Backend Engineer

New York, NY (Flatiron) Full-time
· In office 5 days 250k – 300k (+ Equity)

Axle is building the intelligent infrastructure for how capital moves on Wall Street.

Trillions of dollars in institutional capital get directed through a web of relationships, meetings, and decisions that still run on spreadsheets, email chains, and tools built over a decade ago. This is the layer where markets actually move, and we're at the forefront of rebuilding it.

We have replaced all of it with one platform, powered by AI agents that strip out the manual work and give bankers strategic leverage. Axle is quickly becoming the operating system for Wall Street's most important relationships.

The investment banks already running on Axle treat us as mission-critical, and we are just getting started. The problems we work on are high-stakes, data-dense, and critical to how markets function.

Our founding team blends Wall Street experience with engineering excellence, drawing on backgrounds at firms like Goldman Sachs, Bank of America, AWS, and Capital One. We lived the problem firsthand and built the platform we wished existed. Our tight-knit team in NYC is backed by top-tier VCs and former leaders from JPMorgan, Goldman Sachs, and Citadel.

We're looking to hire a Staff Backend Engineer. This is a hands-on IC role where you'll spend the vast majority of your time writing code, solving hard problems, and making architectural decisions that shape the platform as we continue to scale.

• Scale critical systems. Architect and implement solutions for high-throughput challenges across email delivery, reporting, calendar systems, and customer data integrations (Salesforce, SMTP, third-party APIs).
• Service architecture & isolation. Drive initiatives to modularize services within our backend, improving system resilience and enabling independent scaling of key components.
• Performance optimization. Identify and resolve bottlenecks in PostgreSQL queries, API latency, and data-intensive operations.
• Customer integration scalability. Ensure our platform handles growing volumes of customer data syncs (Salesforce, Snowflake, SMTP, etc.) reliably and efficiently as we onboard more clients.
• AI architecture. Shape the technical foundation for our AI capabilities, from system design and data pipelines to production integration.
• Developer experience. Level up the systems that keep the team moving fast.

• 8+ years building production backend systems, with strong experience in Java/Spring Boot (our primary stack) or a comparable backend framework where you can ramp quickly.
• Deep experience with relational databases at scale (ideally PostgreSQL). You've tuned queries, designed schemas for multi-tenant systems, and thought carefully about data partitioning.
• Production AWS experience where you've architected, deployed, and operated real systems.
• A track record of independently owning and shipping complex backend projects end-to-end.
• Strong technical judgment under ambiguity. You're comfortable making decisions with incomplete information and adjusting as you learn.
• Clear, direct communication. You can explain technical tradeoffs to engineers and non-engineers alike.

• Experience with high-volume data integrations, bulk email distribution, and large-scale API orchestration.
• Background in multi-tenant B2B SaaS.
• Infrastructure-as-code experience (Pulumi, Terraform).
• Experience building or integrating AI features into production systems.

We're building infrastructure that investment banks treat as mission-critical. You'll own hard backend problems — scale, performance, data integrations — and make architectural decisions that stick. No layers between you and the work. If you want to spend…