Senior Software Engineer - 99Pledges

99Pledges a fundraising technology platform that powers online donation campaigns for organizations, teams, and individuals through our flagship product and through white-label deployments for partners. We process real money at scale, so correctness, reliability, and security are core to everything we build.

We're looking for a Senior Software Engineer who thrives in a mature, production Rails codebase, cares deeply about payment integrity, and can own features end-to-end from database schema to background jobs to the user-facing UI.

- Core fundraising platform : Campaigns, participants, donations, and the reporting and metrics that fundraisers rely on.

- Payment processing : Integrations with multiple payment providers (credit card, PayPal, and ACH/EFT), including automatic payouts, payment requests, and reconciliation.

- Multi-tenant white-label system : Branding, feature flags, and configuration that let partners run the platform under their own identity.

- Fraud prevention & trust : Fraud detection, device fingerprinting, and abuse mitigation that keep donors and organizations safe.

- Background processing : Reliable email delivery, data exports, and scheduled metric calculations.

- Database : PostgreSQL (production), with careful attention to migrations and denormalized/calculated fields for performance

- Monitoring : Honeybadger (errors), New Relic (performance), Datadog (migrating to)

- 3+ years building and maintaining production web applications, with strong Ruby on Rails experience.

- Solid grasp of relational database design, query performance, and safe migrations against large production tables.

- Experience integrating third-party APIs, ideally payment processors, and an appreciation for the failure modes that come with them (retries, idempotency, webhooks, reconciliation).

- A test-first mindset, you write well-tested code and treat correctness and edge cases as first-class concerns.

- Comfort working across the stack, including server-rendered views and front-end interactivity.

- Strong communication skills and the ability to explain technical tradeoffs clearly.

- Experience with payment/fintech systems, PCI considerations, or handling money in software.

- Familiarity with multi-tenant / white-label architectures.

- Experience with background job systems and asynchronous processing at scale.

- Experience with feature flagging and A/B experimentation (e.g., PostHog).

- We review designs before writing code and favor explicit, well-engineered solutions over clever ones.

- We prefer DRY code, thorough testing, and small, reviewable changes.

- We take production seriously: careful migrations, monitoring, and a bias toward correctness - because we handle donations that matter to real people and organizations.

You'll work on software that helps organizations raise money for causes they care about, with a small team where your work has direct, visible impact on both the product and the people who depend on it.