Software Engineer, Backend

About Primer: Primer is a premier, globally distributed financial technology pioneer building the unified automation infrastructure for international payments. By consolidating fragmented transaction flows, checkout funnels, and alternative provider networks into a single cohesive system, Primer gives enterprise finance and operations teams the absolute visibility required to reduce systemic complexity, improve success metrics, and capture more global revenue. Backed by world-class venture institutions—including Accel, Balderton, Tencent, ICONIQ, Sofina, and Peak XV Partners—Primer has secured over $100M in Series C financing to power the resilient, category-defining transaction layer that the world’s most sophisticated modern companies rely on daily.

Position Overview

We are seeking a highly sophisticated, systems-minded Software Engineer III, Backend to join our core Orchestration product group in a full-time remote capacity. In this high-calibre engineering seat, you will work within a small, elite cell that claims complete technical ownership of backend features from initial scoping through to live production monitoring. The Orchestration team builds the intelligent transactional engine that powers seamless payments across any provider, method, or geographical market—directing routing decisions, tokenization rules, API authentication, and automated fallback logic. This role demands a seasoned distributed systems developer who can deal thoughtfully with inheritance code complexity, defend error paths aggressively, and independently drive hard problems to resolution without requiring external signaling.

Key Responsibilities

• Backend Infrastructure Development: Design, build, and deploy high-availability server-side services natively optimized for performance, execution correctness, and absolute transactional scale.
• Intelligent Routing Engine Engineering: Code and refine the algorithmic routing layers, fallback logic parameters, and smart checkout components that orchestrate alternative payment flows safely.
• Distributed System Error Triage: Conduct structural audits across complex distributed code bases, writing production-ready code that proactively isolates and handles multi-point connection failures.
• REST API Contract Standardization: Model and maintain highly observable, predictable, and clean REST API endpoints, enforcing strict service boundaries across internal platform lines.
• Architecture Council Representation: Participate in deep technical discussions, formulate formal system design proposals, and advocate for clear service maintainability standards before the engineering council.
• Continuous Observability Monitoring: Take full operational responsibility for your code post-deployment, tracking live production impacts, assessing performance degradation, and leading incident triages early.
• Cross-Functional Scoping: Collaborate alongside engineering managers and product leads to review ambiguous technical requirements, map execution dependencies, and provide peer code reviews.

Required Skills & Qualifications

• Demonstrated professional software engineering history running backend development, distributed systems architecture, or high-volume transactional platform management.
• Deep, authoritative structural understanding of distributed systems patterns, network boundaries, and common production failure points.
• Hands-on operational experience designing, implementing, and optimizing robust, observable, and easy-to-reason-about REST APIs.
• Proven capability to independently manage technical feature direction end-to-end, considering automated monitoring frameworks and gradual rollout strategies.
• Outstanding verbal and written communication mechanics, with a clear capacity to state project risks and challenge system design decisions constructively.
• Location Context: Full-time remote-first operational parameters open exclusively to qualified backend engineers permanently located inside Poland, Hungary, Portugal, Romania, or South Africa.

Preferred Strategic Indicators (Nice to Have)

• Prior engineering experience building payment platform microservices, core banking integrations, ledger engines, or hyper-scale fintech infrastructure.
• Familiarity with containerized orchestration systems, streaming data tools, or asynchronous messaging loops.
• Demonstrated background managing large-scale application upgrades or refactoring highly complex inherited source codebases.

What We Offer

• The exceptional technical canvas to program, optimize, and scale the payment automation engine powering international merchant networks.
• Highly competitive compensation metrics paired with lucrative corporate share options and individual equity tracking.
• Profound work-from-home remote parameters providing total lifestyle autonomy and complete geographic independence across supported international tech hubs.
• Uncapped Holiday Blueprint: Enjoy absolute scheduling freedom with a minimum requirement of 25 paid vacation days to be taken annually.
• An extensive home office setup allowance (£500), worldwide co-working space access, an annual generous learning budget, premium private medical insurance plans, and participation in our legendary annual company retreats and technical workations.