C

Castle

Mobile home finance management with savings

Backend Software Engineer

Full-Time
$98k - $145k/yr
Mid
Bachelor's
Cambridge, MA, USA+1 moreMore locations: New York, NY, USA
Hybrid
Software EngineeringBackend Engineering

About the job

Requirements
  • Expertise with Python and the Django framework.
  • Expertise in RESTful API design.
  • Experience designing distributed systems.
  • Strong experience with cloud infrastructure and related tools.
  • Experience with continuous integration and continuous delivery tools and practices.
  • A bachelor's degree in Computer Science or a related field, or equivalent practical experience.
  • Experience building and shipping production applications.
Responsibilities
  • Develop and maintain REST APIs using Django.
  • Manage and optimize cloud infrastructure.
  • Oversee continuous integration and continuous delivery pipelines, along with monitoring, logging, and alerting systems.
  • Build a bill payment system for processing ACH and check payments.
  • Build an AI-powered system for recording payments made outside the Castle environment.
  • Build a data pipeline that transforms customer data into insights.
Desired Qualifications
  • Experience in consumer fintech.

About the company

Castle is a financial technology platform that helps homeowners manage their home-related finances through a mobile app. Users can track all home expenses in one place, pay bills, and identify potential savings from tax credits and rebates. The app consolidates financial data about property costs to give a comprehensive view of homeownership expenses, enabling more informed decisions. It operates on a subscription model with a two-week free trial and various plans targeted at United States homeowners. Compared to general personal finance apps, Castle focuses specifically on home finances, including renovation planning and eligibility for tax credits and rebates, to help users reduce overall homeownership costs while simplifying bill payments and expense tracking.

Company Size

11-50

Company Stage

Early VC

Total Funding

$2.6M

Headquarters

New York City, New York

Founded

2019

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Simplify's Take

What believers are saying

  • Castle’s September 2026 site refresh doubled down on homeowner payments and savings.
  • Castle’s tax-credit and rebate tooling sells concrete savings tied to renovations and energy upgrades.
  • Castle’s closing-payment tools expand revenue into attorneys and title companies.

What critics are saying

  • Castle lacks visible scale; 2026 materials still read like an early-stage niche startup.
  • Castle depends on pricey annual subscriptions while competing with banks, fintechs, and closing platforms.
  • If bill-pay errors or fraud losses spike, Castle’s trust proposition dies quickly.

What makes Castle unique

  • Castle bundles homeowner bills, payments, and savings discovery into one workflow.
  • Castle’s 2026 homeowner pages emphasize wire fraud protection and late-fee guarantees.
  • Castle also targets title and closing payments, extending beyond consumer budgeting.

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Growth & Insights

Headcount

6 month growth

7%

1 year growth

7%

2 year growth

-6%