to interview.

What our TypeScript engineers build for finance and fintech teams

Finance systems

Ledgers, reconciliation, reporting, and integrations with full audit trails.

Full-stack apps

TypeScript across the front-end and back-end with shared types.

JavaScript to TypeScript

Existing codebases migrated gradually without freezing feature work.

Talk to us about your project

Comfortable inside your security controls

We work inside your SOC 2 controls: your access policies, reviews, and change management.
Audit trails and least-privilege access built in from the start.
Every engineer is US-based and signs an NDA and IP assignment.

How it works

01
15-minute call
Tell us what you need built or fixed and where it's stuck.
02
Matched profiles
You meet US-based engineers with directly relevant work behind them.
03
You interview
Run your own technical interview. You only move forward with people you pick.
04
They start shipping
Onboarded into your repo, tools, and review process, with a weekly written update.

Book your 15-minute call

Hire US-based TypeScript finance developers from NextGen Coding Company for transaction APIs, reconciliation dashboards, and account integration workflows. Scope the role around your actual environment, whether that means NestJS on Node.js, React review screens, PostgreSQL records, or Plaid data ingestion. Critical engineering questions include monetary precision, duplicate events, access boundaries, and how operators investigate a transaction that does not reconcile.

TypeScript 5.x can make transaction states explicit, but it cannot validate a bank payload or make a multi-step update atomic. Pair typed contracts with runtime schemas, database transactions, and auditable state changes. We're comfortable working inside your SOC 2 security controls. Every engineer works from the US, follows your hours, and signs an NDA and full IP assignment before touching code.

// faq

Frequently asked questions

How should a TypeScript finance application handle money accurately?: Avoid ordinary floating-point arithmetic for monetary calculations that require exact decimal behavior. Use integer minor units where appropriate, or a decimal library such as decimal.js with PostgreSQL NUMERIC columns. Define currency precision and rounding rules explicitly, and test serialization boundaries so API consumers do not silently convert exact values into imprecise numbers.
How do we make financial transaction APIs safe to retry?: Use idempotency keys backed by durable storage and uniqueness constraints, rather than an in-memory flag. Define how repeated requests return the original outcome and how conflicting payloads are rejected. In NestJS or Express, keep validation separate from transactional writes, and test concurrent requests plus failures between database updates and external calls.
Can TypeScript developers work within our SOC 2 controls?: We're comfortable working inside a client's SOC 2 security controls. Before access begins, clarify your approval process, repository permissions, development environment, and change-review requirements. For TypeScript services, discuss dependency scanning, secret handling, and production access boundaries. This describes working within your controls, not a claim that NextGen holds SOC 2 certification.
What matters when integrating Plaid into a TypeScript backend?: Keep access tokens on the server, validate incoming webhooks, and model connection states explicitly. For transaction synchronization, persist cursors and handle additions, modifications, and removals rather than assuming every response is new data. Plan for reauthentication and institution outages, and test reconciliation behavior with controlled fixtures alongside Plaid's sandbox.
How should we interview a TypeScript developer for finance software?: Use a small reconciliation or transaction-state exercise instead of only language trivia. Ask about decimal arithmetic, PostgreSQL transaction boundaries, authorization checks, and logs that avoid exposing sensitive account details. Our engineers are senior; many have 10+ years of experience. Book a 15-minute call to discuss the role and matching process.
Are your developers really based in the US?: Yes. Every engineer lives and works in the United States. No offshore subcontracting and no hand-offs to another team. That's written into the contract.
How fast can someone start?: Most teams interview matched engineers within a week of the first call. Start dates depend on your interview process.

Start your project request

Tell us what you're building — engineering capacity, AI, QA, cloud, or a fixed-scope software engagement. Our NYC team responds within one business day.

Start Project Request View Pricing

New York City, USA(919) 342-7602 admin@nextgencodingcompany.com

// what to expect